Can I tell voltage of motor ?

Thread Starter

Gary111

Joined Jan 22, 2020
7
I have a low voltage motor, the transformer seems to have failed, both this and motor are hard to remove from the casing. The motor is listed as 65w.
Is there any way of working out what voltage it is without (so I can use a different power supply ?) Without removing it?
Thanks
 

MaxHeadRoom

Joined Jul 18, 2013
20,471
It is a DC brushed motor, so you can back feed it (rotate it) and measure the DC voltage at a known RPM, the full voltage can then be extrapolated from the DC measured and max rpm of the motor.
Typically 2krpm to 2.5k rpm for that motor.
What is the application?
Max.
 

Thread Starter

Gary111

Joined Jan 22, 2020
7
It is a DC brushed motor, so you can back feed it (rotate it) and measure the DC voltage at a known RPM, the full voltage can then be extrapolated from the DC measured and max rpm of the motor.
Typically 2krpm to 2.5k rpm for that motor.
What is the application?
Max.
Thanks it’s a chocolate Fountain

Are these dc motors usually a common voltage ? Eg 12v , then maybe I could try a 12v 5a one that would give me 60w (bear the 65w it says on the outer case ?
Is that how it works?
Thanks

Is this a chiller or heater, with a thermostat??
Hi it’s a chocolate Fountain
 

BobaMosfet

Joined Jul 1, 2009
1,075
How did you confirm the problem is in the transformer?
I assume there is a bridge etc on the transformer secondary?
Max.
Ho
I have a low voltage motor, the transformer seems to have failed, both this and motor are hard to remove from the casing. The motor is listed as 65w.
Is there any way of working out what voltage it is without (so I can use a different power supply ?) Without removing it?
Thanks
You say 'low voltage motor' but don't tell us the voltage. How do you know it's 65W? If you know the wattage and the current, you can calculate the voltage.
 

Thread Starter

Gary111

Joined Jan 22, 2020
7
A computer power supply will work easily.
Thanks

Ho

You say 'low voltage motor' but don't tell us the voltage. How do you know it's 65W? If you know the wattage and the current, you can calculate the voltage.
It says the motor is 65w on the outer case, all I know is that the motor turned with a 7.5v power supply. hence thinking it must be low voltage.
I know neither current nor actual voltage.
Thanks
 

MaxHeadRoom

Joined Jul 18, 2013
20,471
12V would not damage it just a short test, you then tell by the RPM if it was significantly higher or lower.
There is no way to access the P.S.? If that's so, it sound like an odd creation!
Max.
 

Thread Starter

Gary111

Joined Jan 22, 2020
7
12V would not damage it just a short test, you then tell by the RPM if it was significantly higher or lower.
There is no way to access the P.S.? If that's so, it sound like an odd creation!
Max.
Thanks I’ll try, I’ve taken one apart before and they are very fiddly to get back due to the internal bolts position. You have to remove the motor to get to the power supply.Its a cheap Chinese design that failed quickly but no warranty.
Would the motor normally have the voltage stamped on it somewhere if I do decide to dismantle it ?
Thanks again for all your help
 

MaxHeadRoom

Joined Jul 18, 2013
20,471
In most case the motor manuf, attaches a plate, but I have seen Chinese versions that have none.
Did you notice or remember any details of what the P.S. consisted of?
Max.
 
Last edited:

Thread Starter

Gary111

Joined Jan 22, 2020
7
In most case the motor manuf, attaches a plate, but I have seen Chinese versions that hove none.
Did you notice or remember any details of what the P.S. consisted of?
Max.
Thanks no I can’t remember from last time, might see if I can get some info from the manufacturer,
Thanks again
 
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