On 06/08/2020 12:07, Bert Coules wrote:
Dave Liquorice wrote:

I don't know if switching on and immediately rotating the control to say
quarter-full would overcome that.

Probably. Is the speed controller a PWM one or variable DC volts?

It's PWM.

which effectively IS variable DC volts, especially if run in series with
MUCH better than a potentiometer which wastes power and limits current
at low voltage settings

My original idea of a simple on-off switch between the PSU and the speed
controller, plus an overall on/off/safety cutout switch before the PSU
might perhaps provide an ideal all-round solution?

Apart from the difficulty in finding a suitably rated DC switch.
Can't remember if you stated a power for the motor...

It's 150W.Â* It's the standard electric scooter motor recommended for
this project.

Oh blimey. Its a crappy old speed 600 style motor then.

you can control that ever so easy from a DC source.

Its even easier to switch it with a semiconductor like a 2N3055.


A 24 V truck switches might be suitable or use a beefy 24 V truck
relay. Just seems a bit "messy" to mechanically switch the DC when
there is already something there doing it electronically.

If you mean the speed controller, I can wire everything up and try it.
I don't have a mains switch yet, apart, of course, from the switched
wall socket where the PSU is plugged but I can hardly use that as an
operational switch for the lathe, except for testing.

Thanks for the thoughts, Dave.

Bert



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