Gene Heskett wrote: > > > And this of course would be ideal since the transistors don't normally have > a contact bounce. I wasn't aware you were making that Jon, thanks. > > With my first homemade servo amps, I did this with a couple of relays, and it worked. When I came up with my PWM servo amps, I wanted the same functionality and figured out how to do it electronically. It has to do 3 things at different times. Due to the large capacitors in the DC input of the servo amps, it can't just turn on hard and connect the amps to the bulk DC supply. So, it ramps up at a reasonable rate. Then it needs to have low resistance when on, so I use a 56 A transistor. Then, it has a modest transistor to connect the braking resistor when in the off state. See : <http://pico-systems.com/osc2.5/catalog/product_info.php?cPath=3&products_id=24> for a pic and other info.
Jon ------------------------------------------------------------------------------ Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before the end March 2013 and get the hardware for free! Learn more. http://p.sf.net/sfu/sophos-d2d-feb _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
