Hope this is not in wrong section, sorry if it is.
Once I was been given an old Toshiba Boston stereo/gramo. It worked but was too big to keep so I only removed the whole turntable (without making notes).
Now I've decided to make a plinth and use it because it is a really nice turntable but have no idea how to connect the motor or what Voltage. Looks like Thorens but has no markings. I kind of hope someone might have an idea. If I can't get the motor going I've considered using cassette deck motor instead but it's probably not a good idea for what ever reason. I took pics of what I have, I'd appreciate any ideas.
Once I was been given an old Toshiba Boston stereo/gramo. It worked but was too big to keep so I only removed the whole turntable (without making notes).
Now I've decided to make a plinth and use it because it is a really nice turntable but have no idea how to connect the motor or what Voltage. Looks like Thorens but has no markings. I kind of hope someone might have an idea. If I can't get the motor going I've considered using cassette deck motor instead but it's probably not a good idea for what ever reason. I took pics of what I have, I'd appreciate any ideas.
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Is it this thing?
Toshiba Boston SP-790 Turntable Receiver Unit For Sale
You first need to check what kind of motor it is. Three kinds of motors are common:
Set the meter to AC voltage and give the motor shaft a few flicks. If the motor produces AC voltage, it is a synchronous AC motor. Now set the meter to DC and repeat. If it produces a DC voltage, it is a brushed DC motor. If it produces no voltage both in AC and DC setting, it is a shaded-pole AC motor. Take care however, some synchronous motors have a delicate ratchet mechanism built-in that prevents the motor from starting up in reverse direction. Check if the shaft rotates freely in the chosen direction before spinning it.
Shaded-pole motors are often open-frame type motors, which clearly show the windings and the rotor. So I'd consider this type to be the least likely when looking at your photos.
Now, it is a Japanese product, so it is probably made to run on both 50 and 60 Hz. That can be accommodated by all three motor types. In case of an AC motor, the motor may have two stators with a different number of poles, so the motor has a 50 hz and a 60 Hz stator winding. Both windings will behave the same in the above check. Or, the motor is a DC motor, in which case the other pair of wires may be a tacho winding, but since this is an early 70's turntable, I very much doubt that that is the case.
Toshiba Boston SP-790 Turntable Receiver Unit For Sale
You first need to check what kind of motor it is. Three kinds of motors are common:
- Synchronous AC motor
- Shaded pole AC motor
- Brushed DC motor
Set the meter to AC voltage and give the motor shaft a few flicks. If the motor produces AC voltage, it is a synchronous AC motor. Now set the meter to DC and repeat. If it produces a DC voltage, it is a brushed DC motor. If it produces no voltage both in AC and DC setting, it is a shaded-pole AC motor. Take care however, some synchronous motors have a delicate ratchet mechanism built-in that prevents the motor from starting up in reverse direction. Check if the shaft rotates freely in the chosen direction before spinning it.
Shaded-pole motors are often open-frame type motors, which clearly show the windings and the rotor. So I'd consider this type to be the least likely when looking at your photos.
Now, it is a Japanese product, so it is probably made to run on both 50 and 60 Hz. That can be accommodated by all three motor types. In case of an AC motor, the motor may have two stators with a different number of poles, so the motor has a 50 hz and a 60 Hz stator winding. Both windings will behave the same in the above check. Or, the motor is a DC motor, in which case the other pair of wires may be a tacho winding, but since this is an early 70's turntable, I very much doubt that that is the case.
Thanks, I'll check all that. It's got four wires so I'll start with the white. I took a better pic of it.
Stupid me not taking readings before removal, I didn't think I'll need it because I had a turntable.
Yes it is exactly that Boston. Description say it has 12 pole motor.
Stupid me not taking readings before removal, I didn't think I'll need it because I had a turntable.
Yes it is exactly that Boston. Description say it has 12 pole motor.
An externally hosted image should be here but it was not working when we last tested it.
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They're essentially two complete motors on the same shaft. You can also find this arrangement when two directions are required, for example in motors for lowering and raising blinds and shutters. It seems like a waste, but it makes switching between speeds (as seen here) or directions very easy.
In Japan, equipment must be able to use both 50 and 60 Hz mains, because they have both frequencies within the borders of the country. One motor is a 12 pole motor for use with 60 Hz, while the other one will be a 10 pole motor from use with 50 Hz. Both motors run at 300 RPM when fed with the correct frequency.
In Japan, equipment must be able to use both 50 and 60 Hz mains, because they have both frequencies within the borders of the country. One motor is a 12 pole motor for use with 60 Hz, while the other one will be a 10 pole motor from use with 50 Hz. Both motors run at 300 RPM when fed with the correct frequency.
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It looks like a 'standard' 2 phase motor, like the ones fitted to many turntables. One winding goes directly to the supply, the other via a phase shifting capacitor. Most of these motors are designed for ~120v and add a resistor when used with European 230v supplies.
If you login to Vinyl engine (free registration needed) you can download the manual for a similar turntable the 'Aurex Toshiba' TPS80 which shows how the motor is wired (p10).
If you login to Vinyl engine (free registration needed) you can download the manual for a similar turntable the 'Aurex Toshiba' TPS80 which shows how the motor is wired (p10).
I have had a couple of these two phase motors, and they all had the windings of both phases on one single stator, this motor clearly has two separate stators. I have never seen that arrangement, but it is entirely possible.
You can find the service manual here:
http://lecloudamoi.com/Toshiba/SR80.pdf
When looking at the exploded view, the motor looks the same as the motor you have, so it is indeed the two phase motor that Ralph said, not the stacked synchronous motor that I thought it was. You can change the working frequency by swapping the run capacitor and the pulley.
You can find the service manual here:
http://lecloudamoi.com/Toshiba/SR80.pdf
When looking at the exploded view, the motor looks the same as the motor you have, so it is indeed the two phase motor that Ralph said, not the stacked synchronous motor that I thought it was. You can change the working frequency by swapping the run capacitor and the pulley.
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