the load should befloating relative to the regulator arrangement, i assume you implied...
Make a test on a dummy load resistor before using it to power a circuit and it will show if working or needing something more
Hi Salas!
I get problem, the Led just dim with weak light, and I can not adjust output. Pls check the picture bellow and help me to fix it.
Thanks a lot !
I get problem, the Led just dim with weak light, and I can not adjust output. Pls check the picture bellow and help me to fix it.
Thanks a lot !
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To understand better, you made boards of your own and positive works but negative does not? If yes, and you are confident about parts orientations, see if Q2 Q3 have good Vbe about 0.6V. If yes, next see if M1 has good Vgs 4-6V, M2 good 3-4V. Last if there is oscillation on the output. Takes a scope for that.
I check Vgs on M1 IRF610/FPQ3N30 about 8.6V which is 7VAC transformer. So maybe M1 failed?!? And Could I replace with other IC? Pls recommend for part replace! Many thanks
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Looks failed. Compare this Vgs with IRF9610 M1's Vgs in the working positive polarity to confirm its wrong. Use another IRF610 for M1 negative.
Hello Salas,
I need to ask something. I'm planning to use UltraBiB for a 8V/35-50mA load. Input voltage will be 12V DC preregulated -LM7812- directly on the current limiter resistor -no rectifiers, no C1. First question is if there is anything wrong with that? The next question is how to trim the current limiter in order to minimize or even eliminate heatsink?
I need to ask something. I'm planning to use UltraBiB for a 8V/35-50mA load. Input voltage will be 12V DC preregulated -LM7812- directly on the current limiter resistor -no rectifiers, no C1. First question is if there is anything wrong with that? The next question is how to trim the current limiter in order to minimize or even eliminate heatsink?
Set 0.1A CCS for 0.4W @ 4V Vi-Vo M1 dissipation and it should take it sink-less. Don't skip some onboard C1. Even small. Else it can oscillate.
