Alastair,
I see where the Digispeed is really designed for the KB drives so your translation will be:
KB to Parametrics
P1 becomes TB1-4 (0 Volts)
P2 becomes TB1-2 (0-10 volts input)
P3 becomes TB1-3 (+12.4 volts output)
I used TB1-4 instead of TB1-1 because there is a 100 ohm resistor between TB1-1 and common which is TB1-4. Also the manual says to use TB1-4 with external reference voltage. The only other issue here is that the Parametrics puts out 12.4 volts through an 820 ohm resistor to TB1-3. I would suggest putting a 4.7K (4K7 for you UK folks) 1/2 watt resistor between TB1-3 and TB1-4 to provide proper loading to get the supply back to about 10.5 volts. The problem with this is that switching to manual with a 5K pot is going to limit max speed in manual mode to about 88%. I don't really see any other problem as the wattage on the 820 ohm will be far less than it is rated for.
One further note. The start/stop logic is 6 volt DC, but the circuit common is tied to the positive DC bus and there is no isolation between the SCR bridge and the mains input. So be careful.
Let me see a little later what I can do about the manual. Our copy is a photocopy and there are 20+ 8.5x11" sheets, single sided. Perhaps I can take pictures and put them up on the web. Scanners are too slow.
Mike  |