Electrical – What kind of DC motor is this and what does the circuit do

brushless-dc-motorcircuit analysisdc motormotor

motor dismantled.DVD for scale

I've had this motor at least for 5 years (salvaged from something) and I remember it working then. However it doesn't work now (5 VDC mobile charger) and so I opened it up expecting to see just the split rings. But I was surprised to find this circuit built in it. Why does it need that circuit and what does it do?
The motor body says – (If the picture is not clear)
6JS E 06 R
2400N 6V

Link to a better quality picture
http://postimg.org/image/l4unckkin/

Best Answer

That looks like a DC motor of the type used in tape cassette players.

Why does it need that circuit and what does it do?

For music reproduction with accurate pitch constant motor speed is required. Achieving this in battery powered equipment requires addition of a voltage regulator or speed controller as DC motors' speed varies (nearly linearly) with voltage. The potentiometer in the motor allows the speed to be factory set.

I modified one such motor on a good tape deck, adding an external pot and switch to allow some pitch adjustment so that I didn't have to keep retuning my guitar between tracks / albums.

enter image description here

The TDA1151 seems to be one simple device intended for such applications.