Question; does anybody know the type & value of the little red diode above D22 in the picture? I accidently broke it when removing all the white goo
Hi Pjotrovic! It's just a signal diode with IN4148 mark on it.Question; does anybody know the type & value of the little red diode above D22 in the picture? I accidently broke it when removing all the white goo
Peter
hello guys,
sorry for digging this thread, but i could do with some advice.
I am re-purposing a sub and i want to keep the PSU (the same this thread is about) but will get rid of the amp/DSP part. I figured out how to make the PSU work stand alone:
Just need to bypass transistor Q1, so that Q2 becomes conductive and supplies 12V to the PWM control IC. This is equivalent to supply 4.6V to the trigger input pin STB.
However, this is not sufficient for the PSU to work. It is necessary to connect +7V pin to -7V pin with a resistance no more than 2K in between. I don't know much about electronics and i don't understand why this is necessary, but it is. It is as if it is necessary to draw some current out of the 7V lines so that the auxiliar PSU can supply the 12V. As you approach to 2kOhm, the PSU starts to act erratically and the voltage output of the main PSU starts to decrease, and the lower the resistance the better it works, but i am afraid to go too low.
My question for you guys, how would you chose the right resistance value?
I understand that this part of the circuit is there only to supply the DSP board and supply 12VDC to the main PSU, so maybe it doesn't really matter and as soon as the main output reaches its maximum and the PSU stops to act erratically all is good, but i would like to hear the opinion of someone who understands how this works.
Thanks a lot for your comments and suggestions.
sorry for digging this thread, but i could do with some advice.
I am re-purposing a sub and i want to keep the PSU (the same this thread is about) but will get rid of the amp/DSP part. I figured out how to make the PSU work stand alone:
Just need to bypass transistor Q1, so that Q2 becomes conductive and supplies 12V to the PWM control IC. This is equivalent to supply 4.6V to the trigger input pin STB.
However, this is not sufficient for the PSU to work. It is necessary to connect +7V pin to -7V pin with a resistance no more than 2K in between. I don't know much about electronics and i don't understand why this is necessary, but it is. It is as if it is necessary to draw some current out of the 7V lines so that the auxiliar PSU can supply the 12V. As you approach to 2kOhm, the PSU starts to act erratically and the voltage output of the main PSU starts to decrease, and the lower the resistance the better it works, but i am afraid to go too low.
My question for you guys, how would you chose the right resistance value?
I understand that this part of the circuit is there only to supply the DSP board and supply 12VDC to the main PSU, so maybe it doesn't really matter and as soon as the main output reaches its maximum and the PSU stops to act erratically all is good, but i would like to hear the opinion of someone who understands how this works.
Thanks a lot for your comments and suggestions.