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Hi Salas
Am using salas v1.3 with soekris DAC from past 6 months, suddenly I observed smoke from cabinet and turned off the.
I rechecked all the connections and currently disconnected from dac and verifying the voltages.
I mounted on the base plate and checked the connectivity from mosfet plate to chassis (there is no short)
Earlier am able to adjust the voltage and have set it to 12v, now am unable to adjust the voltage.
On turning the trim pot only Led’s brightness is increasing and decreasing.
On turning off the power supply, on +ve channel(defective) led’s are turning of immediately
-ve supply is working fine.
Please help me out on fixing the issue.
Regards
Am using salas v1.3 with soekris DAC from past 6 months, suddenly I observed smoke from cabinet and turned off the.
I rechecked all the connections and currently disconnected from dac and verifying the voltages.
I mounted on the base plate and checked the connectivity from mosfet plate to chassis (there is no short)
Earlier am able to adjust the voltage and have set it to 12v, now am unable to adjust the voltage.
On turning the trim pot only Led’s brightness is increasing and decreasing.
On turning off the power supply, on +ve channel(defective) led’s are turning of immediately
-ve supply is working fine.
Please help me out on fixing the issue.
Regards
Not normal unless explainable by low Ic current and high radiated temperature on Q1. R1 doesn't need be so powerful. What is on R1 is Q1's Vbe. BJTs have a negative temperature coefficient. Try another Q1. Unless it's about small Vin-Vout margin. Should be no less than 5V between C1 and output. In that case change the transformer. Also IRF9610 is not reliable for well over 1A operation. Try IRF9630 if that's the problem.
Transformer is 12VAC 50VA and target voltage is 10+ VDC. I suspect that it doesn't have such a good regulation because for 1A load it gives about 14 VDC at C1. I'll try reducing output voltage to get close to 5V headroom. R1 is 0R33.
Manual suggests IRF9610 for > 1A, I guess for over 1.5A IRF9630 is better (I remember using IRF9530 for BIBs). With BIBs the two 10W resistors for R1 are getting very hot so I opted for a big one which can be mounted on a heasink.
As I have written it's special use for a friend of mine (you know him). It's quite inefficient way using UBIB but having tested L-adapter and BIB, he likes the later so UBIB is in order now.
Manual suggests IRF9610 for > 1A, I guess for over 1.5A IRF9630 is better (I remember using IRF9530 for BIBs). With BIBs the two 10W resistors for R1 are getting very hot so I opted for a big one which can be mounted on a heasink.
As I have written it's special use for a friend of mine (you know him). It's quite inefficient way using UBIB but having tested L-adapter and BIB, he likes the later so UBIB is in order now.
Reducing target voltage to 9VDC (so 5V headroom is achieved) it gave 0,514V through R1, much better. Output ripple is minimum, some mv. I'll try 9630 tomorrow (fingers crossed the only good shop here has it).
I wouldn't push BIBs / UBIBs that much, 300ma / 200ma for DCG3 is as far as I go (even these are quite troublesome to keep cool inside a chassis). I must add that there is experimental purpose also involved here.
I wouldn't push BIBs / UBIBs that much, 300ma / 200ma for DCG3 is as far as I go (even these are quite troublesome to keep cool inside a chassis). I must add that there is experimental purpose also involved here.