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  1. Alec_t

    motor controller for electric bike project

    I expect you'll need more than that for an electric bike.
  2. Alec_t

    Overheat of electronic items

    Switch them off whenever possible.
  3. Alec_t

    How to maintAin electronic items?

    Keeping them switched off as much as possible will prolong the life of most elecronic gizmos. Keep them away from children. Do not immerse them (the gizmos, not the children) in liquids. Avoid using silicone-based polishes near electrical contacts. Replace the batteries at least a week before...
  4. Alec_t

    Need advise on charging Li-Ion battery

    The charger module datasheet should specify the input voltage range.
  5. Alec_t

    Eletronic horn on a toy car won't work.

    Looks like you've lost a connector spring.
  6. Alec_t

    Boost converter with no controller

    Are you referring to PWM of the switching FET, or PWM of the load current?
  7. Alec_t

    Boost converter with no controller

    With no feedback the output voltage will depend primarily on the mark/space ratio of the switching. For a reasonable range of loads, Vout = Vin x (switching-period)/(space-duration). The inductor limits the rate of rise and fall of current when the FET switches on and off. Assuming...
  8. Alec_t

    PCB Trace thickness/width

    Does this table help?
  9. Alec_t

    LED flashlights

    The flashlight could be relying on the internal resistance of the AAA cells to limit the current through the LEDs and drop the voltage down to ~3V, or whatever the forward voltage (Vf) of the LEDs is. The rechargeable battery would likely have a much lower internal resistance, so be prepared for...
  10. Alec_t

    18650 stays @ 4.15 volts

    :eek: Very likely, if the two were connected together without something to limit current. The 12V battery should survive ;).
  11. Alec_t

    Please help me with a simple circuit

    Why do you have two switches in series?
  12. Alec_t

    Why won't my TI CD4098B multivibrator give me a pulse

    That looks promising. Alternatively, just increase the value of the emitter resistor from 10k to, say, 100k.
  13. Alec_t

    Why won't my TI CD4098B multivibrator give me a pulse

    In your modified circuit the photo-sensor will have to produce about 250uA in order to bring the chip out of the reset state. Can it manage that much current?
  14. Alec_t

    Op Amp Circuit Noise

    The supply for opamps B and C won't be constant if the current they draw from it varies with input signal amplitude.
  15. Alec_t

    Optocoupler delay off MOSFET solenoid

    The circuit in post #14 is worth a try, but put the 10k in series with the trimmer instead of in parallel. Without the 10k in series you could have quite high current through the trimmer if it were set to near-zero Ohms inadvertently. With the 10k in parallel you are shunting the trimmer and...
  16. Alec_t

    Need to build an interface between an audiometer and a set of LED lights

    They are indeed for LTspice. I've no idea whether they can be imported into Multisim. Somehow i doubt it.
  17. Alec_t

    Need to build an interface between an audiometer and a set of LED lights

    Yes. Here's a zip of the latest versions of my 3914 and 3915 models, together with some test jigs.
  18. Alec_t

    5Volts Signal to 60V

    Not quite. You forgot the collector load resistor.
  19. Alec_t

    Optocoupler delay off MOSFET solenoid

    Yes, that's what I suggested. But see Hop's post above.
  20. Alec_t

    Trying to Attach Momentary Push Buttons (Rocker-Type) to a circuit board with Silicone Buttons.???

    It looks like the +ve leg of C21 is common to at least two of the buttons. That saves one solder joint ;).
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