Hi are there any other techniques a

[sunclipa]

Hi are there any other techniques apart from gears to slow down the rpm of a dc motor> this is to drive a small , low weight shutter . Many thanks in advance .

Tony

Sunclipa

 

[IRstuff]

You are supposedly ME, so you know that it's torque that drives your shutter, and a fast, tiny, motor, on its own doesn't have the torque; the datasheets already tell you that you need a pretty large, relatively speaking, gearhead to get the torque you claim you want.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[biff44]

yes. you can make a variable frequency motor drive, and pair it with a speed controllable motor.

such as:

https://www.groschopp.com/whitepaper/how-to-use-vfd-variable-frequency-drive/

in bigger applications, this is fairly common. i have a small milling machine that controls the spindle speed with a VFD controller

 

[Gr8blu]

sunclipa At any given moment, any motor operates under one of two conditions - constant torque, or constant (output) power.

DC motors achieve their constant torque range by varying the applied voltage (constant ratio between volt and rpm). Stationary field magnetic strength (i.e., field current) remains constant throughout. For the constant power range, the applied voltage is fixed (at the rated condition) and the field strength is reduced by lowering the field current.

AC motors work similarly. For constant torque, they generally vary the applied line voltage with frequency (a constant ratio). For variable torque, they hold the applied voltage constant and weaken the magnetic strength of the "field".

So
- DC motor. Reduce speed, maintain torque. = > Lower the voltage (linearly).
- AC motor. Reduce speed, maintain torque. = > Lower the voltage AND the frequency (linearly).

Converting energy to motion for more than half a century

 

[sunclipa]

Thats brilliant and most helpful. if only all the users of this site were as helpful a bit less grumpy

ps i labelled myself mechanical because there was no optical engineering option.

thanks again

Sunclipa

 

[Gr8blu]

sunclipa Most of the folks on this forum have backgrounds in a wide variety of electrical engineering "areas". Mine happens to be rotating machines (AC, DC, linear, permanent magnet, and reluctance), their controls, and their protections. As a side effect of my career, I also have a pretty good background in adjustable speed drives, power transmission and distribution, power generation, and of course all the industrial applications of that kind of equipment. Hence the tagline below

Converting energy to motion for more than half a century