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  1. CDRIVE

    Variable inductor instead of varible capacitor in FM crystal set

    Do you own a DMM? Most have a Capacitance function. Chris
  2. CDRIVE

    Variable inductor instead of varible capacitor in FM crystal set

    That's very good thinking. ;) Chris
  3. CDRIVE

    10 amp NPN Transistor switch circuit

    I guess he could also do this. C1 should prevent the FET's Cgs from slowing switching time. It doesn't compensate for contact bounce though. ;) Chris
  4. CDRIVE

    Default Wiring Multiple Lamps in Parallel to the Mains

    Oops! Chris
  5. CDRIVE

    Default Wiring Multiple Lamps in Parallel to the Mains

    Was I looking at the wrong bulb? I was commenting on the 12W LED bulb prominently featured on that page! Chris
  6. CDRIVE

    Default Wiring Multiple Lamps in Parallel to the Mains

    I'm assuming that you're located in the UK. These LED lamps are rated at 12 Watts each. That computes to 55mA at 220V. They're not designed to be wired in series. To find your total current multiply .055 x the number of bulbs. Your breaker size, wire size and type must meet your local...
  7. CDRIVE

    How to wire a relay TX2-L2-3V

    Did you check the coil with an Ohmmeter? Chris
  8. CDRIVE

    Battery backup for home project

    You didn't mention anything about alternative energy sources. If the mains go down where are we getting power from? Chris
  9. CDRIVE

    Fast blinking LED photocell?

    This circuit it based on a total LED current of 100mA. It may have to be modified if your current is high. Please post the current that your LED string draws. S1 is a DPDT switch to invert the logic as you requested. Chris
  10. CDRIVE

    Variable inductor instead of varible capacitor in FM crystal set

    Keep in mind that the aluminum foil on each plate must make physical contact with the nails. Chris
  11. CDRIVE

    CMOS Amplifier Design - tunable parameters

    This will not be a minor endeavor. Signals that low (1uV) will require a fully differential amplifier with excellent common mode rejection. I suggest that you Google "Differential Instrument Amplifier". Chris
  12. CDRIVE

    Variable inductor instead of varible capacitor in FM crystal set

    Dave will be elated that the "G" in your crystal radio designs will be abandoned. FYI, a layer of white paint will not decouple your body capacitance from your home made cap. I'm referring to your white nails of course. Chris
  13. CDRIVE

    long wire to transistor base

    Unfortunately the transistor and collector load is as yet unknown . I know It's assuming too much but if it's a small signal transistor I would expect it to be saturated or near it. With a 15V bias supply and 10K base resistor Ib= 1.4mA. It would take quite a bit of 60Hz hum to overcome this...
  14. CDRIVE

    Looking for resistor value and capacitor value for passive low pass filter remove RF

    Yeah, that works for me too. If you're going to make smoke it may as well be cheap smoke. Chris
  15. CDRIVE

    Variable inductor instead of varible capacitor in FM crystal set

    You can make an air variable cap from aluminum or tin can stock. The latter will take solder if needed. Chris
  16. CDRIVE

    long wire to transistor base

    Understood but I can't conceive how 6 feet of cable could manifest this. Maybe he's sitting in the field of a transmitter?? :confused: Chris
  17. CDRIVE

    Auto Window Up & Down

    You have to indicate what's OEM vs what you're adding. Currently, I can't tell the difference between the OEM door switches and yours. Darkening the lines on the print will help too. ;) Chris
  18. CDRIVE

    Bottleneck 555's 0.2A Stuck project

    Kris, my last link .. http://www.ebay.com/itm/N-Channel-Logic-Level-UltraFET-Power-MOSFET-75A-30V-/110635862022?pt=LH_DefaultDomain_2&hash=item19c2694806#ht_2773wt_917 is selling them for $1.00 + $8.00 for international shipping. There's no additional shipping charge if he orders 4 of them...
  19. CDRIVE

    Auto Window Up & Down

    Tired old eyes at this end and that print doesn't help. Chris
  20. CDRIVE

    Bottleneck 555's 0.2A Stuck project

    Check the data sheet to see what the Vgs(Th) is spec'd at. http://www.ebay.com/itm/N-Channel-Logic-Level-UltraFET-Power-MOSFET-75A-30V-/110635862022?pt=LH_DefaultDomain_2&hash=item19c2694806#ht_2773wt_917 Chris
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