Electronics > Projects, Designs, and Technical Stuff
I have a short ( i think) and don't know where to start
<< < (3/13) > >>
Hextejas:
Nick, as i follow your suggestion of putting a small DC voltage on U1, where do i put the other side of the DC voltage ? The ---- minus side of the 9V battery ?
As an aside, this is not my design. I am following anothers. Got it from here.
http://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886/#The-Final-Schematic
Hextejas:

--- Quote from: sokoloff on December 16, 2018, 02:52:10 pm ---A full wave bridge rectifier uses two diodes for each half (positive going or negative going) cycle of the AC wave.

Taking one diode away doesn’t pass 3/4 of the wave, but rather takes out an entire pair of diodes or half the full-wave rectifier.

--- End quote ---
I put a jumper in its place so I think that it will not act the same as if I had taken it away. It's gonna do something.
Actually, when I get my new supply, I will breadboard it to see what happens.
PA0PBZ:
Ehm… if what I see is correct then I found your problem… Are the 4 pads with the red line all connected to each other?

Hextejas:

--- Quote from: PA0PBZ on December 16, 2018, 03:48:43 pm ---Ehm… if what I see is correct then I found your problem… Are the 4 pads with the red line all connected to each other?



--- End quote ---

No, they are not. But thanks for looking.
sokoloff:
Do you have any 9VAC to 24VAC wall transformer available?

If so, I'd first remove R3 and R4.
Then, put the output of that wall wart across U1 and U2 and measure the output and stability of that upper stage.
Then, remove it from there and connect across U3 and U4 and measure the output and stability of the lower stage.

Then, remove and jumper (short) U2 and U3 together and put the wall wart across U1 and U4.

Perhaps first measure the resistance across U5 and U6 and U7 and U8 on an unstuffed board and on a board with everything except the diodes and R3/R4 stuffed.

If all of that is OK, then see if the board can be powered from the intended transformer with R3 and R4 removed.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod