Turntable - Reverse Motor

[Arsin225]

I know how to do this with a basic stamp to tell the motor to input the electricity backwards but I don't have one at my disposal, so how would I get my motor to reverse play?

I can get into the internals easy enough and I can find the electricity wires, but I just don't know what I would do once I un-soldered it. I remember double throw switches but I forgot how to operate one.

Anyone mind helping me out? Thanks

[directdriver]

I am also looking for a way to make the platter on my Technics SL-1200mk2 to go in reverse so I can turn it into a "direct-coupling" motor to rim drive another platter a la Teres Verus motor. Any idea anyone? I would appreciate the help.

[nimbus24]

Could turn it upside down that would do the job!!!
I have had a look at the circuit diagram for the control circuits for the driver coils. It could be done by reversing the rotation of the drives to the motor coils from the AN6675 drive IC. But then you would also need to reverse sense coils, it all gets very complicated!!

It is not the type of mod to undertake unless you are a competent electronis person the amount of switching required is not simple and any mistake would cause the control IC to die very quickly.

[johnf1]

It is a Very simple task. before I explain Hi there.
You will be able to reverse the motor or any motor, but there is a simple check before you do this, check to see what type of conacts internally if it is brushes, you must smooth the ragged edges before allowing the motor to reverse ye, just reverse the + and N - terminals and the motor will reverse at the same forward speed. only reverse the polariy exactly at the motor, you could do this by a double pole switch depending on application, hope this has'nt put a spanner in your plans.

[Steerpike]

The SL1200 used an electronically commutated 3 phase motor. No brushes in sight!
As Nimbus said, you have to swap the connections of two of the three drive coil phases.
Along with that, you'd have to switch the phase pickup coils that detect the phase rotation sequence.
It's not *difficult* but you have to understand how the DD motor works so you don't damage it.

Have you got the schematic (circuit diagram) ?

[directdriver]

I decided to give up on the Technics, they all have a tendency to rock back and forth. I have moved on to Pioneer turntables. Less torque but more reliable. I would like to know how to make the motor run in reverse on the PL-570. Schematics can be downloaded from Vinyl Engine.
http://www.vinylengine.com/library/pioneer/pl-570.shtml

Or PL-L1000
http://www.vinylengine.com/library/p...pl-l1000.shtml

Thanks for any help in advance!

[Steerpike]

On Assembly PWX 006, PL570

Swap pin 13/14 - drive to motor coil B/C

Swap pin 10/5 - Hall phase detection C+/B+
Swap pin 3/7 - Hall phase detection C-/B-

(If the motor does not run smoothly, restore the swapped connnection 13/14, and swap 12/13 instead. If that doesnt't work, restore 12/13 and swap 12/14. One of the 3 will work. The schematic doesn't show precisely the rotation sequence, so it has to be a guess.)

[directdriver]

Thank you for your help!

If I apply the same concept to the PL-L1000, a later model that has the FG frequency generator wires from the motor to the drive board, will it work as well?

Thanks again for the direction.

[Steerpike]

Yes, the FG is not involved in direction control - it doesnt need to be messed with.
The PL570 also uses an FG, associated with Q1 & Q2 and Q5 = PD100ia

[directdriver]

Thanks for the reply.

I was thinking about the "FG" from the motor typically feature in turntables of this era as pointed in the schematic of a Pioneer PL-500, that I don't see in the PL-570.