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What are the basics of power supply mechanics to voltage and RPM's in micro vibration motors? Answered

I'm trying to make several different versions of vibrating plush toys so I can find out what the ideal vibrating feeling will be for toddlers and babies. Too high an RPM can be scary to a little kid.

I'm a beginner with little/no knowledge of basic electronics, but a capable tinker and solderer. I'd like to understand the basic logic of power supplies to micro motors and how to arrange the basic wiring. I've seen lots of instructibles but I can't find a simple explanation of this kind of thing.

I've got a Radio Shack 3VDC vibe motor. no-load speed is 16K RPM. I tried wiring it to a two-AA battery enclosure (2x1.5V=3V?) and it wouldn't run. Touched leads to a 9V and it powered up but RPMs are way too high.

Some related questions:
1. Can you vary the voltage to a typical micro motor and get different RPM's?
2. What's no-load speed and do I need to worry about it?
3. What kind of switch can I use to power on/off
4. How do you tell what kind of battery config to use with a motor


I'm surprised that it didn't run on 3V. I suspect you'd have more success with a PWM power supply to it. Are you sure the 3V batteries were OK ?

OK I'm a bit of a heel! I thought my AA batteries were new but they're dead. Regardless of that though, can you tell me if it's possible to vary the speed of the motor with a pot, or would i have to use separate motors to achieve different RPMs?

Using a pot is a bad idea, but using an adjustable voltage regulator like an LM317 would be perfect.

There are thousands of circuits on the web for that.


Thanks for this advice. Very helpful. Here's my next question:

I'd like to repurpose a network of mini momentary closed switches I salvaged from a toy so that if any of the switches is depressed, it starts the vibration motor. What kind of circuit could accomplish that?

...and here's an even bigger aspect of my project that I presume I won't be able to accomplish without the help of an arduino: I'd like the vibration motor to run for 2 minutes after the last time one of the momentary closed switches is depressed.

Thanks for your time!

The wiring is simple, put them all in PARALLEL.

The timing, you can get a 555 timer to do the job for you.