Tiny motor needs lower voltages for lower speeds
Tiny motor needs lower voltages for lower speeds
(OP)
Guys and gals,
Original control of a two-speed motor (1/20th HP) was from a transformer with 120V primary and a double-tapped secondary at 85V (for high speed) and 75V (for low speed).
Transformer is no longer available, what would be the downside of using resistors to drop the voltage instead?
Original control of a two-speed motor (1/20th HP) was from a transformer with 120V primary and a double-tapped secondary at 85V (for high speed) and 75V (for low speed).
Transformer is no longer available, what would be the downside of using resistors to drop the voltage instead?
Best to you,
Goober Dave
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RE: Tiny motor needs lower voltages for lower speeds
Keith Cress
kcress - http://www.flaminsystems.com
RE: Tiny motor needs lower voltages for lower speeds
Best to you,
Goober Dave
Haven't see the forum policies? Do so now: Forum Policies
RE: Tiny motor needs lower voltages for lower speeds
Resistors = no isolation
Resistors = power dissapation
If you don't need isolation there are 1.75A small Variac Transformers that are panel mounted. You could use two and set them appropriately or use one and just set it to 75 or 85V as needed.
1.75A Variac
Keith Cress
kcress - http://www.flaminsystems.com
RE: Tiny motor needs lower voltages for lower speeds
Series capacitors do not produce EMI or dissipate heat. But tend to be somewhat expensive for reliable AC operation. Advantage: Can be installed without PCB. Just crimp then in series and tie them with nylon strips or whatever.
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: Tiny motor needs lower voltages for lower speeds
I'll follow up after the experiments. Those little variacs may be the key.
Dave
Best to you,
Goober Dave
Haven't see the forum policies? Do so now: Forum Policies
RE: Tiny motor needs lower voltages for lower speeds
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington
RE: Tiny motor needs lower voltages for lower speeds
RE: Tiny motor needs lower voltages for lower speeds
Could be useful if it is about single-phase fan motor:
http://winding.wixsite.com/design/single-post/2016/06/24/Multiple-Speed-SinglePhase-Fan-Motor
RE: Tiny motor needs lower voltages for lower speeds
A shaded pole motor produces the phase shift "inside" the motor (that's what the shaded/shorted pole does) so it can be very confusing to think single-phase cum capacitor and experiment with a shaded pole motor with a capacitor for voltage/speed adjustment..
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: Tiny motor needs lower voltages for lower speeds
RE: Tiny motor needs lower voltages for lower speeds
Best to you,
Goober Dave
Haven't see the forum policies? Do so now: Forum Policies