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ssr01 wrong output

Started by tamu, January 20, 2012, 08:41:42 PM

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tamu

Hi all, I finished building a ssr01 to power my gamma2 dac and its the 5v version. made sure I used all the parts specified in the bom.

I when I first turn the power on the DZ1 led briefly flashes and I get only 3.4v out which fluctuates a bit around 3.3 and 3.4v.

opamp pin 2 has .74 and pin 3 has .79
pin 7 is at 1.02v
my first suspect is q3 but I will check all the transistors just to be sure..

Any other ideas would be more than welcomed. :-)

peranders

#1
How much is your input voltage? For 5 V out you must have at least 10 V in if you have the LM317 installed. Are the SENSE inputs connected? Which opamp du you use?
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

tamu

Ive got a 9v 15va trafo..

sense inputs are not used (j1 and j2 are soldered)

opamp is ad825

peranders

Have you used my BOM for 5 V?
If you measure your input voltage, how much is it?
R5 in place, not R6?
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

tamu

Yep used your bom.
Trafo is 11v unloaded
R5 is in place. No r6 resistor

peranders

The opamp is placed correctly?

If you remove the R5, does the collector voltage of Q1 increase?

DZ1 is a LED and placed correctly?
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

tamu


Quote from: peranders on January 21, 2012, 02:12:03 PM
The opamp is placed correctly?

If you remove the R5, does the collector voltage of Q1 increase?

DZ1 is a LED and placed correctly?

yes

I dont know I will check that later

and yes.

tamu

sorry for the late reply..

So I removed the r5 and on q1 collector pin I have 14.4 pin 2 has 1.4 pin 3 had 9.2v

peranders

It seems that the AD825 is broken. Is R5 really 47 ohms, not 470 ohms? Was the opamp placed correctly?
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

tamu

#9
it could be.. Ill check what opamps I have and see if any is suitable.

I checked the resistor again and Im sure its 47ohms.

tamu

ordered a couple of ad825 opamps. will replace the one on the board and see what happens.

thanks for the help so far peranders. much appreciated.

tamu

swopped the opamps and still no change..

peranders

Have you used my BOM to 100% or are some parts changed?
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff

tamu

the only thing different is bc556 transistors.
I couldnt find the "c" version so I got the "b" ones.

peranders

The B, C thing should be a problem. Could you send me a couple of close up pictures?
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff