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  1. Alec_t

    Questions lithium polymer battery

    Read post #31 again. If still in doubt, contact the battery manufacturer.
  2. Alec_t

    Questions lithium polymer battery

    Dave has given you the answer in post #31.
  3. Alec_t

    Bistable Multivibrator

    That depends on the contactor's properties. If the contactor coil is designed to be powered by AC only, then using a diode would effectively reduce the impedance of the coil and could result in the coil burning out.
  4. Alec_t

    Weird burning plastic smell from the back of a LED TV?

    Welcome to EP! If the TV is still under warranty I'd get it replaced, rather than risk a fire.
  5. Alec_t

    How do I properly look at secondary ignition waveform with my RIGOL scope?

    I agree with Harald. Your trace looks to be in good agreement with the reference. What is the maximum voltage rating of your scope probe? I'm surprised it can cope with spark plug voltages.
  6. Alec_t

    IR IMAGING DEVICE on the cheap

    Have you considered a cheap-ish night-vision security camera? (Not sure if they block normal daylight.) These modules (or similar) are available with and without an IR filter. Perhaps use the difference between their outputs?
  7. Alec_t

    Looking for 60A 60V mosfet

    One thing you MUST add is a reverse-biased diode across the motor, otherwise the back-emf generated when the FET switches off will kill the FET.
  8. Alec_t

    Looking for 60A 60V mosfet

    In what way?
  9. Alec_t

    Two relays in series with flyback diode.

    Each relay could have its own flyback diode, if that's more convenient than lengthening wires.
  10. Alec_t

    What did Santa bring you?

    For testing the turkey temperature?
  11. Alec_t

    British Television?

    BBC channels don't have commercials but other channels do. BBC channels do however sometimes have trailers for BBC programmes, hence certain programmes may be shorter than the nominal 1 hour (or whatever).
  12. Alec_t

    Ripped off? We shall see!

    Hope it goes well. Keep us posted.
  13. Alec_t

    sunbeam electric blanket no heat

    It definitely needs fixing. With the insulation that badly damaged it's possible the internal wires have fractured.
  14. Alec_t

    How to determine current

    Is there a faint chance you have the actual spec of that LED? You really need to know its maximum current rating if you want to add a discrete current-limiting resistor. If the light is of oriental manufacture it may never have had one, the current being limited only by inherent resistance in...
  15. Alec_t

    Zoom GFX-5 guitar pedal - no power

    It's a typo for 'diodo' (= diode).
  16. Alec_t

    How to amplify 555 monostable 2 volts output signal(edge triggered)

    The 556 output will be about +11V. The FET source is at -10.8V. Hence Vgs will be about 21.8V, which exceeds the absolute maximum rating of the IRF740 and the IRF840. I smell smoke.
  17. Alec_t

    Why is the bottom right buttons on my calculator not working?

    That's good to hear.
  18. Alec_t

    Why is the bottom right buttons on my calculator not working?

    Buttons are usually in a scanned matrix. It is likely that all the affected buttons are in the same row (or column) of that matrix and perhaps the pcb track for that row is now open circuit. The pcb may have a microscopic crack caused by excessive pressure exerted by something in your bag...
  19. Alec_t

    How to amplify 555 monostable 2 volts output signal(edge triggered)

    Please post the schematic of your detector.
  20. Alec_t

    Mobile charger instead of Three AAA batteries

    Welcome to EP! I don't know what a 'messager' is, but if you mean 'massager' (i.e. a motor-driven device) then I'd say the answer is yes. My house doorbell was designed to be run from 3 AA cells, but it's been running happily from a USB charger for the last year or so.
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