12-11-2013, 12:25 PM
Hi,
What a morning's fun I've just had rolling around uncomfortably under the hall floor in order to access the VFD.
I've checked and double checked the pot to VFD connections and they are definitely correct. I get a reading as you say Peter of 0V-10V between track ends and rotating the wiper also does as you say giving a smooth reading between both ends.
The wiper is connected to V1 the ends of the track to VR (+10V) & ACM.
I find the diagram below most confusing and I've spent a while reading the instruction manual but still don't grasp what the diagram is trying to tell me. If I read it correctly V1 is voltage controlled whereas A1 is current controlled?; what are the rectangle and circle on the diagram depicting?
Its interesting though that I've now got voltage readings between off and full speed as follows wiper to track ends; 9.93VDC Stop and 8.31VDC Full speed.
Between stop and full speed the pot gives speed control but only within this narrow voltage band?
I've used the same DMM for over twelve years so as soon as I started this morning it decided to wind the key up in my back by not giving voltage readings in fact with the lathe running at full speed the pot read dead on the DMM. Eventually after playing around the DMM did finally give a voltage reading so then I hooked the DMM up using quick hook up leads only for the DMM to die again so a trip up to the workshop was called for to collect my brand new DMM. The more this job plays up the more frustrated I'm becoming and I'm digging in because I'll not give in without a fight. So near and yet so far.
The new plastic gears have arrived this morning and look useful.
Kind regards, Col.
What a morning's fun I've just had rolling around uncomfortably under the hall floor in order to access the VFD.
I've checked and double checked the pot to VFD connections and they are definitely correct. I get a reading as you say Peter of 0V-10V between track ends and rotating the wiper also does as you say giving a smooth reading between both ends.
The wiper is connected to V1 the ends of the track to VR (+10V) & ACM.
I find the diagram below most confusing and I've spent a while reading the instruction manual but still don't grasp what the diagram is trying to tell me. If I read it correctly V1 is voltage controlled whereas A1 is current controlled?; what are the rectangle and circle on the diagram depicting?
Its interesting though that I've now got voltage readings between off and full speed as follows wiper to track ends; 9.93VDC Stop and 8.31VDC Full speed.
Between stop and full speed the pot gives speed control but only within this narrow voltage band?
I've used the same DMM for over twelve years so as soon as I started this morning it decided to wind the key up in my back by not giving voltage readings in fact with the lathe running at full speed the pot read dead on the DMM. Eventually after playing around the DMM did finally give a voltage reading so then I hooked the DMM up using quick hook up leads only for the DMM to die again so a trip up to the workshop was called for to collect my brand new DMM. The more this job plays up the more frustrated I'm becoming and I'm digging in because I'll not give in without a fight. So near and yet so far.
The new plastic gears have arrived this morning and look useful.
Kind regards, Col.
Happiness is a wreck of a cabinet to restore.
