Hello,
I am working on troubleshooting a problematic SMPS that kicks off after a few moments of load.
Looking around the PS for loose/broken solder joints, and notice there is a missing capacitor (C5) between pins 2 (Error Amp1 - ) and 3 (feedback pwm comparator input) on the TL494.
Often I find unused solder pads on circuit boards, but not on this one. This is the only designated area on the whole board with nothing on it. I cannot say with any certainty if there was a capacitor there or not.
Looking at the datasheet, I think it should be a 0.01 Cap (uf?) and only see this cap present for a push-pull converter and I think a step-down converter.
My suspicion is this missing capacitor is screwing up the voltage/power sensor circuit and tripping the cut-off.
Does someone out there with a lot of experience with TL494's confirm there should be a cap between these two pins? If so, confirm 0.01uf is the correct value. Or possibly theorize if this cap has anything to do with the cut-off.
Let me attach a picture of the 'area'.
Anyone have a spare?
I am working on troubleshooting a problematic SMPS that kicks off after a few moments of load.
Looking around the PS for loose/broken solder joints, and notice there is a missing capacitor (C5) between pins 2 (Error Amp1 - ) and 3 (feedback pwm comparator input) on the TL494.
Often I find unused solder pads on circuit boards, but not on this one. This is the only designated area on the whole board with nothing on it. I cannot say with any certainty if there was a capacitor there or not.
Looking at the datasheet, I think it should be a 0.01 Cap (uf?) and only see this cap present for a push-pull converter and I think a step-down converter.
My suspicion is this missing capacitor is screwing up the voltage/power sensor circuit and tripping the cut-off.
Does someone out there with a lot of experience with TL494's confirm there should be a cap between these two pins? If so, confirm 0.01uf is the correct value. Or possibly theorize if this cap has anything to do with the cut-off.
Let me attach a picture of the 'area'.
Anyone have a spare?
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