The current in that design is very dependent on transistor parameters such as beta and Vbe that will change from part to part and with temperature. Adding emitter resistor(s) stabilizes things.
On Tue, May 14, 2013, at 10:39 PM, Przemek Klosowski wrote: > On Tue, May 14, 2013 at 3:08 PM, Gene Heskett <[email protected]> wrote: > > > > > So it looks like I need to design a 10 amp constant current load, switch > > mode of course. > > > > Perhaps something simpler? I have a sinking feeling that the electronics > wizards will soon hand me my head on the platter but I think that the > following circuit might work as a current load: it sets up a lousy voltage > reference and uses it to trickle enough current into the base of a > Darlington pair to drive the desired current through the load. > ------------------------------------------------------------------------------ -- John Kasunich [email protected] ------------------------------------------------------------------------------ AlienVault Unified Security Management (USM) platform delivers complete security visibility with the essential security capabilities. Easily and efficiently configure, manage, and operate all of your security controls from a single console and one unified framework. Download a free trial. http://p.sf.net/sfu/alienvault_d2d _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
