:: ghetto PMOS current control
in
trying to re-purpose 2 of my used DPAK PMOS, i thought just
throw them into a sub circuit module to do some wide range variable
current control.
and
after some general "thermal camouflaging".The
controller in this test setup is powered from 20VDC. this test is
feeding a 3.3v. due to the biasing and help of a 10turn pot, it is
able to accurately reverse power the zener anywhere. the current is
so low (uA) the APPA meter is unable to read it proper
here in the
video, the APPA/UNI-T is swapped around. the UNI-T with uA scale is
able to measure the micro amperes.
it is interesting to see that with a 10 turn 1k bourns, the amount of
current is very easy to control. no kidding, controls down to 0.1uA
it seems, even with the uncertainty in the last digit of measurement
accuracy, we can see from the arbituary "movement" of the
current going thru from that start @ 0.1uA onwards. although it would
be tough to justify how i could use 0.1uA, still it goes up to 4.5A.
in the setup the temporary control module has 2 metal clothes pegs
clamping the brass tag to a heatsink. the aluminium clothes pegs are
a random find on taobao, it was a definite buy. 1) it can serve as
cable grounding retainers 2) temp heatsinks, 3) PCB work clamps ...
etc. unlike expensive sold as electrical accessory pegs or clamps or
croc clips, these are really cheap and useful.
Comments
Post a Comment
feel free to ask me anything