PR control box

[jseiler]

Any clue how much current an old PR driver can really source or a schematic of the driver card so I can figure it out. I'd like to hit somewhere around 2.5-3a to have enough uuuumpf to spin gearhead motors on a rack&pinion upgrade. (although I guess there's no law against running on the same rack...)

(I'll probably end up with a new control box in the end, but this one will be fun to play with in the meantime. This is nice because it runs on 110V. Does the new G4 or ascention run on 110 or are the 220 only?

[dirk]

Here's the spec on the driver chip
http://www.allegromicro.com/sf/97024/
Check your chip, but I think it's the SLA7026m.
I got the number off an old blown card and a piece was missing.
Dirk

[jseiler]

its the 7026. the spec says its good to 3 amps, surge even higher. A better heat sink would make sense and I'll have to do better than an unfiltered unfanned pc case. Can you tell from your card how the current adjust socketed resistor is connected to the 7026? Its probably a voltage divider with another resistor connected across the 28v drive voltage. I was also wondering if anyone had any experience running over 2a...some manufacturer's specs are a bit optimistic.

Do you run pk266's or other motors and are you using 680ohm and 28V?

John