New Snubber Board v.3 - Up in smoke

[needlz]

Hey All,

I have a single transformer wired to a single snubber board to run the amp boards in stereo. I checked the voltage on the secondaries before wiring them to the snubber and all was good... when I sent the juice to the populated snubber board, the bleeder resistors (r3, r4) went up in a blaze of glory. Do I need to do anything else before sending juice to it? I wanted to check the pg+/v+ & pg-/v- outputs before wiring it to the amp boards.

thanks.

 

[homer09]

are your caps on the right way? how about your diodes?

check everything and compare your populated board to pics of Brian's in his gallery. probably a little mistake somewhere.

 

[needlz]

Yeah... the board is fine. Only the bleeder resistors were effected.

 

[needlz]

Do pg+/v+ & pg-/v- need to be connected to anything before I send juice to the AC1/AC2 side? I just went through the board and everything is fine. No idea why the bleeders are blowing out.

 

[Jean]

Maybe your bleeder resistors are wrong values, so there is too much current going through them ?

 

[loong]

Maybe your bleeder resistors are wrong values, so there is too much current going through them ?

My 2.2K 2W with 12,000UF cap works fine. My friend's system use 10K 5W with 40,000UF cap and it works fine too. Just wonder how to compute the valid rang of valid? Any advice? Thanks.

 

[needlz]

Hot d*mn... that's it. I was using a 2.2ohm instead of a 2.2K ohm for the bleeders. My eyes are getting bad. Would this cause the fireshow?

 

[homer09]

uhmmmmm YES

you had 1000x more current flowing through the resistors and they have the same 2W rating....

 

[carlosfm]

Hot d*mn... that's it. I was using a 2.2ohm instead of a 2.2K ohm for the bleeders. My eyes are getting bad. Would this cause the fireshow?

Of course, that's practically a short.

 

[dsavitsk]

Hot d*mn... that's it. I was using a 2.2ohm instead of a 2.2K ohm for the bleeders.

I can't tell you how many times I have ordered the wrong resistors -- either adding or omitting a K. Oddly, this never happens at DigiKey and nearly always happens at Mouser. Fortunately I have never gone so far as to actually solder them down. I do wish, however, that people would use the "R" notation, i.e., 2.2Rohm as this would help me tremendously. It is hard to see that K in there and the presence of the R would force me to look for something. Maybe an R looks enough like a K that I'd screw it up anyway.

-d