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Last Updated on: Thursday, April 07, 2016 02:04 PM

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Charge Pump Circuits
Dave's Charge Pump Circuits:
Page 1, Page 2, Page 3, Page 4

+5v Powered Charge Pump Battery Charger  -  The circuit below will trickle charge a four cell pack of AA or AAA NiMH batteries.  The circuit draws current from the +5v available a USB connection and pumps about 70ma of current into the battery. This should be enough current to fully charge a pack of . . . [Circuit by David Johnson P.E.,  02/07/10]


1 Watt Fluorescent Lamp Night Light  -  If you are tired of replacing small night light lamps, try this circuit. The line powered circuit uses a long life cold cathode fluorescent lamp. A simple charge pump technique runs the lamp without any transformer . . . [Circuit by David A. Johnson P.E.,  03/26/99]

125Khz LC Oscillator  -  This circuit adds more invertors in parallel to deliver more power. It is similar to CMOS INVERTERS FORM 125KHZ OSCILLATOR.  Please note that the values shown are for 125KHz. . . . [Circuit by Dave Johnson P.E.,  03/12/02]

 

125KHZ Medium Power Ocsillator  -  This circuit is similar to MEDIUM POWER 125KHZ OSCILLATOR but adds even more inverters in parallel to deliver yet more power.  The values shown are for 125KHz . . . [Hobby Circuit designed by David Johnson P.E.,  03/12/02]

 

125Khz Oscillator from CMOS Inverters  -  This circuit inverts the LC components so the inductor is grounded.  Two inverters are needed to produce the needed oscillation.  Again, the values shown set the frequency at 125KHz but can be changed to produce other frequencies . . . [Circuit by David Johnson P.E.,  03/12/02]

 

125khz Oscillator with Medium Power  -  This circuit adds even more inverters in parallel to deliver yet more power.  The values shown are for 125KHz . . . [Hobby Circuit designed by David A. Johnson P.E.,  03/12/02]

 

125Khz Ultra Pure Sine Wave Signal Source  -  For some RFID systems operating at 125KHz, a very low distortion signal source reference is needed.  The circuit shown on this page produces a 10-volt peak-to-peak signal into a 50-ohm load, with a distortion of only 0.01% . . . [Hobby Circuit designed by Dave Johnson P.E.,  02/11/02]

 

12v Touch Switch Exciter Circuit  -  This circuit is designed to generate a 20KHz pseudo sine wave signal that can power about 50 remote touch activated switch circuits.  It can support a cable length of about 2500 feet.  A typical remote switch circuit is also shown as well as a receiver circuit for those switches. . . . [Circuit by Dave Johnson P.E.,  02/10/02]

 

200Mhz-400Mhz Voltage Controlled Oscillator (VCO)  -  If you need a clean emitter coupled logic (ECL) type signal between 200MHz and 400MHz this circuit works fine. It uses four voltage-controlled capacitors to change the frequency . . . [Circuit by Dave Johnson P.E.,  03/19/99]

 

24v NiMH Battery Charger Using a 12v Solar Panel   -  A while back I received an email from a guy in the UK.  He wanted to use a small solar panel, designed to charge 12v lead acid batteries, but use it to charge a 24v battery pack.  His 24v battery pack used 20 AA size NiMH cells.  He went on to explain that his 20 cell NiMH battery pack was used very infrequently . . . [Hobby Circuit designed by Dave Johnson P.E.,  10/12/11]

 

300v Peak to Peak Signal Generator  -  This circuit converts a square wave signal to a +-150 volt output signal with fast 100nS rise and fall times . . . [Circuit by David A. Johnson P.E.,  06/03/00]

 

50/60Hz Sync Generator-Fully Isolated  -  This circuit will produce a single pulse at the zero voltage cross points of the power line voltage.  An opto-coupler provides a very safe 5KV isolation . . . [Circuit by Dave Johnson P.E.,  12/12/04]

 

60hz Clock Generator is Line Powered  -  This circuit is connected to the 120vac power line and transfers 60Hz clock pulses to a logic circuit. The optoisolator used provides 5000 volts of isolation between the power line and the logic side of the circuit . . . [Hobby Circuit designed by David A. Johnson P.E.,  02/23/99]


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