Hi again all, I am still working on my vreg module design this afternoon- Some new reg's were delivered this morning so I have been trying them out, they are from TI and output 12V 500mA and 12V 1.5A. I have tried both in a test circuit and also tried another brand of similar spec- I am getting bad results when I test for current though- and am wondering if I did something wrong? They are putting out 12V dc just fine but the 500mA reg gives only ~200mA and the 1.5A only ~300mA !! The test circuit is typical- fed from 19vdc @ 2A or better, run through filter cap (470uF) after diode (4001), then direct into the reg. 0.1uF caps on both pins to gnd. Also a res/ LED indicator on the out tied to gnd.
When I test the current along various points, The LED cuts out. I am guessing that this is due to the meter testing/samples under a load? or is it a resistive thing? I think I may have been supposed to unconnect part of the circuit to take the test but cannot recall- plus it wouldn't make much sense cause what about if I wanted to test various portions of a circuit for current while under a load(like to make sure the circuit is running under loaded conditions)??
I suspect that I am just doing things wrong, but as far as the vreg output I just dunno, it is getting fed more than enough to run the reg,, and if there is that much a difference in the in to output then it must be very inefficient way to feed a circuit?? I'm disappointed. Tips, hackling welcomed, thanks in advance, jd
When I test the current along various points, The LED cuts out. I am guessing that this is due to the meter testing/samples under a load? or is it a resistive thing? I think I may have been supposed to unconnect part of the circuit to take the test but cannot recall- plus it wouldn't make much sense cause what about if I wanted to test various portions of a circuit for current while under a load(like to make sure the circuit is running under loaded conditions)??
I suspect that I am just doing things wrong, but as far as the vreg output I just dunno, it is getting fed more than enough to run the reg,, and if there is that much a difference in the in to output then it must be very inefficient way to feed a circuit?? I'm disappointed. Tips, hackling welcomed, thanks in advance, jd