Motor speed regulator IC

[doremi]

A friend brought a Philips 423 turn table which does not turn anymore.
It seems to me that the TDA1059 Motor speed regulator IC is defect. But to get this IC would cost about 30$.



Are there any more common replacment IC available?
In one thread LM317 was suggested, which differs slightly from the TDA1059 - see attachement (copyright Grundig?).



PS
TDA1151 is similar to TDA1059

 

[Mooly]

These IC's are a little like a voltage regulator except that they sense back EMF from the motor as a method of speed control vs loading. Cassette motors are often similar, sometimes using a two transistor discrete circuit.

The NTE1844 is another IC:

https://www.nteinc.com/specs/1800to1899/pdf/nte1844.pdf

You might be able to modify a board from an old cassette motor... the board is within the motor normally and there is a little hole on the back to adjust speed.

There is always a low value resistor on the board that is selected to match the DC motor resistance. It has to be correct for the circuit to maintain correct speed under different loadings. Get the value wrong and the motor will either speed up as you load it more or it will do the opposite and slow.

 

[doremi]

Thank you for your explanations Mooly.

An NTE1844 might be the easier way. Is the application/wiring same as for UTC1470 (cpr. UNISONIC TECHNOLOGIES)?

 

[Mooly]

I've not come across the UTC1470 before, however the pinouts look the same. You would have to try one and experiment with component values for getting the speed and speed vs load characteristic correct. Its only a few minutes work with it in front of you and wired to the motor.