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  1. crutschow

    DC Relay pull-in voltage range 3v-12v help

    The page states: - Work voltage: DC 3V/3.3V, so don't see how it would work from 12V.
  2. crutschow

    Audio Amplifier in Common Emitter Configuration

    Any limits on how long the battery should last? Any other design requirements?
  3. crutschow

    Audio Amplifier in Common Emitter Configuration

    Why does that amp need to be that design, as it as it is very inefficient and will not generate much power into an 8 ohm speaker?
  4. crutschow

    Would like to know which wire to snip.... if I can even do that

    May I ask, why?
  5. crutschow

    Constant current source

    The are just to roll-off the feedback high-frequency response and improve the stability of the op amp feedback loop. The op amp negative feedback loop always tries to keep the voltage between its (+) and (-) inputs very close to 0V (typically a few mV or less), thus it adjusts the MOSFET gate...
  6. crutschow

    a transistor is a variable resistor

    I think that you are being too loose with the terminology. The usual meaning for a current (or voltage) controlled device is that a current or voltage is controlling separate, but not necessarily isolated parameter. I would call a thermistor a temperature controlled resistor (since it's not a...
  7. crutschow

    a transistor is a variable resistor

    Sorry, but I don't indulge in mind-altering substances, which you seem to. :rolleyes:
  8. crutschow

    a transistor is a variable resistor

    That's all such a load of muddled misinformation, I can't really make enough sense of it for a decent reply. A resistor is still a resistor whether there's voltage applied on not. Voltage does not "cancel" a resistance.
  9. crutschow

    a transistor is a variable resistor

    In spite of the name the BJT transistor is basically a current-controlled current-source, not a current-controlled resistance. It's difficult to make a controlled variable ohmic resistance for any significant voltage range. The FET linear ohmic region, for example, is usually only good for less...
  10. crutschow

    loudness question

    That is basically technical gibberish, so It's not possible to reply with any kind of coherent answer.
  11. crutschow

    240VDc supply

    Unless the power input to the radio is internally isolated, you need a supply isolated with a transformer from the mains. Otherwise be sure your accidental death insurance is in order. :eek:
  12. crutschow

    Would like to know which wire to snip.... if I can even do that

    Do you just not like the light or are you concerned about the power it consumes? If it's the power than the circuit inside providing the power to the light may use as much power as the light (typically a low-power LED), So if your reason to disconnect the light is to save power, you are likely...
  13. crutschow

    music amplifier with just resistors (falstad simulation.)

    What you are saying is not possible, not matter how you try to word it. But if you want to keep wasting your time on it, that's your prerogative.
  14. crutschow

    4 Position DC Switch (1 OFF and 3 ON Positions)

    A 4-position slide or rotary switch should work if it can handle the current.
  15. crutschow

    Transistor amplifier circuit

    Yes it is. And what collector-emitter voltage polarity is required for a PNP transistor to operate properly? The answer to that will show why it is upside down in your circuit.
  16. crutschow

    Simple delay on

    Where did you say you needed two outputs? In your first post you stated "when triggered by a 3v pulse, it waits for 3 seconds, triggers for 1 second".
  17. crutschow

    Simple delay on

    Yes. But then you need the magic of another 555 to get the 1 second output pulse after the delay.
  18. crutschow

    Simple delay on

    Here's the LTspice simulation of one circuit that uses one CD4093 chip to give the delay and one-shot, and one using two 555 chips: Take you pick--
  19. crutschow

    Simple delay on

    You would need two 555's. One for the delay and one for the pulse width.
  20. crutschow

    got osc with resistor and capacitor working in true falstad sim!!!

    Perhaps. But Falstad showed a circuit oscillating where the real circuit never would. A "old clunky sim" good simulator such as LTspice would likely not show that.
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