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  1. crutschow

    Reverse Photoresistor for volume control when nearing

    For that you need a distance sensor, not a light sensor.
  2. crutschow

    hacking a smoke alarm

    Don't see that it's significantly more complicated than using an RF sniffer or hacking into the alarm.
  3. crutschow

    Off the Shelf Logic Gates?

    And here come your usual assortment of non-sequiturs.
  4. crutschow

    hacking a smoke alarm

    You said smoke detectors, so one way would be to add a microphone and amplifier to detect the alarm sound from the detectors. A simple analog band-pass filter would likely need to be added to suppress other than the alarm frequency (typically between 2kHz to 3.5kHz). Also have a delay in the...
  5. crutschow

    Off the Shelf Logic Gates?

    I would say 5 years is more than "a little late". :rolleyes:
  6. crutschow

    Trigger 12v relay with 3v source

    Here's the LTspice simulation of a circuit similar to what Bluejets suggested: It uses a Darlington output opto coupler (for isolation if the LED is low-side driven) with a high transfer gain, driving a MOSFET driver for the relay to minimize the current drain from the tach LED: It works because...
  7. crutschow

    Fuel level switch

    Then it's terrifying to imagine your psychedelic mind when it's not sober. :eek: Not surprising. I tend to make comments about other posters weird comments.
  8. crutschow

    Trigger 12v relay with 3v source

    Do you have access to what is driving the LED or just the LED leads? What powers the LED circuit?
  9. crutschow

    Fuel level switch

    You really need to sober up so we can understand what you are saying. :rolleyes:
  10. crutschow

    LM394 National Semiconductor 'supermatch' NPN pair

    Do you know how to connect to such a small, surface-mount device?
  11. crutschow

    LM394 National Semiconductor 'supermatch' NPN pair

    There are dual transistors available in a single package that should work better than two discrete transistors.
  12. crutschow

    Fuel level switch

    Or wait for the TS.
  13. crutschow

    Fuel level switch

    Well, you are reading way more into than I am.;)
  14. crutschow

    Fuel level switch

    A window comparator using comparators with open collector outputs, such as the LM339, can have the outputs connected together with one resistor pull-up to generate an output wired-AND function, for a simple steering mechanism (example below): So, within the window, both comparator outputs are...
  15. crutschow

    Fuel level switch

    Is the resistor by itself or is it connected to a fuel-level gauge or other connections? A window comparator should also work.
  16. crutschow

    Series Resistor in Place of Line Distribution Transformer

    It can be. But for the umpteenth time, you will lose most of the power in the resistors. Is that difficult to understand? :rolleyes:
  17. crutschow

    Series Resistor in Place of Line Distribution Transformer

    That calculates to only 30W into a 166 ohm impedance. The spec says the output impedance is 83 ohms for the 60W amp at 70V out. No, that will not be a valid test, since the resistor will give a much different line current for the same speaker power, than the transformer. You need to use the...
  18. crutschow

    Air conditioner remote control

    Given the proprietary nature of such a remote, I think it would be difficult to duplicate its signals. One possibility is to use WIFI controlled relays wired across the remote buttons to simulate the button presses.
  19. crutschow

    restoring old garage door opener-receiver/transmitter

    Do you have a meter to check the voltage across the relay contacts connected to the opener? It should drop to zero when the relay is activated.
  20. crutschow

    i am Dean Smuth

    If you don't know the answer to that, you've missed out on a lot.:D
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