I traced the PS of my tt and it looks like the attached. As I know close to nothing about motors 🙂 could you please help me understand
- what is the purpose of the third cable (red) going to the motor
- is there any circuit to build for controlling the rpm?
thanks in advance
- what is the purpose of the third cable (red) going to the motor
- is there any circuit to build for controlling the rpm?
thanks in advance
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the motor is made by Papst and is connected with three wires.
I am not sure it would be okay to mention the tt maker as they also sell improved motors for the turntable
I am not sure it would be okay to mention the tt maker as they also sell improved motors for the turntable
It is a synchronous motor, thr red cable is for starting it is just a bipolar cap to the field winding.
The speed is dependent on the mains frequency and cannot be changed, Use different belt shaft diameter for different speeds.
The speed is dependent on the mains frequency and cannot be changed, Use different belt shaft diameter for different speeds.
thank you,
I need it for minor speed changes only and so as I understand a Variable Frequency Drive will be needed for altering the frequency fed to the motor.
Any hint for a suitable circuit? I assume it will be quite complex
I need it for minor speed changes only and so as I understand a Variable Frequency Drive will be needed for altering the frequency fed to the motor.
Any hint for a suitable circuit? I assume it will be quite complex
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Try “DIY 4 Phase Sinewave Generator for Turntable Motor Drive” in the analog source forum. Beautifully presented and nearly fool proof. Also several related threads for tachometer and use with three phase motors.
Hal
Hal
While that may look like an easy solution it might not be so simple. What is the frequency of the output? How stable/accurate is it? How pure is it (harmonic distortion?)
Pyramid’s projects are well thought out and presented. He has well laid out boards available through Osh Park and BOM in the first post. If you read through the posts you will see that he responds fairly quickly to questions and there are quite a few listers that will jump in with help when someone has a problem. This thread exemplifies what DIYAudio is about.
If you can handle a soldering iron you can build this project. If you can’t solder, you can learn the basics in an hour or two.
Pyramid’s projects are well thought out and presented. He has well laid out boards available through Osh Park and BOM in the first post. If you read through the posts you will see that he responds fairly quickly to questions and there are quite a few listers that will jump in with help when someone has a problem. This thread exemplifies what DIYAudio is about.
If you can handle a soldering iron you can build this project. If you can’t solder, you can learn the basics in an hour or two.
Surely there is no comparison between the two, it is just that I am looking for a quick and dirty solution 🙂
However I will also look into Pyramid's excellent project more thoroughly
However I will also look into Pyramid's excellent project more thoroughly
Software can alter the pitch by small amounts, if the signal is digital. If this is for musical purposes,
get the digital version of the music and you can do this. Of course, some turntables were designed to
be able to vary the speed by small increments, but not those with a line driven synchronous motor.
https://www.amazon.com/Audio-Technica-AT-LP120XUSB-Direct-Drive-Hi-Fidelity-Anti-Skate/dp/B07N3S4X3P
get the digital version of the music and you can do this. Of course, some turntables were designed to
be able to vary the speed by small increments, but not those with a line driven synchronous motor.
https://www.amazon.com/Audio-Technica-AT-LP120XUSB-Direct-Drive-Hi-Fidelity-Anti-Skate/dp/B07N3S4X3P
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