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  1. CDRIVE

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

    I don't recall saying that or even hinting at it, but as Dave said, I too have never experienced significant mains hum on a Crystal set. Like Dave it's been a Long time ago though. Maybe we had less mains hum in the 50s. :D Chris
  2. CDRIVE

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

    Honestly I don't see how anyone can give you any, and I do mean any design advice without you supplying a cogent schematic. So far what we've seen is rather like trying to read Pigeon English. I mean those schematics are positively weird stuff. It's a toss-up as to which is more weird, this...
  3. CDRIVE

    Bottleneck 555's 0.2A Stuck project

    Good catch! That's a rather odd arrangement he has there. After all, the Discharge pin can only sink current. ;) Chris
  4. CDRIVE

    Car Speaker LEDS

    When we answer questions we first evaluate the perceived knowledge of the OP. When it appears that a detailed answer, that includes semiconductor theory and design, will only lead to more questions or not be understood anyway we reply like Steve did. We get all kinds of people that blow in and...
  5. CDRIVE

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

    After looking at those schematics (?) I think I need to wrap my head with duct tape to prevent it from exploding! :eek::eek: Chris
  6. CDRIVE

    Bottleneck 555's 0.2A Stuck project

    Ain't that the truth! I saved those in my FET folder. Chris"] Modern technology... amazing! Ain't that the truth! I saved those in my FET folder. Chris[/URL]
  7. CDRIVE

    kitchen timer to relay

    Is this mains lighting? 120VAC or 240VAC?
  8. CDRIVE

    Bottleneck 555's 0.2A Stuck project

    Your lower voltage limit may be an issue. I don't think I've seen any logic level FETs that can handle 10A. This doesn't mean they don't exist though. Chris
  9. CDRIVE

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

    Crystal sets are very basic, which is why there's always been a justified fascination with them. The RC filter is placed post detector. Post your schematic. Chris
  10. CDRIVE

    Car Speaker LEDS

    If you want the flash point adjustable you can to this. I'm assuming that your LED string is pulling under 100mA. Chris
  11. CDRIVE

    Car Speaker LEDS

    (1)I really don't see how the low side of your speakers could not be grounded. If they were floating above ground there would be no path to ground for your LED string. Todays autos have quite a bit of plastic in them. Are you sure you were connected to ground? (2) The Diode is absolutely...
  12. CDRIVE

    Op amplifier

    Sorry, but that's not true. A single ended OpAmp, NPN Collector and N-Ch FET Drain never go negative. The input side of the cap sees signal perturbations no lower than zero volts to some value approaching the positive rail. The output side of the capacitor delivers an AC voltage-current above...
  13. CDRIVE

    Car Speaker LEDS

    What values do you have? It's not a critical value Chris
  14. CDRIVE

    Car Speaker LEDS

    When circuits become complex running wire traces all over the schematic to indicate ground makes no sense and just confuses things. If you're going to pursue electronics as a hobby get used to seeing the GND symbol drawn many times in schematics. They're all the same electrical (node) point. ;)...
  15. CDRIVE

    Op amplifier

    It's easy to post attachments. We all do it all the time. Chris
  16. CDRIVE

    Car Speaker LEDS

    You can't drive the base of a transistor without some form of current limiting. Not doing so will eventually pop the Base - Emitter junction. It could also damage the output amp. The emitter is connected to chassis ground as shown. Chris Yes, that's 330 Ohms. The Diode is used to protect...
  17. CDRIVE

    Car Speaker LEDS

    I drew this up while Steve was posting. The value of R1 is nominal. That said, Steve's bridge rectifier suggestion would work fine too. Chris
  18. CDRIVE

    LM317L Voltage drop with load

    Yeah, I figured that it was just the schematic. ;) Chris.
  19. CDRIVE

    LM317L Voltage drop with load

    Along with what Harald said you should be aware that your caps don't appear to be grounded. In your schematic, that is. Your Cad program uses dots where connections are made. I know this because I see them in your schematic but both negative terminals of both caps appear to just rout over the...
  20. CDRIVE

    Op amplifier

    It's not there. Chris
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