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  1. CDRIVE

    Getting more gain from 5532 op amp?

    Yes, that's the general idea. Chris
  2. CDRIVE

    Help needed and appreciated Battery powered heat source

    Dave, that's a shocker! Are you saying they're not commercially made? Chris
  3. CDRIVE

    Electric/Battery Metronome

    Some interesting metronome history.. http://www.franzmfg.com/history.htm Chris
  4. CDRIVE

    How to increase 555 Timer Frequency

    Ha, in that case he might as well model the wire, component leads, battery contacts and PCB traces. Did I miss anything? :D Chris
  5. CDRIVE

    Pulse Train Detection

    What's the PhotoDiode part number? Chris
  6. CDRIVE

    Getting more gain from 5532 op amp?

    Why don't you use a switch to select the feedback resistor (Rf)? This way you can have two gain positions to handle either keyboard. The other option would be two inputs with a different value of Rin connected to each input jack. Chris
  7. CDRIVE

    Help needed and appreciated Battery powered heat source

    I'm sure that something is already commercially made and I don't think you can make one cheaper. Chris
  8. CDRIVE

    How to increase 555 Timer Frequency

    In your circuit if you want to maintain duty cycle you have to either change the value of C3 or change R3. R4 with like values or a ganged pot. By the way, what's the purpose of R2 (50uΩ)??? Chris
  9. CDRIVE

    Make triangular wave using 555 timer

    Hey Dave, I looked at your schematic, then your statement and thought .. "Shouldn't that be the first and second OpAmp forms the Osc but the second OpAmp alone forms the integrator"? ....Then I saw the positive feedback on OpAmp1 and thought .... "Gee! Sure glad I didn't post that"! :D :p...
  10. CDRIVE

    Simple Phototransistor switch circuit

    "I love it when a plan comes together" Quote: Hannibal Smith ;) You're welcome! Chris
  11. CDRIVE

    multiple leds off one resistor

    What color LEDs are they. Are they common 20mA LEDs? Chris
  12. CDRIVE

    Simple transistor circuit problem

    Just a note here. I wrote single FET in my first reply but I edited that, as it should have read BJT. I have no idea why I saw a FET in your schematic. Maybe because I party hearty on Saturdays. :D Chris
  13. CDRIVE

    Simple transistor circuit problem

    Because the Emitter of a BJT is ~0.7V lower than the Base. Since your BJT is a Darlington, which is two BJT's in a single package, it will be ~1.4V lower than the Base. Chris
  14. CDRIVE

    Simple transistor circuit problem

    You won't be able to latch it with a single BJT. Chris
  15. CDRIVE

    Bilge Pump + Solar/Wind + Battery = 24 Hour Functioning Water Pump

    This is usually the point where we get a link to a youtube video where a guy is powering his entire house, next door neighbor's too, with a palm sized home brew solar panel. :D Chris
  16. CDRIVE

    Help needed (Solar Lamp Circuit)

    Keep in mind that 10W is a max value and equates to only 833mA @ 12V. This has to be shared with a storage battery and two 7,2V battery packs. Chris
  17. CDRIVE

    S107 Helicopter Mod

    What's your charger specs? Chris
  18. CDRIVE

    S107 Helicopter Mod

    Pretty much yes to all except for 'C' which will depend on your charger.. Chris
  19. CDRIVE

    Help needed (Solar Lamp Circuit)

    I would think that a Constant Current Source (CCS) with full charge dropout or trickle charge mode would be in order. Considering that the cells will cycle every day full charge dropout should suffice. Chris
  20. CDRIVE

    Water Detector Circuit W/Relay

    That's problematic Bob. I don't see any way of controlling that. :( Ideas? Chris
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