Power source for both motor and circuit

I'm wondering if I can use the same power source to run a 3-6v mini gear motor and a circuit that runs on 4.5v (previously 3 x 1.5 batteries in series). If so, what power source would I be looking to get? Sorry VERY NOVICE HERE. Thanks

Sounds like you need a 4.5V power supply. Is there a possibility that the "4.5V" circuit will run on 5V? 5V supplies are very common. Some off-the-shelf 5V supplies might be adjustable down to 4.5V.

Any idea how much current the motor is going to draw when stalled?

Hi John,
thanks for the response. Here's the specs on the motor:

  • At 3VDC we measured 80mA @ 60 RPM no-load, and 0.5 Amps when stalled
  • At 4.5VDC we measured 90mA @ 90 RPM no-load, and 0.8 Amps when stalled
  • At 6VDC we measured 100mA @ 120 RPM no-load, and 1.0 Amps when stalled

I am less concerned about the motor as much as the circuit I have. It's one of those joke "laughing bag" novelties from the 60's/70's that I just bought new. It has 3, 1.5 volt batteries in series and I'm interested in have the motor and the circuit trigger with a motion sensor. I don't want to fry the laughing circuit so I was concerned about the simultaneous draw on both it and the motor simultaneously. The motor will run a clock that has little to no torque load...

I would be very surprised if using a 5V supply on the 4.5V device caused any damage. You could put a diode in series to drop the voltage about 0.6V to be extra careful.

You need a way to switch power since the output of a motion sensor is unlikely to be able to drive a motor. You could use an Arduino and a relay module with as many relays as you need. You can use the same 5V supply to power an Arduino UNO or Nano through the 5V pin.

Thanks John
I have an Arduino so I'll try that route...don't want to silence the laughing man....

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