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  1. Alec_t

    Solenoid Help

    Another way of reducing/limiting the solenoid current, albeit more complicated than just a resistor, is PWM (pulse width modulation). This has the advantage of dissipating less power than simply a resistor.
  2. Alec_t

    Resistor wattage confusion

    So it is! Thanks.
  3. Alec_t

    BJT NPN + PNP to switch channel.

    What is the specification of the speakers? Are they powered or passive?
  4. Alec_t

    CD4017B has the jitters

    It looks correct, apart from the fact that there should be a reverse-biased diode (e.g a 1N4148) across the relay coil to protect the BC547 (and possibly the IC) from the back-emf voltage spike created when the coil is de-energised . Good luck.
  5. Alec_t

    Resistor wattage confusion

    There seems to be a connection from the OUT- rail to a tapping on R23. What's that all about?
  6. Alec_t

    BJT NPN + PNP to switch channel.

    Welcome to maker.pro. Please post a schematic of your setup.
  7. Alec_t

    Help with 74192

    Is the Qa output of the IC connected/soldered correctly and securely?
  8. Alec_t

    electronic Tesla valve (ETV)

    That is about the first statement you have made which is correct ! :) But if you want other people to show an interest in your circuit you should make it easy for them by drawing the circuit in a conventional way which can be readily understood without the need for mental gymnastics.
  9. Alec_t

    please i need a mentor to guide to learn how to make basic electronic circuits especially led emergency lights, mobile phone chargers, laptop chargers

    Welcome to maker.pro. As Crutschow says, start with basic electronics, such as learning the function of individual components. Chargers for laptops and phones are actually inside those devices and just need the appropriate power supply. You don't build the chargers themselves, and they are...
  10. Alec_t

    CD4017B has the jitters

    Without the flywheel diode (as per Danadak, post #3) the voltage spike when the relay coil switches off could have damaged the IC. You might also need a decoupling capacitor (several uF) connected directly between pins 8 and 16)
  11. Alec_t

    Searching for a potentiometer

    By " nothing" do you mean zero Ohms, or open circuit (infinite Ohms/OL)? What is the purpose of pin 4? Does it connect to the metalwork of the pot?
  12. Alec_t

    Searching for a potentiometer

    Welcome to maker.pro. From your measurements the pot is a 10k. What does it meaure between pins 1 and 4, and between pins 3 and 4?
  13. Alec_t

    The output of IR2104 is not square wave, Ho and Lo are not square wave. When Ho is high, then Lo is also high.

    What are your Vcc and Vin voltages for the IC?
  14. Alec_t

    Watts wrong?

    Had batteries been left in the meters all those years?
  15. Alec_t

    Controlling battery heat?

    Replace the incandescent bulbs with high efficiency LEDs. LEDs will require series resistors to limit current.
  16. Alec_t

    Cell Phone Charger

    Welcome to maker.pro. Some phones communicate with their charger to negotiate a charging current, so a plain battery bank may not suit all phones.
  17. Alec_t

    Looking for more help with my electronic ‘bagpipe’ project...

    No. Just remove/disconnect the diode, so that the chanter cap voltage isn't fed to the mixer. Don't bypass the diode. You don't want the drone circuit to affect the chanter cap voltage.
  18. Alec_t

    Looking for more help with my electronic ‘bagpipe’ project...

    I think that may be the source of your tremolo effect. The drone circuit will, via the mixer, source or sink some current from the chanter timing cap and hence modulate the chanter signal. Try disconnecting the diode from the timing cap and see if the tremolo disappears.
  19. Alec_t

    Simple MUX circuit

    If you are using the MM on a resistance range, don't forget the meter itself includes a current source to pass current through the load under test. Also, are the loads floating, or ground-referenced?
  20. Alec_t

    Simple MUX circuit

    Welcome to maker.pro. Can you post a sketch/schematic of your setup so that we have a better understanding of your project?
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