On 26 July 2011 06:30, Dwayne Reid wrote: > At 10:01 AM 7/25/2011, Denny Esterline wrote: >>Ok, so I have product that has a small 12V motor running off a 48V bus. >> >>Now the face-palm moment - it needs more current (duh). > > Here's an easy solution: grab beefy plastic transistor that you can > easily heat-sink, connect a 33V or 36V zener from collector to > base. =A0Input (+) to collector, emitter goes to load. =A0Use a > darlington transistor if zener dissipation is a problem. > > No wasted power when load is off. > > Its pretty simple: two components. > > dwayne > > -- > Dwayne Reid =A0 > Trinity Electronics Systems Ltd =A0 =A0Edmonton, AB, CANADA > (780) 489-3199 voice =A0 =A0 =A0 =A0 =A0(780) 487-6397 fax > www.trinity-electronics.com > Custom Electronics Design and Manufacturing > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > Have you tried a large capacitor on your 12V rail to take care of the startup current? - Assuming your switching device will take the surge. (I'm assuming the 12V is available even with the motor off). RP --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .