Sjöström Audio DIY forum

Projects => Power supplies => Topic started by: a333bt on May 15, 2012, 01:47:21 AM

Title: SSR02 and SSR01 voltage
Post by: a333bt on May 15, 2012, 01:47:21 AM
Hi,
i have problem with SSR02 voltage.
Plan to use SSR01 and SSR02 to supply Hiraga amplifier with +-12V, 500mA bias.
With SSR01 i got 12V, but with SS02 i got only -8V instead -12V.

More data:
using AD797
input voltage from capacitor tank (55000uF) is +-14.6V
Voltage at AD797 pin2 is 3.17V at pin3 is 2.4V.

I removed preregulator LM337 to get more input voltage, because of 2.5V drop, but it came same output voltage 8V.

Could you help here?

Regards,
Bostjan
Title: Re: SSR02 and SSR01 voltage
Post by: peranders on May 15, 2012, 06:29:28 AM
The problem is that the feedback voltage is higher than the reference.

Voltage at pin 6 and 7?

Do you use LM431? If yes, resistor values around that part?
Title: Re: SSR02 and SSR01 voltage
Post by: a333bt on May 15, 2012, 07:10:21 PM
Hi,

voltage at pin6 is 1.2V; at pin7 is 0V

I use LM329

regards,
Bostjan
Title: Re: SSR02 and SSR01 voltage
Post by: peranders on May 15, 2012, 10:05:48 PM
Pin 7 should be ground, correct but I ment the pin 4?

You have put tin drops on the solderside at J1 and J2?
Title: Re: SSR02 and SSR01 voltage
Post by: a333bt on May 16, 2012, 06:28:52 PM
Hi,
pin4 is 8.11V.

About jumper J1 and J2 (senses), i dont get it what i must do. Do i have to make short with tin drop?

Bostjan
Title: Re: SSR02 and SSR01 voltage
Post by: peranders on May 16, 2012, 09:05:08 PM
Yes, please read my text. Read the section about the sense function. Those input must always be connected. I have my doubts though feeding the AD797 from the output since the opamp must have at least 10 volts as supply voltage. If you put tin drops at the J1 and J2 and still won't get any function you can feed the opamp via R5 instead of R6.
Title: Re: SSR02 and SSR01 voltage
Post by: a333bt on May 17, 2012, 07:06:07 PM
Hi,
i put tin drops on JP1 and JP2.

I measure some points, if helps:

AD797
pin2: -3.11V
pin3: -2.35V
pin4: -8.07V (also -14.6V tried)
pin6: -1.18V

Q2 D45H11
pin1: -1.89V
pin2: -14.6V
pin3: -8.17V

regards,
Bostjan
Title: Re: SSR02 and SSR01 voltage
Post by: peranders on May 17, 2012, 07:24:23 PM
Is the Lm329 in the position with the thin outline? The thick outline is for LM431.
Title: Re: SSR02 and SSR01 voltage
Post by: peranders on May 17, 2012, 07:29:48 PM
The voltage at Q2 seems not OK. Do you really have lower voltage at the base than the emitter?
Title: Re: SSR02 and SSR01 voltage
Post by: a333bt on May 17, 2012, 08:30:49 PM
Base of Q2 is -8.78V; emiter -8.17V.

Title: Re: SSR02 and SSR01 voltage
Post by: peranders on May 19, 2012, 08:44:29 AM
What about post #6? There you have base an another base voltage?
Title: Re: SSR02 and SSR01 voltage
Post by: a333bt on May 19, 2012, 10:05:56 AM
Hi,

i measure again compare with SSR01:

SSR01:

* AD797:
pin2: 6.88V
pin3: 6.88V
pin7: 5.14V
pin6: 11.55V

* D44H11:
pin1: 12.55V
pin2: 13.25V
pin3: 11.94V

SSR02:

*AD797:
pin2: -2.97V
pin3: -2.04V
pin4: -1.18V
pin6: -7.95V

* D45H11:
pin1: -8.73V
pin2: -10.73V
pin3: -8.12V

Supply voltage : +-14.7V.

Measurements are with preregulator.

I tried measure without preregulator of SSR02, but same low voltage :|

Title: Re: SSR02 and SSR01 voltage
Post by: peranders on May 19, 2012, 10:43:44 AM
You have 0.9 volts across the opamp inputs which means that the reference isn't working (high impedance) and the clamping diodes inside is active. 14.7 volts is too little for the the regulator but the problem isn't there. Try so solder in a 5.6V zener in parallel with LM329 if you don't want to remove it. Is the LM329 in the position according to my photos?
Title: Re: SSR02 and SSR01 voltage
Post by: peranders on May 19, 2012, 10:44:59 AM
As long as the voltage at pin 2 is higher than pin3 you can never get it working. It must be the other way around at startup.
Title: Re: SSR02 and SSR01 voltage
Post by: a333bt on May 19, 2012, 10:52:58 AM
yes, LM329 is in correct position.
pin1 is not connected, pin3 is grounded, pin2 has -0.8V.
But on SSR01 on pin2 is 6.98V.

Title: Re: SSR02 and SSR01 voltage
Post by: peranders on May 20, 2012, 03:07:21 PM
Notice that the LM329 should be mounted according to the thin outline meaning pin 2 ground!
Title: Re: SSR02 and SSR01 voltage
Post by: a333bt on May 21, 2012, 09:21:52 PM
Oh, yes. I looked at datasheet in it was wrong direction mounted.
Now it works like reference voltage.
But, now voltages are quite low (must of higher voltage toroid) and i have 2 of negative super-regulator and they have 1 volt difference of each other with the same input voltage. :|

Title: Re: SSR02 and SSR01 voltage
Post by: peranders on May 21, 2012, 09:53:26 PM
Which reference voltage do they have? Voltages at pin 2 and 3 of the opamp?

Just wondering, why did you mount the LM329 not according to the outline?
Title: Re: SSR02 and SSR01 voltage
Post by: a333bt on May 28, 2012, 06:25:15 PM
Hi,
sorry for late reply. I went to holidays with my family for few days.

refence voltage of LM329: 6.8V?

Colour of SSR02 was red in description for 12V LM329. I have blue one. That confuses me :-P

At moment i dont have connected to amplifier, because of low voltages. I need to test with higher voltage transfromer.

regards,
Bostjan
Title: Re: SSR02 and SSR01 voltage
Post by: peranders on May 28, 2012, 07:58:20 PM
The SSR01 and SSR02 are both exactly the same when it comes to placement. The LM329 should be between 6.6 and 7.25 volts and most devices are between 6.8-7.1 V.