At the last Chester Machine tools sale week I purchased the head, column and motor of a Super Conquest Mill. On arriving home with my booty I discovered that the brush motor was 300w 240VDC.
I had presumed that it would be 24 or 36VDC and in that case it would have been quite easy to of purchased a commercial speed control unit.
On searching the internet I have not managed to find a circuit for a speed control for such a hight voltage motor.
The best things I have been told are to find a standard 36VDC speed control and change the Triacs, Thyristors for higher voltage components or use a inductive load dimmer to control a 240v 500w transformer with an 180v output connected to a full wave bridge rectifier.
There are possibly hundreds of way of doing this but I must stress I have never used Triacs, Thyristors and such although, I have built thing as divers as a Dolby stereo decoder to my latest project of a 5 keyboard digital pipe organ.
If anyone has a circuit for a control for a 240VDC 300w brush motor I would be very grateful it would save me the job of fitting a lower voltage motor and all the alterations to the head that would require.
James.