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  1. Alec_t

    Volume knob, Roberts radio, intermittent failure

    I'd be tempted to run a fine drill through one of those hollow rivets, to get some switch cleaner inside.
  2. Alec_t

    Double Action switch repair

    Gold plating is worth a try. Gold plating solution is sold, but not cheap.
  3. Alec_t

    How do you connect all the voltages together into one?

    It doesn't work :(. If the maximum applied voltage in your circuit is 9V then unless your circuit includes an oscillator you won't get more than 9V out.
  4. Alec_t

    Substitute for MC14049 inverting hex buffer

    What output voltage and current do you want from the converter? Are you building the converter as a learning exercise or simply because you need one (it may be cheaper/quicker to buy a ready-made one)?
  5. Alec_t

    Heated Jacket not working

    The resistance of the heating element will be very low (probably <1Ω). Not all meters can measure that low a value accurately.
  6. Alec_t

    Can anyone recommend a simple linear VCO?

    If you are able to tweak those voltages then you could compensate for any non-linearity.
  7. Alec_t

    need help creating a circuit (struggling)

    Welcome to EP! Your project is doable but, for reliable operation, the circuit will need a LOT of components. The main problem is that there are many infra-red sources all around us, including sunlight, incandescent lamps, human/animal bodies, TV remotes etc; so the circuit has to discriminate...
  8. Alec_t

    Why is this LED not 20 Watts?

    They are not deceiving you with the 20W rating. For a LED rated at 38V (the driver maximum) drawing the rated 600mA the power would be 22.8W.
  9. Alec_t

    Can anyone recommend a simple linear VCO?

    I think you'll be hard pressed to manage even 1% linearity by analogue methods. Have you considered a digital approach?
  10. Alec_t

    Creating a Moisture percentage detector for soil

    If the highest voltage is 8V then you could use a 2:1 voltage divider and feed the output to an A/D input of a suitably programmed MCU driving the display.
  11. Alec_t

    Can anyone recommend a simple linear VCO?

    How much non-linearity can you tolerate? What voltage, frequency range, current capability?
  12. Alec_t

    How to remove solder from plated-through holes?

    Thanks. I'll bear all the suggestions in mind for next time I have to clear plated-through holes. In the meantime I cheated and soldered some wire stubs into the holes then attached a new IC to the stubs :D.
  13. Alec_t

    Substitute for MC14049 inverting hex buffer

    You say you are making a DC to DC converter. Are you aware that CMOS circuits have very limited current source/sink capability, so will need an output buffer stage to drive any significant load?
  14. Alec_t

    Creating a Moisture percentage detector for soil

    Welcome to EP! What sort of probe is connected to 'the terminals'? If your probe is the type which simply senses resistance, then the value measured will depend not only on the moisture content but also on the mineral content of the soil.
  15. Alec_t

    NiMH battery charging with a phone charger

    If you are trying to charge the batteries in series (not a good idea, unless you can be sure they remain balanced) the charger voltage will need to be at least 9.6V, so the 5V charger couldn't cope on its own. If the 5V charger is heating the batteries then either the batteries are dead or the...
  16. Alec_t

    I Want To Make A Device That Tells Me That Electricity Is Back

    One of these (or similar).
  17. Alec_t

    I Want To Make A Device That Tells Me That Electricity Is Back

    Mains-powered USB supply/charger with a buzzer attached? Just plug it in (or switch it on) when the mains power goes off.
  18. Alec_t

    Is it possible to design a 12 volt to 12 volt dc to dc converter

    Welcome to EP! Assuming you are talking about a switch-mode converter, the voltage across the inductor won't be zero (except at polarity reversal instants in the switching cycle of the converter. What are you doing that requires a 12VDC/12VDC converter?
  19. Alec_t

    New LTSPICE Version XVII

    Try this. Also, the LTspice Help gives guidance.
  20. Alec_t

    Op Amp 741

    Having now seen the meter pics it's clear that each responds to less than an octave frequency range. Therefore I think they could be driven with a square-wave signal, since harmonics of the fundamental frequency shouldn't affect them. As I said previously, a 100V-ish square-wave would be much...
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