hi all,
since i build the dac power supply without the dac chip on board.
tested result +-5 volts was ok..-15volts was ok..on the spot..
but when i plug in the dac chip..
the tda chips eats 5volts from my -15volts power supply!!.why?
+-5volts was ok...is it normal>? or i need to crank up the supply?
>pls help.
>have attach the circuit.
>
>thanks.
>rgds
>tone
since i build the dac power supply without the dac chip on board.
tested result +-5 volts was ok..-15volts was ok..on the spot..
but when i plug in the dac chip..
the tda chips eats 5volts from my -15volts power supply!!.why?
+-5volts was ok...is it normal>? or i need to crank up the supply?
>pls help.
>have attach the circuit.
>
>thanks.
>rgds
>tone
Attachments
Powersuppy Problem
Hi tone,
As I see it you are using exactly the component values used by Thorsten Loesch in his Adagio DAC. Thorstens schematic is hard to read due to low resolution but I guess you are right with the values. The output of the regulator is (1+ 5.1/1)x 2.5= 15.25 V.
The ony clue I have is that your TDA1541 has a shortcircuit for the negative supply. Did you try an other chip?. Does it get more than handwarm? What is the voltage before entering the TL431?
Hi tone,
As I see it you are using exactly the component values used by Thorsten Loesch in his Adagio DAC. Thorstens schematic is hard to read due to low resolution but I guess you are right with the values. The output of the regulator is (1+ 5.1/1)x 2.5= 15.25 V.
The ony clue I have is that your TDA1541 has a shortcircuit for the negative supply. Did you try an other chip?. Does it get more than handwarm? What is the voltage before entering the TL431?
Please check TL431. I don't sure it's still alive.
You feed -24V and need -15, so 9V drop on the 68R. You tested the PS by unpluged 1541, so at that time ~130mA drain through TL431 which is 30% higher than max rating. TL431 may went to hell already.
I feed just -18V and R drop at 39 ohm. TL431 will drain only 76mA even 1541 out of socket, Safe.
Hope this help.
You feed -24V and need -15, so 9V drop on the 68R. You tested the PS by unpluged 1541, so at that time ~130mA drain through TL431 which is 30% higher than max rating. TL431 may went to hell already.
I feed just -18V and R drop at 39 ohm. TL431 will drain only 76mA even 1541 out of socket, Safe.
Hope this help.
Well, just remind. How did you make -24V? Some series regulator such LM7924 or LM337T, has been used. It may be oscillate if you didn't put 1uF at the output of those regulators.
This was happen to me once. I connected LM337T output directly to TL431 set without C inbetween. It was oscillate. The Vout of TL431 will drop anytime I connected load, but seem work normally without load.
Hope this help too
This was happen to me once. I connected LM337T output directly to TL431 set without C inbetween. It was oscillate. The Vout of TL431 will drop anytime I connected load, but seem work normally without load.
Hope this help too
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