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  1. Alec_t

    Circuit Simulation of LTC3703

    What does your sim tell you? Compare the power provided by the supply to the power dissipated in the load.
  2. Alec_t

    How can I change in LTSpice 555timer frequency??

    Which Spice model of the 555 are you using? The default model that comes with LTspice is an idealised one, so will not give a true-to-life simulation result. Welcome to EP!
  3. Alec_t

    Circuit Simulation of LTC3703

    Yes, as far as the LED arrangement is concerned (though you might find the LED needs a higher value resistor if too bright). I haven't checked the rest of the circuit.
  4. Alec_t

    Circuit Simulation of LTC3703

    Where are you going to find one of those? Visible-light LEDs generally have a Vfwd of at least ~1.8V (depending on the light colour).
  5. Alec_t

    LDR/BC550 as switch - Darkness threshold.

    For animal or human building? Regardless, there will be safety issues to consider, to prevent damage/overload if the door is obstructed. How will your system cope with unwanted activation due to e.g clouds passing, insect on sensor, etc? Does your opener/closer include internal limit switches?
  6. Alec_t

    LTSpice simulation with laser source and APD

    Welcome to EP! It should be possible if you can get/make reliable Spice models of all the components. This article may be of help for modelling a laser diode.
  7. Alec_t

    LDR/BC550 as switch - Darkness threshold.

    What load will your relay switch? (You might not need a relay).
  8. Alec_t

    Testing Current of AC-to-DC converter module without load

    If your meter was switched to its current-measuring mode and you connected it directly to the power supply module then you created a short circuit (a massive load presented by the internal shunt resistor in the meter) across the supply. Either the meter or the module was going to let out the...
  9. Alec_t

    I would like to power a table radio with 12V DC instead of 110V AC

    You could use an analogue voltage regulator, or switch-mode DC-DC converter, to drop the car battery voltage (say12-15V) down to a fixed 9V to run the radio safely within its existing ratings. Such a DC-DC converter, if of low quality, might introduce undesirable noise though.
  10. Alec_t

    I would like to power a table radio with 12V DC instead of 110V AC

    The schematic for the power supply in the post #3 link shows a 9V battery. You would need to check that all components in the radio are rated to handle a minimum of 12V. You also might need to adjust transistor bias voltages at various points in the circuit to cope with raising the supply from...
  11. Alec_t

    LDR/BC550 as switch - Darkness threshold.

    Welcome to EP! A 50 Ohm relay isn't going to be 'low consumption' if energised for a long period. Have you considered using a latching relay? That requires a brief current pulse to switch it 'on' and a second brief current pulse (which might need to be of opposite polarity to the first one) to...
  12. Alec_t

    Diode help and general question

    Any diode will drop voltage, so you will have only 4.0V (for a normal silicon diode) or 4.4V (for a Schottky diode) after the diode. USB is rated at 5V. An 18650 lithium cell needs 4.2V for full charge. Welcome to EP!
  13. Alec_t

    Need help repairing Microwave oven

    Guys, the original post was Aug 2021. It's likely the issue has been resolved/abandoned.
  14. Alec_t

    Timing circuit using LM339

    U2A needs a pull-up resistor on its output. Welcome to AAC!
  15. Alec_t

    Faulty Electronics and Ethical Practices

    Most people just send it to landfill.
  16. Alec_t

    Liquid Volume Measuring Project

    For low flow rates, this article may give you some ideas.
  17. Alec_t

    Liquid Volume Measuring Project

    Welcome to EP! 1) What sort of volume? Micro-litres? Litres? Mega-litres? ......? 2) What sort of liquid? Water? Treacle? Corrosive? ...? 3) Over what temperature range? Edit: 4) Is the liquid flowing or stationary? 5) Is it in a regularly-shaped container (e.g. cylindrical) or not?
  18. Alec_t

    Audio spontaneously develops volume flutter at about 10 Hz

    Is your radio close to a road with passing traffic?
  19. Alec_t

    Audio spontaneously develops volume flutter at about 10 Hz

    Could be a motorboating problem due to a dodgy capacitor. Welcome to EP!
  20. Alec_t

    Tachometer

    The schematic in post #1 has an error. The wire from pin 2 should connect to both R2 and R3. (I assume the wire gap between R2 and R3 represents a bridge over the pin 2 wire).
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