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Edison Universal Motor: Model 7 Shaver

Posted: Wed Nov 16, 2022 10:45 am
by flying500
Does anyone have technical specifications for the Edison Universal electric motor.
I would like to know what the power consumion is or what the power rating is.
I am in the UK and would like to find a suitable transformer to run the motor on our 240volt supply.
Thank You

Re: Edison Universal Motor: Model 7 Shaver

Posted: Wed Nov 16, 2022 11:10 am
by recordmaker
These motors normally have a specification plate.
They were all designed to run on the lowest common mains voltage used in the 1920s which typically have been about 60 V. under all circumstances these series-wound motors were used with a resistor in series to prevent a large starting current and also restricting excessive top speed when run unloaded mechanically.

In up grading a similar shaver I used a small 55v/ 55v transformer giving a center earthed 110v.
If you don't want to build your own equipment this can be obtained for site work tools and the smallest one obtainable will be more than big enough for the average 50W these use.
But you must include a resistor in series to drop about 40v at abut 0.5A it may be that the resistor in your shaver is still ok, but I am not clear if you have a UK adapted shaver (big dropper resistor) or an American one (smaller dropper resistance)

Re: Edison Universal Motor: Model 7 Shaver

Posted: Wed Nov 16, 2022 3:02 pm
by flying500
Thank you for your comments. I guess that you are a a bit more electrically minded than me.
I attach pictures of the 'Resistor' (which has continuity) and motor.
There is no spec plate on the motor just what is visible.
I am guessing that the setup is for 240v as I purchased the shaver in the UK.

Re: Edison Universal Motor: Model 7 Shaver

Posted: Wed Nov 16, 2022 3:51 pm
by JerryVan
The resistance appears to be adjustable. I would hook everything up, except for the motor itself. With the shaver plugged in and turned on, use a voltmeter to see what voltage you've got at the motor leads. I would hope to see 32V, which should be safe bet for that motor. If not at 32V, I would adjust the resistor, (with the power off!), until I see 32V, (when the power is on). Then, hook up the motor and see how, or if, it runs.

Needless to say, be careful!

Re: Edison Universal Motor: Model 7 Shaver

Posted: Thu Nov 17, 2022 7:24 am
by flying500
Thank you both.
Is there a wiring diagram available for the standard set up.
I am assuming that the Resistor and the motor would be in series to the ower switch on the live?