This may sound silly to most, however, it answers a million questions for me, so please have mercy on the down voting, thanks.

A simple example without specifics, when a battery and a DC motor are connected via +/-, the motor spins.

Theoretically, in my mind atleast, an AC-DC adapter(again without specifics) with the wire cut at the output end will have a positive and negative wire. If these were to be correctly connected to the same DC motor as before, the motor should also spin. Is this correct or am I missing a screw?

  • \$\begingroup\$ Generally, it should, yes. \$\endgroup\$ – Andy aka Feb 22 '18 at 20:44
  • 1
    \$\begingroup\$ Yes it will assuming it's the right voltages and can give enough current. I can't tell if you are missing a screw though! \$\endgroup\$ – Trevor_G Feb 22 '18 at 20:45
  • 1
    \$\begingroup\$ Normally yes but... Depends on the capabilities of the AC adapter, battery and motor. Motors are particularly nasty loads, they may take several times their rated current for a moment while starting. That can shut down the over-current protection in some AC/DC adapters, but others may be OK. \$\endgroup\$ – Brian Drummond Feb 22 '18 at 20:45
  • 2
    \$\begingroup\$ Not sure if you're missing a screw but there's a nut loose behind the keyboard here. \$\endgroup\$ – John D Feb 22 '18 at 20:52

Yes. Generally speaking, a DC motor spins when a DC voltage is applied to it. It may require that the polarity of the voltage be in one direction if the motor only spins in one direction, but it will spin. Batteries and AC/DC adapters both provide a DC voltage.

Now the specifics do matter. If you have a motor that wants to draw a lot of current, and a AC/DC adapter that cannot provide a lot of current, then you can run into issues.

  • \$\begingroup\$ Thanks guys. I thought this maybe the case, but didn't have the balls to test from the wall. I understand that the specifics do matter, however, I am already aware of what is required in that area, but appreciate it anyway. Again thanks all. \$\endgroup\$ – user4163554 Feb 22 '18 at 20:52
  • \$\begingroup\$ I will accept your answer.....once this timer has ended! \$\endgroup\$ – user4163554 Feb 22 '18 at 20:56
  • \$\begingroup\$ @user4163554 In general low voltage power from a DC wall adapter should be safe, unless you have a very cheap and shoddy wall adapter (such as a lot of knockoff Apple USB chargers) \$\endgroup\$ – immibis Feb 22 '18 at 22:05

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.