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  1. AnalogKid

    Oscillator or Not?

    Avid fan of rhetorical logic. https://en.wikipedia.org/wiki/List_of_fallacies#Formal_fallacies ak
  2. AnalogKid

    Delay off circuit

    Again, what is the current you are turning off after the delay? 20 mA, 1000 A, 1 uA...? An LM393 (actually, 1/2 of an LM393) is perfect for this, but it can't switch the output current directly. To select the pass device, got got gotta know the current. OK, re-read your last post. The...
  3. AnalogKid

    Oscillator or Not?

    Before 10K was 5K, and before 5K was 2K (the most popular version), but the actual number is 200. ak
  4. AnalogKid

    Oscillator or Not?

    So, the results already are biased. ak
  5. AnalogKid

    Oscillator or Not?

    Ah, someone (else) who quotes fallacies. Love it. ak
  6. AnalogKid

    Delay off circuit

    A 555 can do this. So can one opamp, or one comparator, or two transistors, or a logic gate. It also can be done with a counter or a microcontroller, but that is overly-complex for this task. Basically, the 12 V charges up a large capacitor through a large resistor. When the voltage hits a...
  7. AnalogKid

    programmable timed switch

    WHOA! You want to make a series of 5000 watt, 10 millisecond pulses, and you didn't mention that up front? Talk about burying the lead... ak
  8. AnalogKid

    Convert +12V DC to -30V DC

    You can search for a buck-boost or inverting-boost or inverting flyback schematic and get many images. But from the thread it sounds like that is not what you actually need. For your application circuit, which you still have not posted, what is the input signal voltage range from positive peak...
  9. AnalogKid

    Convert +12V DC to -30V DC

    What's the big deal? You do it all the time. ak
  10. AnalogKid

    programmable timed switch

    For 10 outputs, one approach is a CD4017 driving 10 PNP and 10 NPN switches, with a bunch of steering diodes assigning the switches to the proper outputs for the pattern. Basic stuff, not much to go wrong, but changing the pattern means significant rewiring. What voltage and what current? Or...
  11. AnalogKid

    programmable timed switch

    Is this for homework or a commercial product? ak
  12. AnalogKid

    Signal conditioning for 555 circuit

    Off my feed today, missed that. And at 12 V Vdd, the hysteresis thresholds are more than 3 V apart. So maybe an NPN saturated switch input stage instead of U1A. oops. ak
  13. AnalogKid

    Signal conditioning for 555 circuit

    A frequency-to-voltage converter - excellent! Alec wins, but here's my version, more of a digital domain solution. This one does not assume that the alarm and non-alarm pulse widths are different. ak
  14. AnalogKid

    Signal conditioning for 555 circuit

    This is very doable, but a bit more complex than a pair of 555's. Because the first pulse is used to enable a detection window for the second pulse, the detector has to not see the first enabling pulse as a trigger. Normally this would mean there has to be a true edge detector, an edge...
  15. AnalogKid

    Tv on a boat.

    What we have here is 'failure to communicate.' Strother Martin to Paul Newman With a high-power non-isolated boost converter as the power supply for a low-power load, turning off its power source is the direct cause of all of your problems. I recommend that you accept that. According to...
  16. AnalogKid

    Tv on a boat.

    The "not infrequent power cuts" are to the Samsung power supply that came with the TV, one designed to protect this TV from power dropouts. The DC/DC converter on the boat has no such pedigree. Since there are at least 5 different circuit topologies for such a converter, several of which have...
  17. AnalogKid

    Tv on a boat.

    Polarity?
  18. AnalogKid

    convert 110v dc to 24v dc

    Right-click on the image, save it to your computer, and upload it to the post as a file.
  19. AnalogKid

    Tv on a boat.

    Why? Why not turn the TV off the normal way, by pressing the power button on the remote? This maintains a small load on your power converter at all times, and could be critical in keeping things working correctly. What is the DC/DC boost converter you are using to turn 12 V into 14 V? ak
  20. AnalogKid

    Convert +12V DC to -30V DC

    opamp part number? Circuit schematic?
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