Tuesday, February 4, 2014
Super Boost 3 6A USB Charger Based on LM2700
This design is inspired by the Minty Boost but it fixes some of the issues that I had with it. The Minty Boost is limited to 600mA due to the LT1302 chip. The Super Boost uses the LM2700 which can push up to 3.6A. This will enable i-devices to draw up to there maximum of 1A which will enable a faster recharge.
Saturday, January 11, 2014
Under this circumstance cell phone jammer should be packed well
Under this circumstance, cell phone jammer should be packed well.
In 1999, the Groups industrial sales revenue of 21.5 billion yuan. In August 1997, Haier was the State Economic and Trade Commission identified as one of the six first technological innovation pilot enterprises, focusing on supporting the impact of the worlds top 500. "Difficult first" strategy, insist on playing the Haier brand exports, Haier is now 62 dealers in overseas development, more than 36,000 distribution points, products exported to the worlds top ten economic regions in Europe, America, Middle East, Southeast Asia 90 countries and regions, 1999, Haier brand export $ 138 million. Has five factories overseas, in the construction of eight, toward the the goal of the internationalization of enterprises. In April 1999, the trinity of Haier was set up on the road of internationalization, Haier has taken a solid step forward. Actually, the inspection process of the raw material of cell phone jammer is the vital and complicated process.
In 1997, the United States "appliance" magazine published the worldwide fastest growing home appliance business, Haier than GE, Siemens and other world famous, top of the list. March 25, 1998, Haier Group CEO Zhang was invited to board the Harvard University forum, "Haier culture activate the shock fish" cases formally written into the Harvard University teaching materials, marking Haier real to the world. November 30, 1998, the British "Financial Times" reported: in the companies rating the reputation of the Asia-Pacific region, Haier ranked seventh, is the only top ten Chinese enterprises. In 1999, the U.S. magazine "Fortune" to "the power of Chinas Haier much coverage of the results obtained by the title of the Haier Group. The inspector should check the rigidness, appropriateness of the raw material of cell phone jammer .This kind of design of cell phone jammer is the systematic study on the above problems
99 Fortune Forum in Shanghai conference Haier Group Zhang president as the sole participation of a Chinese home appliance entrepreneurs and make a speech. December 7, 1999, the British "Financial Times" published the worlds 30 most respected entrepreneurs ranking Haier CEO Zhang Ruimin Rong, ranked 26, which is the highest reputation of Chinese entrepreneurs worldwide. To speed up the enterprises to enter the worlds top 500 pace, the completion of the Haier "three parks, one school", the three parks Haier Development Zone Industrial Park, Haier Information Park, Haier Park, a school Haier University Department. June 25, 1999, the General Secretary Jiang Zemin visited Haier, when listening to Zhang reported by the President of Haiers goal is to enter the worlds top 500, said happily: "I look completely. The manufacture process of cell phone jammer should also be strictly controlled.
Read More..
In 1999, the Groups industrial sales revenue of 21.5 billion yuan. In August 1997, Haier was the State Economic and Trade Commission identified as one of the six first technological innovation pilot enterprises, focusing on supporting the impact of the worlds top 500. "Difficult first" strategy, insist on playing the Haier brand exports, Haier is now 62 dealers in overseas development, more than 36,000 distribution points, products exported to the worlds top ten economic regions in Europe, America, Middle East, Southeast Asia 90 countries and regions, 1999, Haier brand export $ 138 million. Has five factories overseas, in the construction of eight, toward the the goal of the internationalization of enterprises. In April 1999, the trinity of Haier was set up on the road of internationalization, Haier has taken a solid step forward. Actually, the inspection process of the raw material of cell phone jammer is the vital and complicated process.
In 1997, the United States "appliance" magazine published the worldwide fastest growing home appliance business, Haier than GE, Siemens and other world famous, top of the list. March 25, 1998, Haier Group CEO Zhang was invited to board the Harvard University forum, "Haier culture activate the shock fish" cases formally written into the Harvard University teaching materials, marking Haier real to the world. November 30, 1998, the British "Financial Times" reported: in the companies rating the reputation of the Asia-Pacific region, Haier ranked seventh, is the only top ten Chinese enterprises. In 1999, the U.S. magazine "Fortune" to "the power of Chinas Haier much coverage of the results obtained by the title of the Haier Group. The inspector should check the rigidness, appropriateness of the raw material of cell phone jammer .This kind of design of cell phone jammer is the systematic study on the above problems
99 Fortune Forum in Shanghai conference Haier Group Zhang president as the sole participation of a Chinese home appliance entrepreneurs and make a speech. December 7, 1999, the British "Financial Times" published the worlds 30 most respected entrepreneurs ranking Haier CEO Zhang Ruimin Rong, ranked 26, which is the highest reputation of Chinese entrepreneurs worldwide. To speed up the enterprises to enter the worlds top 500 pace, the completion of the Haier "three parks, one school", the three parks Haier Development Zone Industrial Park, Haier Information Park, Haier Park, a school Haier University Department. June 25, 1999, the General Secretary Jiang Zemin visited Haier, when listening to Zhang reported by the President of Haiers goal is to enter the worlds top 500, said happily: "I look completely. The manufacture process of cell phone jammer should also be strictly controlled.
Friday, January 10, 2014
25 Metres Range Short Wave AM Transmitter
Here the short wave AM Transmitter circuit design diagram. The circuit is quite simple and easy to build since it applies only a few electronic components. The primary feature of this transmitter is that it really is absolutely free from the LC (inductor, capacitor) tuned circuit and runs using a fixed frequency of 12 MHz that is very stable. An LC based tuned circuit is inherently unstable because of drift of resonant frequency due to temperature and humidity variations.
25 Metres Range, Short Wave AM Transmitter Circuit diagram :
Resistors R1 and R2 are utilized for DC biasing of transistor T1. The capacitor C1 gives coupling in between the condenser microphone and the base of transistor T1. In the same way, resistors R3, R4 and R5 give DC biasing to transistor T2.
The oscillator segment is a combination of transistor T2, crystal XTAL, capacitor C2, C3 and resistors R3, R4 and R5. The crystal is excited by a portion of energy from the collector of transistor T2 via the feedback capacitor C2. The crystal vibrates at its essential frequency and the oscillations happening because of the crystal are placed to the base of transistor T2 across resistor R4. Using this method, continuous undamped oscillations are acquired. Any crystal having the frequency in short wave range could be substituted in this circuit, even though the operation was tried using a 12 MHz crystal.
The Transistor T1 has 3 capabilities:
- The transistor features the DC path for extending +VCC source to transistor T2.
- It amplifies the audio signals which is generated by condenser mic.
- It injects the audio signal into the high frequency carrier signal for modulation.
The transmitted signals could be received on any short wave receiver without having distortion and noise. The range of this transmitter is 25 to 30 metres and may be expanded even more in case the length of the antenna wire is suitably extended together with good matching.
Simple Unipolar to Dual Supply Converter Circuit Diagram
Simple Unipolar to Dual Supply Converter Circuit Diagram. 817V The outputs in this circuit are independently variable and can be loaded unsymmetrically. The output voltage remains constant, irrespective of load and changes. By varying potentiometers R2 or R6, the output voltages can be conveniently set. Outputs can be varied between 8 and 17 V, so that the standard ±9, ±12, and ±15 V settings can be made.
Unipolar to Dual Supply Converter Circuit Diagram
This converter is designed for a maximum load current of 1 A and the output impedance of both supplies of 0.35 0. This circuit is not protected against shortcircuits, but uses the protection provided by the de input source. This circuit is ideal for biassing operation amplifier circuits.
Friday, December 27, 2013
Build a 10 Amp 13 8 Volt Power Supply Circuit Diagram
Sometimes amateurs like to home-brew their power supplies instead of purchasing one off the shelf at any of the major ham radio retail dealers. The advantage to rolling your own power supply is that it teaches us how they work and makes it easier to troubleshoot and repair other power supply units in the shack. It should be noted that there is no real cost advantage to building your own power supply unless you can get a large power transformer and heat sink for a super low price.
Of course rolling our own gives us the ability to customize the circuit and make it even more reliable than commercial units. The circuit in Figure 1 will give us 10 amps (12 amps surge) with performance that equals or exceeds any commercial unit. The circuit even has a current limiting feature which is a more reliable system than most commercial units have. Just like other commercial units, this circuit uses the LM723 IC which gives us excellent voltage regulation. The circuit uses 3 pass transistors which must be heat sinked. Resistor R9 allows the fine tuning of the voltage to exactly 13.8 volts and the resistor network formed by resistors R4 through R7 controls the current limiting.
The LM723 limits the current when the voltage drop across R5 approaches .7 volts. To reduce costs, most commercial units rely on the HFE of the pass transistors to determine the current limiting. The fault in that system is that the HFE of the pass transistors actually increases when the transistors heat up and risks a thermal runaway condition causing a possible failure of the pass transistors. Because this circuit samples the collector current of the pass transistors, thermal runaway is not a problem in this circuit making it a much more reliable power supply.
The only adjustment required is setting R9 to the desired output voltage of anywhere between 10 and 14 volts. You may use a front panel mounted 1K potentiometer for this purpose if desired. Resistor R1 only enhances temperature stability and can be eliminated if desired by connecting pins 5 and 6 of IC-1 together. Although it really isn’t needed due to the type of current limiting circuit used, over voltage protection can be added to the circuit by connecting the circuit of Figure 2 to Vout. The only way over voltage could occur is if transistors Q2 or Q3 were to fail with a collector to emitter short. Although collector to emitter shorts do happen, it is more much more likely that the transistors will open up when they fail.
10 Amp 13.8 Volt Power Supply Circuit Diagram
I actually tested this and purposely destroyed several 2N3055’s by shorting the emitters to ground. In all cases the transistors opened up and no collector to emitter short occurred in any transistor. In any event, the optional circuit in Figure 2 will give you that extra peace of mind when a very expensive radio is used with the power supply. The circuit in Figure 2 senses when the voltage exceeds 15 volts and causes the zener diode to conduct. When the zener diode conducts, the gate of the SCR is turned on and causes the SCR to short which blows the 15 amp fuse and shuts off the output voltage.
A 2N6399 (Tech America) was used for the SCR in the prototype but any suitable SCR can be used. While over voltage protection is a good idea, it should not be considered a substitute for large heat sinks. I personally feel the best protection from over voltage is the use of large heat sinks and a reliable current limiting circuit. Be sure to use large heat sinks along with heat sink grease for the 2N3055 transistors. I have used this power supply in my shack for several months on all kinds of transceivers from HF, VHF to UHF with excellent results and absolutely no hum. This power supply will be a welcome addition to your shack and will greatly enhance your knowledge of power supplies.
Parts
R1 1.5K ¼ Watt Resistor (optional, tie pins 6 & 5 of IC1 together if not used.)
R2,R3 0.1 Ohm 10 Watt Resistor (Tech America 900-1002)
R4 270 Ohm ¼ Watt Resistor
R5 680 Ohm ¼ Watt Resistor
R6,R7 0.15 Ohm 10 Watt Resistor (Tech America 900-1006)
R8 2.7K ¼ Watt Resistor
R9 1K Trimmer Potentiometer (RS271-280)
R10 3.3K ¼ Watt Resistor
C1,C2,C3,C4 4700 Microfarad Electrolytic Capacitor 35 Volt (observe polarity)
C5 100 Picofarad Ceramic Disk Capacitor
C6 1000 Microfarad Electrolytic Capacitor 25 Volt (observe polarity)
IC1 LM723 (RS276-1740) Voltage Regulator IC. Socket is recommended.
Q1 TIP3055T (RS276-2020) NPN Transistor (TO-220 Heat Sink Required)
Q2,Q3 2N3055 (RS276-2041) NPN Transistor (Large TO-3 Heat Sink Required)
S1 Any SPST Toggle Switch
F1 3 Amp Fast Blow Fuse
D1-D4 Full Wave Bridge Rectifier (RS276-1185)
T1 18 Volt, 10 Amp Transformer Hammond #165S18 (Tech America 900-5825)
R1 1.5K ¼ Watt Resistor (optional, tie pins 6 & 5 of IC1 together if not used.)
R2,R3 0.1 Ohm 10 Watt Resistor (Tech America 900-1002)
R4 270 Ohm ¼ Watt Resistor
R5 680 Ohm ¼ Watt Resistor
R6,R7 0.15 Ohm 10 Watt Resistor (Tech America 900-1006)
R8 2.7K ¼ Watt Resistor
R9 1K Trimmer Potentiometer (RS271-280)
R10 3.3K ¼ Watt Resistor
C1,C2,C3,C4 4700 Microfarad Electrolytic Capacitor 35 Volt (observe polarity)
C5 100 Picofarad Ceramic Disk Capacitor
C6 1000 Microfarad Electrolytic Capacitor 25 Volt (observe polarity)
IC1 LM723 (RS276-1740) Voltage Regulator IC. Socket is recommended.
Q1 TIP3055T (RS276-2020) NPN Transistor (TO-220 Heat Sink Required)
Q2,Q3 2N3055 (RS276-2041) NPN Transistor (Large TO-3 Heat Sink Required)
S1 Any SPST Toggle Switch
F1 3 Amp Fast Blow Fuse
D1-D4 Full Wave Bridge Rectifier (RS276-1185)
T1 18 Volt, 10 Amp Transformer Hammond #165S18 (Tech America 900-5825)
Thursday, December 26, 2013
Part 2 High Voltage Supply Circuit Diagram
This High-Voltage Supply Circuit Diagram uses a transistor oscillator and a voltage multiplier to charge CIO and CI 1 to a high voltage. When the spark gap breaks down, T2 produces a high-voltage pulse via the capacitance discharge of CIO and Cll into its primary. T2 is an auto ignition coil.
Read : High-Voltage Pulse Supply Circuit Diagram
Read : High-Voltage Pulse Supply Circuit Diagram
High-Voltage Supply Circuit Diagram
Wednesday, December 25, 2013
Simple Dc Ac Inverter Circuit Diagram
This dc-to-ac inverter is based on the popular 555. A 555 oscillator circuit drives a buffer amplifier consisting of Ql, Q2, and Q3.
The circuit operates at 150 to 160 Hz. Tl can be a 6.3-V or 12.6-V filament transformer as applicable.The frequency can be changed by changing the values of Rl and/or Cl.
Simple Dc/Ac Inverter Circuit Diagram
Tuesday, December 24, 2013
Current Monitor And Alarm
These circuits are intended for remote monitoring of the current consumption on the domestic mains line.
The circuit in Fig. I lights the signal lamp upon detecting a mains current consumption of more than 5 mA, and handles currents of several amperes with appropriate diodes fitted in the D, and D2 positions. Transistor Ti is switched on when the drop across D,-D2 exceeds a certain level. Diodes from the well-known I N400x series can be used for currents of up to I A, while lN540x types are rated for up to 3 A. Fuse F, should, of course, be dimensioned to suit the particular application.
A number of possible transistor types have been stated for use in the Ti position. Should you consider using a type not listed, be sure that it can cope with surges up to 700 V. As long as Ti does not con- duct, the gate of the triac is at mains potential via C,, protective resistor R2 and diode Da, which keeps C, charged. When Ti conducts, alternating current can flow through the capacitor, and the triac is triggered, so that Lai lights.
The circuit in Fig. 2 is a current triggered alarm. Rectifier bridge D4-D7 can only provide the coil voltage for Re, when the current through Di-D2 exceeds a certain level, because then series capacitor C, passes the alternating mains current. Capacitor C, may need to be dimensioned otherwise than shown to suit the sensitivity of the relay coil. This is readily effected by connecting capacitors in parallel until the coil voltage is high enough for the relay to operate reliably.
Finally, an important point: Many points in these circuits are at mains potential and therefore extremely dangerous to touch.
The circuit in Fig. I lights the signal lamp upon detecting a mains current consumption of more than 5 mA, and handles currents of several amperes with appropriate diodes fitted in the D, and D2 positions. Transistor Ti is switched on when the drop across D,-D2 exceeds a certain level. Diodes from the well-known I N400x series can be used for currents of up to I A, while lN540x types are rated for up to 3 A. Fuse F, should, of course, be dimensioned to suit the particular application.
A number of possible transistor types have been stated for use in the Ti position. Should you consider using a type not listed, be sure that it can cope with surges up to 700 V. As long as Ti does not con- duct, the gate of the triac is at mains potential via C,, protective resistor R2 and diode Da, which keeps C, charged. When Ti conducts, alternating current can flow through the capacitor, and the triac is triggered, so that Lai lights.
The circuit in Fig. 2 is a current triggered alarm. Rectifier bridge D4-D7 can only provide the coil voltage for Re, when the current through Di-D2 exceeds a certain level, because then series capacitor C, passes the alternating mains current. Capacitor C, may need to be dimensioned otherwise than shown to suit the sensitivity of the relay coil. This is readily effected by connecting capacitors in parallel until the coil voltage is high enough for the relay to operate reliably.
Finally, an important point: Many points in these circuits are at mains potential and therefore extremely dangerous to touch.
Source :http://www.ecircuitslab.com/2012/08/current-monitor-and-alarm-circuit.html
Monday, December 23, 2013
Simple RF Transmitter for PIR Sensors Circuit Diagram
This is the Simple RF Transmitter for PIR Sensors Circuit Diagram.
Sunday, December 22, 2013
Simple 2304 and 3456 MHz Power Amplifiers Circuit Diagram
This is a Simple 2304 and 3456 MHz Power Amplifiers Circuit Diagram
Saturday, December 21, 2013
Portable CD Player Adapter For Car
Whenever Im in the car listening to my favourite CD, it always happens; my batteries go dead. To solve that problem, I built this extremely simple regulator circuit. It steps down the 12V from the lighter socket to 9V which is used by the CD player. Different CD players (I have a Sony DiscMan) may require different voltages, so just use the correct regulator. All the 78xx series regulators have the same pin out, so the circuit is universal.
Part Total Qty. Description
C1 1 1000uF 25V Electrolytic Capacitor
C2 1 10uF 25V Electrolytic Capacitor
C3 1 1uF 15V Elextrolytic Capacitor
C4 1 0.1uF 15V Electrolytic Capacitor
U1 1 7809 Or Other Regulator (See "Notes") See Notes
MISC 1 Cigarette Lighter Plug, Plug For CD Player (See "Notes"), Heat Sink For U1, Wire, Case.
Notes
Part Total Qty. Description
C1 1 1000uF 25V Electrolytic Capacitor
C2 1 10uF 25V Electrolytic Capacitor
C3 1 1uF 15V Elextrolytic Capacitor
C4 1 0.1uF 15V Electrolytic Capacitor
U1 1 7809 Or Other Regulator (See "Notes") See Notes
MISC 1 Cigarette Lighter Plug, Plug For CD Player (See "Notes"), Heat Sink For U1, Wire, Case.
Notes
- The voltage your CD player needs will determine which regulator you use. For 9V, use the 7809. For 6V, use the 7806. For the unlikely 5V use the 7805. Remember that whatever regulator you use, you will need to heat sink it. The metal case or metal cover on the case makes a great heat sink.
- I built the circuit in a small case with the long wire to the cigarette lighter plug coming out one end, then another, slightly shorter wire going out the other end to the CD player.
- Triple check your wiring. You would hate to ruin an expensive CD player because you reversed one of the connections or hooked the regulator up backwards.
Friday, December 20, 2013
Pills Reminder
4 - 6 - 8 - 12 - 24 - 48 hours setting, LED or Beep Alert - 9V Battery Supply
A Pills Reminder is a device that operates a flashing LED (and/or a beeper) at a fixed hour interval. A choice of time-intervals as wide as possible is available with this circuit, namely 4, 6, 8, 12, 24 and 48 hours. At first you must choose the hour interval by switching SW1 to the desired value, then apply power by means of SW2. After the hour delay chosen has elapsed the LED will start flashing at 2Hz, i.e. two times per second.
This status will last until pushbutton P1 is pressed: then the LED will turn off, but the circuit will continue its counting and the LED will flash again when the same hour interval as before is reached. A noteworthy feature of this circuit, usually not found in similar devices, is that the internal counter is not reset when P1 is pressed: this allows a better time-interval precision.
Let us explain this feature with an example: suppose you have set the time interval to 24 hours and started the Pills Reminder at 8 oclock. Next day, at 8 oclock the LED will start flashing, but you, for some reason, notice the flashes at 8:10 and press P1 to stop the LED. With most devices of this kind, the counter will be reset, causing the LED to start flashing next day at 8:10 oclock. This will not happen with this circuit and the LED will start flashing next day always precisely at 8 oclock even if you pressed P1 at 9 or 10 oclock.
Circuit diagram:
R1______________10M 1/4W Resistor
R2,R3,R4_______100K 1/4W Resistors
R5,R7___________10K 1/4W Resistors
R6_______________1K 1/4W Resistor
C1,C2___________22pF 63V Ceramic Capacitors (See Notes)
C3______________22µF 25V Electrolytic Capacitor
C4,C5__________100nF 63V Polyester Capacitors
C6_______________1µF 63V Polyester, Multilayer Ceramic or Electrolytic Capacitor
IC1____________4060 14 stage ripple counter and oscillator CMos IC
IC2____________4040 12 stage ripple counter CMos IC
IC3____________4082 Dual 4 input AND gate CMos IC
IC4____________4075 Triple 3 input OR gate CMos IC
IC5____________4520 Dual binary up-counter CMos IC
IC6____________4001 Quad 2 input NOR Gate CMos IC
D1_____________5 or 10mm red LED
XTAL_________32.768 kHz Sub-miniature Watch crystal
P1_____________SPST Pushbutton
SW1____________2 poles 6 ways Rotary Switch
SW2____________SPST Toggle or Slide Switch
B1_______________9V PP3 Battery Clip for PP3 Battery
Alternative Clock Parts:
R8_______________1K 1/4W Resistor
R9_____________330K 1/4W Resistor
R10_____________20K 1/2W Cermet or Carbon Trimmer
R11______________1K 1/2W Cermet or Carbon Trimmer
C7_______________1µF 63V Polyester Capacitor
IC7____________7555 or TS555CN CMos Timer IC
Circuit Operation:
The clock of the circuit is made of a stable oscillator built around two inverters embedded into IC1 and a Watch crystal oscillating at 32.768kHz. This frequency is divided by 16384 by the internal flip-flop chain of IC1 and a 2Hz very stable clock frequency is available at pin #3 of this IC. IC2 counter and IC3A 4 input AND gate are wired in order to divide by 3600 the 2Hz clock, therefore, a pulse every 30 minutes is available at the clock input of IC5. The division factor of this IC is controlled by IC3B and the position of SW1A and B, selecting from six time-intervals fixed to 4, 6, 8, 12, 24 and 48 hours.
The set-reset flip-flop formed by IC6B and IC6C is set through IC4C each time a low to high transition is present at the pin of IC5 selected by SW1B cursor. IC6A and C4 provide to set the flip-flop also when a high to low transition is present at SW1B cursor. When the flip-flop is set, IC6D is enabled and the 2Hz frequency available at pin #3 of IC1 is applied to pin #13 of IC6D causing the flashing LED operation. The flip-flop can then be reset by means of P1. A master reset is automatically done at switch on by means of C6 and R7.
Alternative Clock:
Sometimes, the Watch crystal can be difficult to locate, or could be considered too expensive. For those willing to avoid the use of a Watch crystal and to accept less time accuracy, an alternative clock generator circuit is provided, directly oscillating at 2Hz, thus avoiding the use of divider ICs. A CMos 7555 Timer IC generates a stable 2Hz square wave, whose frequency must be accurately set by means of two trimmers.
R10 must be adjusted first for coarse tuning, then R11 for fine tuning. Setting precisely the 2Hz frequency of this oscillator is a rather difficult task, and can be done with great patience and the aid of a clock, a chronometer or, best, a digital frequency meter capable of measuring very low frequencies. In any case, after an accurate setup, this oscillator showed a very stable performance, not affected by battery voltage variations and an accuracy of about ±30 seconds per 24 hours interval.
Notes:
Read More..
A Pills Reminder is a device that operates a flashing LED (and/or a beeper) at a fixed hour interval. A choice of time-intervals as wide as possible is available with this circuit, namely 4, 6, 8, 12, 24 and 48 hours. At first you must choose the hour interval by switching SW1 to the desired value, then apply power by means of SW2. After the hour delay chosen has elapsed the LED will start flashing at 2Hz, i.e. two times per second.
This status will last until pushbutton P1 is pressed: then the LED will turn off, but the circuit will continue its counting and the LED will flash again when the same hour interval as before is reached. A noteworthy feature of this circuit, usually not found in similar devices, is that the internal counter is not reset when P1 is pressed: this allows a better time-interval precision.
Let us explain this feature with an example: suppose you have set the time interval to 24 hours and started the Pills Reminder at 8 oclock. Next day, at 8 oclock the LED will start flashing, but you, for some reason, notice the flashes at 8:10 and press P1 to stop the LED. With most devices of this kind, the counter will be reset, causing the LED to start flashing next day at 8:10 oclock. This will not happen with this circuit and the LED will start flashing next day always precisely at 8 oclock even if you pressed P1 at 9 or 10 oclock.
Circuit diagram:
Pills Reminder Circuit Diagram
Parts:R1______________10M 1/4W Resistor
R2,R3,R4_______100K 1/4W Resistors
R5,R7___________10K 1/4W Resistors
R6_______________1K 1/4W Resistor
C1,C2___________22pF 63V Ceramic Capacitors (See Notes)
C3______________22µF 25V Electrolytic Capacitor
C4,C5__________100nF 63V Polyester Capacitors
C6_______________1µF 63V Polyester, Multilayer Ceramic or Electrolytic Capacitor
IC1____________4060 14 stage ripple counter and oscillator CMos IC
IC2____________4040 12 stage ripple counter CMos IC
IC3____________4082 Dual 4 input AND gate CMos IC
IC4____________4075 Triple 3 input OR gate CMos IC
IC5____________4520 Dual binary up-counter CMos IC
IC6____________4001 Quad 2 input NOR Gate CMos IC
D1_____________5 or 10mm red LED
XTAL_________32.768 kHz Sub-miniature Watch crystal
P1_____________SPST Pushbutton
SW1____________2 poles 6 ways Rotary Switch
SW2____________SPST Toggle or Slide Switch
B1_______________9V PP3 Battery Clip for PP3 Battery
Alternative Clock Parts:
R8_______________1K 1/4W Resistor
R9_____________330K 1/4W Resistor
R10_____________20K 1/2W Cermet or Carbon Trimmer
R11______________1K 1/2W Cermet or Carbon Trimmer
C7_______________1µF 63V Polyester Capacitor
IC7____________7555 or TS555CN CMos Timer IC
Circuit Operation:
The clock of the circuit is made of a stable oscillator built around two inverters embedded into IC1 and a Watch crystal oscillating at 32.768kHz. This frequency is divided by 16384 by the internal flip-flop chain of IC1 and a 2Hz very stable clock frequency is available at pin #3 of this IC. IC2 counter and IC3A 4 input AND gate are wired in order to divide by 3600 the 2Hz clock, therefore, a pulse every 30 minutes is available at the clock input of IC5. The division factor of this IC is controlled by IC3B and the position of SW1A and B, selecting from six time-intervals fixed to 4, 6, 8, 12, 24 and 48 hours.
The set-reset flip-flop formed by IC6B and IC6C is set through IC4C each time a low to high transition is present at the pin of IC5 selected by SW1B cursor. IC6A and C4 provide to set the flip-flop also when a high to low transition is present at SW1B cursor. When the flip-flop is set, IC6D is enabled and the 2Hz frequency available at pin #3 of IC1 is applied to pin #13 of IC6D causing the flashing LED operation. The flip-flop can then be reset by means of P1. A master reset is automatically done at switch on by means of C6 and R7.
Alternative Clock:
Sometimes, the Watch crystal can be difficult to locate, or could be considered too expensive. For those willing to avoid the use of a Watch crystal and to accept less time accuracy, an alternative clock generator circuit is provided, directly oscillating at 2Hz, thus avoiding the use of divider ICs. A CMos 7555 Timer IC generates a stable 2Hz square wave, whose frequency must be accurately set by means of two trimmers.
R10 must be adjusted first for coarse tuning, then R11 for fine tuning. Setting precisely the 2Hz frequency of this oscillator is a rather difficult task, and can be done with great patience and the aid of a clock, a chronometer or, best, a digital frequency meter capable of measuring very low frequencies. In any case, after an accurate setup, this oscillator showed a very stable performance, not affected by battery voltage variations and an accuracy of about ±30 seconds per 24 hours interval.
Notes:
- Wanting the utmost time precision and if a digital frequency meter is available, a 5-50pF 50V Ceramic Trimmer Capacitor can be used in place of C2. It must be adjusted in order to read exactly 32.768kHz on the meter display with the input probe connected to pin #9 of IC1.
- A Piezo sounder (incorporating a 3KHz oscillator) can be added to provide a visual plus audible alert. It must be wired across pin #11 of IC6D and negative ground, respecting polarities. Remove D1 and R6 if the visual alert is not needed.
Author: RedCircuits - Copyright: www.redcircuits.com
Thursday, December 19, 2013
Simple Automatic Water Pump Controller Circuit Diagram
Simple Automatic Water Pump Controller Circuit Diagram is a series of functions to control the Automatic Water Pump Controller Circuit in a reservoir or water storage. As the water level sensor made with a metal plate mounted on the reservoir or water tank, with a sensor in the short to create the top level and a detection sensor for detecting long again made the lower level and ground lines connected to the bottom of reservoirs or reservoir.
The series of automatic water pump controller is designed with 2 inputs NOR by 4 pieces and relay that is activated by the transistor. Automatic water pump circuit requires +12 VDC voltage source and can be used to control the water pump is connected to AC power . Here is the complete series of pictures.
Automatic Water Pump Controller Circuit Diagram
working principle series of automatic water pump controller above is. At the time the water level is below both sensors, the output IC1C (pin 10) will be LOW, Kemudin when the water began to touch the lower level sensor, the output IC1C (pin10) remains LOW until the water touches the sensor level above, then the output IC1C (pin 10) going HIGH and active relay through Q1 and turn on the water pump to meguras reservoir.
At the muli down and water level sensors for water untouched MKA IC1C output (pin 10) remains HIGH until the new water untouched semuasensor IC1C output (pin 10) LOW and water pump died. The series of automatic water pump controller is equipped with SW1 which serves to reverse the logic of drains (the output of IC1C) and the concept of water supplied (output dri IC1D).
When SW1 is connected to IC1D the water pump will turn on when the water does not touch all the sensors and will die when all the sensors tesentuh water. Automatic water pump controller can be used to fill or drain the water according to which mode is selected via SW1.
List Component Automatic Water Pump Controller
R1 = 15K
R2 = 15K
R3 = 10K
R4 = 1K
D1 = LED
D2 = 1N4148
Q1 = BC337
IC1 = 4001
SW = SPDT Switches
Relay RL1 = 12V
Wednesday, December 18, 2013
Video Amplifier
The video amplifier in the diagram is a well-known design. Simple, yet very useful, were it not for the ease with which the transistors can be damaged if the potentiometers (black level and signal amplitude) are in their extreme position. Fortunately, this can be obviated by the addition of two resistors. If in the diagram R3 and R4 were direct connections, as in the original design, and P1 were fully clockwise and P2 fully anticlockwise, such a large base current would flow through T1 that this transistor would give up the ghost.
Video Amplifier Circuit diagram:
Moreover, with the wiper of P2 at earth level, the base current of T2 would be dangerously high. Resistors R3 and R4 are sufficient protection against such mishaps, since they limit the base currents to a level of not more than 5 mA. Shunt capacitor C4 prevents R4 having an adverse effect on the amplification.
Author: L.A.M. Prins - Copyright: Elektor Electronics
Source : http://www.ecircuitslab.com/2011/06/video-amplifier-circuit-diagram.html
Tuesday, December 17, 2013
Car Bulb Power Flasher
Derived from the Two-wire Lamp Flasher design, hosted on RED Free Circuit Designs since 1999, this astonishingly simple circuit allows one or two powerful 12V 21W car bulbs to be driven in flashing mode by means of a power MosFet.
Devices of this kind are particularly suited for road, traffic and yard alerts and in all cases where mains supply is not available but a powerful flashing light is yet necessary.
Car Bulb Power Flasher Circuit Diagram
| Parts | Description |
| R1 | 6.8K |
| R2 | 220K |
| R3 | 22K |
| C1 | 100uF-25V |
| C2 | 10u-25V |
| D1 | 1N4002 |
| Q1 | BC557 |
| Q2 | IRF530 |
| LP1 | 12V-21W Car Filament Bulb (See Notes) |
| SW1 | SPST Switch (3 Amp minimum) |
- Flashing frequency can be varied within a limited range by changing C1 value.
- As high dc currents are involved, please use suitably sized cables for battery and bulb(s) connections.
Source : http://www.ecircuitslab.com/2011/06/car-bulb-power-flasher.html
Thursday, October 10, 2013
2004 Chevrolet Corvette Coupe 350 Wiring Diagram
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| 2004 Chevrolet Corvette Coupe 350 Wiring Diagram |
The Part of 2004 Chevrolet Corvette Coupe 350 Wiring Diagram:power distribution, fuse block, turn
signal, switch signal, ctrl module, panel cluster, power distribution schematic, multifunction turn signal lever, underhood fuse block, cruise control switch, powertrain control module, serial data, sedel data secondary, throttle actuator control module, instrument panel cluster, powertrain control module.
signal, switch signal, ctrl module, panel cluster, power distribution schematic, multifunction turn signal lever, underhood fuse block, cruise control switch, powertrain control module, serial data, sedel data secondary, throttle actuator control module, instrument panel cluster, powertrain control module.
Wednesday, October 9, 2013
Thrifty Voltage Regulator
One of the drawbacks of a three-pin voltage regulator is that the input voltage needs to be 2.5–3 V higher than the output voltage. This makes these integrated regulators unsuitable for battery power supplies. If, for instance, the output voltage is 5 V, a 9 V battery could be discharged to 7.5 V or thereabouts only. On top of this, most of these regulators draw a current of about 2 mA. Special low-drop versions sometimes offer a solution, but they are not ideal either. The regulator described here is rather thriftier: it draws a current of only 300 µA and the difference between its input and output is only 100–200 mV In the circuit diagram, T1 is arranged as a series regulator, which means that the difference between input voltage and output voltage is limited to the transistor’s saturation potential.
Therefore, a 9 V battery can be discharged to about 5 V, which is quite an improvement on the situation with an integrated regulator. Diodes D1-D2-D3, or a suitable zener diode (D4), in conjunction with R5 and P1, form a variable reference voltage source, which is used as the (output-dependent) base potential of T3. If the output voltage drops below a desired level, the base potential of T3 also drops. The transistor then conducts less hard and its collector voltage rises. The base voltage of T2 also rises, so that T1 is driven harder. This results in the near-instantaneous restoration of the output voltage.
The design of the reference voltage source is clearly of paramount importance. The current through the LEDs or the zener diode is of the order of only 100 µA. This means that thedrop across a 5.1 V zener diode is only 4.3 V and across each LED, only about 1.43 V. For a wanted output voltage of 4.8 V, the three LEDs proved very effective, whereas the zener did not. It may well be necessary, if a zener diode is used, to try one rated at 4.7 V. If, however, an output voltage of 5 V is wanted, it will be necessary to carefully select a zener diode. When the battery voltage has dropped to a level where it is only marginally higher than the wanted output voltage, T1 and T2 conduct hard.
A further drop in the battery voltage will cause the collector potential of T2 to drop rapidly to 0 V, since T2 tries to make T1 conduct hard. The large drop in the collector potential of T2 may be used to drive a BATT-LOW indicator. This may be done in three ways as shown in Figure 2. When network a is connected between terminals A and B, transistor T4 will normally be held cut off by divider R6-R7a. If then the voltage at B drops suddenly, T4 conducts, where-upon D5 indicates that the battery is nearly flat. The network in b is similar to that in a, but is intended for a liquid-crystal display of BATT-LOW.
The collector of T4 is linked to the IC that drives the decimal point and the BAT-LOW segment of the display. Network c may be used if there is an unused inverter or gate in the circuit to be powered. The high value of resistor R7b prevents the internal protection diodes of the IC being damaged. When the regulator has been built, connect it to a variable power supply via a multimeter set to the mA range and set P1 roughly at its mid-position. Turn P1 slowly until the desired output voltage is obtained.
If with an output voltage of 4.8 V the regulator draws a current of more than 250–300 µA, the three LEDs or zener diode must be replaced. The regulator can provide a current of up to about 25 mA. With a fresh 9 V battery, the dissipation of T1 does not exceed 100 mW. If the input voltage is higher, it may be necessary to mount the transistor on a suitable heat sink or replace it by a power transistor, for instance, a Type BD138.
Read More..
Therefore, a 9 V battery can be discharged to about 5 V, which is quite an improvement on the situation with an integrated regulator. Diodes D1-D2-D3, or a suitable zener diode (D4), in conjunction with R5 and P1, form a variable reference voltage source, which is used as the (output-dependent) base potential of T3. If the output voltage drops below a desired level, the base potential of T3 also drops. The transistor then conducts less hard and its collector voltage rises. The base voltage of T2 also rises, so that T1 is driven harder. This results in the near-instantaneous restoration of the output voltage.The design of the reference voltage source is clearly of paramount importance. The current through the LEDs or the zener diode is of the order of only 100 µA. This means that thedrop across a 5.1 V zener diode is only 4.3 V and across each LED, only about 1.43 V. For a wanted output voltage of 4.8 V, the three LEDs proved very effective, whereas the zener did not. It may well be necessary, if a zener diode is used, to try one rated at 4.7 V. If, however, an output voltage of 5 V is wanted, it will be necessary to carefully select a zener diode. When the battery voltage has dropped to a level where it is only marginally higher than the wanted output voltage, T1 and T2 conduct hard.
A further drop in the battery voltage will cause the collector potential of T2 to drop rapidly to 0 V, since T2 tries to make T1 conduct hard. The large drop in the collector potential of T2 may be used to drive a BATT-LOW indicator. This may be done in three ways as shown in Figure 2. When network a is connected between terminals A and B, transistor T4 will normally be held cut off by divider R6-R7a. If then the voltage at B drops suddenly, T4 conducts, where-upon D5 indicates that the battery is nearly flat. The network in b is similar to that in a, but is intended for a liquid-crystal display of BATT-LOW.
The collector of T4 is linked to the IC that drives the decimal point and the BAT-LOW segment of the display. Network c may be used if there is an unused inverter or gate in the circuit to be powered. The high value of resistor R7b prevents the internal protection diodes of the IC being damaged. When the regulator has been built, connect it to a variable power supply via a multimeter set to the mA range and set P1 roughly at its mid-position. Turn P1 slowly until the desired output voltage is obtained.If with an output voltage of 4.8 V the regulator draws a current of more than 250–300 µA, the three LEDs or zener diode must be replaced. The regulator can provide a current of up to about 25 mA. With a fresh 9 V battery, the dissipation of T1 does not exceed 100 mW. If the input voltage is higher, it may be necessary to mount the transistor on a suitable heat sink or replace it by a power transistor, for instance, a Type BD138.
Tuesday, October 8, 2013
Dual 20 Watt Audio Power Amplifier
Overture Audio Power Amplifier Series Dual 20-Watt Audio Power Amplifier with Mute and Standby Modes
The LM1876 is a stereo audio amplifier capable of delivering typically 20W per channel of continuous average output power into a 4
Each amplifier has an independent smooth transition fade-in/out mute and a power conserving standby mode which can be controlled by external logic.
The performance of the LM1876, utilizing its Self Peak Instantaneous Temperature (°Ke) (SPiKe™) protection circuitry, places it in a class above discrete and hybrid amplifiers by providing an inherently, dynamically protected Safe Operating Area (SOA). SPiKe protection means that these parts are safeguarded at the output against overvoltage, undervoltage, overloads, including thermal runaway and instantaneous temperature peaks.
Circuit Diagram
Dual 20-Watt Audio Power Amplifier Circuit Diagram
| Key Specification |
| THD+N at 1kHz at 2 x 15W continuous average | |
| output power into 4 or 8: | 0.1% (max) |
| THD+N at 1kHz at continuous average | |
| output power of 2 x 20W into 8: | 0.009% (typ) |
| Standby current: | 4.2mA (typ) |
Monday, October 7, 2013
VGA to BNC Adapter Converter
There are monitors which only have three BNC inputs and which use composite synchronization (‘sync on green’). This circuit has been designed with these types of monitor in mind. As can be seen, the circuit has been kept very simple, but it still gives a reasonable performance. The principle of operation is very straightforward. The RGB signals from the VGA connector are fed to three BNC connectors via AC-coupling capacitors. These have been added to stop any direct current from entering the VGA card. A pull-up resistor on the green output provides a DC offset, while a transistor (a BS170 MOSFET) can switch this output to ground. It is possible to get synchronisation problems when the display is extremely bright, with a maximum green component.
In this case the value of R2 should be reduced a little, but this has the side effect that the brightness noticeably decreases and the load on the graphics card increases. To keep the colour balance the same, the resistors for the other two colors (R1 en R3) have to be changed to the same value as R2. An EXOR gate from IC1 (74HC86) combines the separate V-sync and H-sync signals into a composite sync signal. Since the sync in DOS-modes is often inverted compared to the modes commonly used by Windows, the output of IC1a is inverted by IC1b. JP1 can then by used to select the correct operating mode. This jumper can be replaced by a small two-way switch, if required.
This switch should be mounted directly onto the PCB, as any connecting wires will cause a lot of interference. The PCB has been kept as compact as possible, so the circuit can be mounted in a small metal (earthed!) enclosure. With a monitor connected the current consumption will be in the region of 30 mA. A 78L05 voltage regulator provides a stable 5 V, making it possible to use any type of mains adapter, as long as it supplies at least 9 V. Diode D2 provides protection against a reverse polarity. LED D1 indicates when the supply is present. The circuit should be powered up before connecting it to an active VGA output, as otherwise the sync signals will feed the circuit via the internal protection diodes of IC1, which can be noticed by a dimly lit LED. This is something best avoided.
Resistors:
R1,R2,R3 = 470Ω
R4 = 100Ω
R5 = 3kΩ3
Capacitors:
C1,C3,C5 = 47µF 25V radial
C2,C4,C6,C7,C10 = 100nF ceramic
C8 = 4µF7 63V radial
C9 = 100µF 25V radial
Semiconductors:
D1 = LED, high-efficiency
D2 = 1N4002
T1 = BS170
IC1 = 74HC86
IC2 = 78L05
Miscellaneous:
JP1 = 3-way pinheader with jumper
K1 = 15-way VGA socket (female), PCB mount (angled pins)
K2,K3,K4 = BNC socket (female), PCB mount, 75Ω
Read More..
In this case the value of R2 should be reduced a little, but this has the side effect that the brightness noticeably decreases and the load on the graphics card increases. To keep the colour balance the same, the resistors for the other two colors (R1 en R3) have to be changed to the same value as R2. An EXOR gate from IC1 (74HC86) combines the separate V-sync and H-sync signals into a composite sync signal. Since the sync in DOS-modes is often inverted compared to the modes commonly used by Windows, the output of IC1a is inverted by IC1b. JP1 can then by used to select the correct operating mode. This jumper can be replaced by a small two-way switch, if required.
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This switch should be mounted directly onto the PCB, as any connecting wires will cause a lot of interference. The PCB has been kept as compact as possible, so the circuit can be mounted in a small metal (earthed!) enclosure. With a monitor connected the current consumption will be in the region of 30 mA. A 78L05 voltage regulator provides a stable 5 V, making it possible to use any type of mains adapter, as long as it supplies at least 9 V. Diode D2 provides protection against a reverse polarity. LED D1 indicates when the supply is present. The circuit should be powered up before connecting it to an active VGA output, as otherwise the sync signals will feed the circuit via the internal protection diodes of IC1, which can be noticed by a dimly lit LED. This is something best avoided.
Resistors:
R1,R2,R3 = 470Ω
R4 = 100Ω
R5 = 3kΩ3
Capacitors:
C1,C3,C5 = 47µF 25V radial
C2,C4,C6,C7,C10 = 100nF ceramic
C8 = 4µF7 63V radial
C9 = 100µF 25V radial
Semiconductors:
D1 = LED, high-efficiency
D2 = 1N4002
T1 = BS170
IC1 = 74HC86
IC2 = 78L05
Miscellaneous:
JP1 = 3-way pinheader with jumper
K1 = 15-way VGA socket (female), PCB mount (angled pins)
K2,K3,K4 = BNC socket (female), PCB mount, 75Ω
Sunday, October 6, 2013
Mini Audio Signal Generator
A small audio test generator is very useful for quickly tracing a signal through an audio unit. Its main purpose is speed rather than refinement. A single sine-wave signal of about 1 kHz is normally all that is needed: distortion is not terribly important. It is, however, important that the unit does not draw too high a current. The generator described meets these modest requirements. It uses standard components, produces a signal of 899Hz at an output level of 1V r.m.s. and draws a current of only 20µA. In theory, the low current drain would give a 9 V battery a life of 25,000 hours. The circuit is a traditional Wien bridge oscillator based on a Type TLC271 op amp. The frequency determining bridge is formed by C1, C2 and R1–R4. The two inputs of the op amp are held at half the supply voltage by dividers R3-R4 and R5-R6 respectively.
Resistors R5 and R6 also form part of the feedback loop. The amplification is set to about ´3 with P1. Diodes D1 and D2 are peak limiters. Since the limiting is based on the non-linearity of the diodes, there is a certain amount of distortion. At the nominal output voltage of 1 V r.m.s., the distortion is about 10%. This is, however, of no consequence in fast tests. Nevertheless, if 10% is considered too high, it may be improved appreciably by linking pin 8 of IC1 to ground. This increases the current drain of the circuit to 640 µA, but the distortion is down to 0.7%, provided the circuit is adjusted properly. If a distortion meter or similar is not available, simply adjust the output to 1 V r.m.s. Since the distortion of the unit is not measured in hundredths of a per cent, C1 and C2 may be ceramic types without much detriment.
Read More..
Resistors R5 and R6 also form part of the feedback loop. The amplification is set to about ´3 with P1. Diodes D1 and D2 are peak limiters. Since the limiting is based on the non-linearity of the diodes, there is a certain amount of distortion. At the nominal output voltage of 1 V r.m.s., the distortion is about 10%. This is, however, of no consequence in fast tests. Nevertheless, if 10% is considered too high, it may be improved appreciably by linking pin 8 of IC1 to ground. This increases the current drain of the circuit to 640 µA, but the distortion is down to 0.7%, provided the circuit is adjusted properly. If a distortion meter or similar is not available, simply adjust the output to 1 V r.m.s. Since the distortion of the unit is not measured in hundredths of a per cent, C1 and C2 may be ceramic types without much detriment.
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