31-05-2011, 10:53 PM
Yes, thanks schottky.
As regards the cct., whenever I've come across a piece of kit such as this - and provided it isn't either too complicated or difficult to dismantle - I've usually traced out the cct. by hand. Often not the easiest thing to do & certainly time-consuming, but I like to be able to maintain my own test equipment (whenever possible).
Many years ago, when I used to repair SMPS PSUs (they were quite simple affairs in the early '80's), I did build myself an active dummy load using one beefy power transistor, a few seriously wattful Rs and some chunky heat-sinking: it worked well; knowing myself, I've archived the cct. somewhere. All of this is of particular interest to me at present, since I can feel the germ of an idea growing to make another active dummy load - or perhaps two - one for low voltages / high currents and another for high voltages / low currents.
Al.
As regards the cct., whenever I've come across a piece of kit such as this - and provided it isn't either too complicated or difficult to dismantle - I've usually traced out the cct. by hand. Often not the easiest thing to do & certainly time-consuming, but I like to be able to maintain my own test equipment (whenever possible).
Many years ago, when I used to repair SMPS PSUs (they were quite simple affairs in the early '80's), I did build myself an active dummy load using one beefy power transistor, a few seriously wattful Rs and some chunky heat-sinking: it worked well; knowing myself, I've archived the cct. somewhere. All of this is of particular interest to me at present, since I can feel the germ of an idea growing to make another active dummy load - or perhaps two - one for low voltages / high currents and another for high voltages / low currents.
Al.
