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Can I run a 3V DC motor switched by a 12v relay? If not what do I need in the middle? Answered


NO the 12 volts refers to the operating voltage of the relay (coil) the contacts may be able to handle mains voltages. It is these contacts that act as switches for the motor.

You could get by with a reed relay and save some money.

thanks for your reply, if I do use a reed relay, are the 'rules' the same? Is it going to be a 12V reed relay for a 3v DC motor? Also, does it work the same way as a latching relay or just a normal one?
Thank you!

ICENG has done the work for you - You need to look up how relays work. A reed relay is a smaller cheaper version of the normal coil type relay. They can be operated by a wide range of voltages search for some information.

Note in ICENG diagram the 12 volts supply for the relay coil is separated totally from the motor supply. each can be anything you need.


6 years ago

Wiring for matisha
Description of circuit ;
12Volt Source could be a car battery or a Radio Shack 12VDC power supply.
K1 is a representation of a 12Volt relay.
S1 is a momentary electrical switch that turns on the relay.
Most 3Volt motors are DC motors
The AA or C or D dry cells add up to make 3VDC for your motor. . . . A


The motor stops when you take your finger off the button?

yes motor supply should be 3 volts relay actuation voltage 12 volts

So any lower than a 12v relay would not be enough to switch the 3v motor on?
I'm essentially about to order 2 sets of these (2 motors & 2 relays) and I was thinking if I can get a 3v relay for a 3v motor?
Thank you very much!