SSLV1.1 builds & fairy tales

diyAudio Chief Moderator
Joined 2002
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I have finally put together a pair of SSLV1.1 kit, now targeting 10-13V at 0.9 - 1.1 A

I am using:
Q101 = Q106 = IRF9530
Three green LED
R set = 0.5R
"See text" = c. 2 x red LED, R303 = 1.8K, 5K trimmer and other parts jumper.

I connected 18V AC to the board, and a 12R dummy resistor.
Upon switch on, all LED light up, no smell, no smoke, no pop....and no heat as well (except the dummy resistor)
The voltage across the dummy = 17.9V
But turning the trimmer do not have any effects.

How to locate and correct the mistake I have made, please??

Try with a higher value load to see if anything changes. Short the 1.8K with a crock, turn the trimmer. Does it work now? Then check that the MOSFETS measure a few Volt Vgs and the BJTs about 0.6V Vbe. Make sure you did not misplace a JFET for a BJT, that the MOSFETS are the correct polarity type etc.
 
Hi
salas I have the problems the voltage I need+ -42V the positve side is fine
but the - side if I turn on it alone it work correct V when I switch on power amp pre or other its make volt drop to 12.3V and IRF 610 get hot and loud distort sound . it happen when switch on or plugging other equipment.
and when turn off this regulate on -V(normally it take 20 second green led still light on) sometime its just 1-2 second and have distort sound at the output. maybe its the same problems but why happen only - V I try to change IRF610 2sk117gr IRF530 it look better but still happen somtime.
 
Ray hi,

I would suspect Q106, Q105 & Q104. Measure for Vgs, Vbe.

Hi Salas, I have started to look at the problem with my positive regulator. For completeness here is the info I posted previously;

Target voltage is 15V. Load current is 350mA and I'm adding 135mA shunt, so total current = 485mA.

R1 on both is 6R8. Transformer is 25VA with 15V secondary. I'm using a 47R 10W resistor as the dummy load (15/47 = 320mA).

The negative supply is fine and currently steady at 15V. I'm measuring a voltage drop of 2.6V across R1 so around 380mA current. That all looks fine to me.

On the positive supply I'm getting a Vout of around 17.8V that I cannot adjust. All LEDs are lit. I'm measuring a voltage drop of 2.6V across R1 so around 380mA current, just as for the negative supply.


So, here are some measurements as you suggested;

Q104 Vbe = 0.51V (Vbe is between pins 2 and 3 of the device)

Q106 Vgs = 0.01V (Vgs is between pins 1 and 3 of the device)

I didn't measure Vgs for Q105 as the schematic shows them with a common connection to R106. Q105 Vds = 0.01V

I suspect that the 0.01V readings are actually 0V and reflect errors in my multimeter; maybe Santa will bring me a new one for Christmas!

Dead Q105?

Ray
 
Try with a higher value load to see if anything changes. Short the 1.8K with a crock, turn the trimmer. Does it work now? Then check that the MOSFETS measure a few Volt Vgs and the BJTs about 0.6V Vbe. Make sure you did not misplace a JFET for a BJT, that the MOSFETS are the correct polarity type etc.

Salas.....thankyou for your reply....
"short the 1.8K with a crock".....should I short it or cut it??:confused:....must be my English...:)
Q302, Q303, and Q305 = K117
Q304 = BC 550
Will try a higher value dummy, 24R??....and report back.

Thankyou kindly and cheers,

King
 
Try with a higher value load to see if anything changes. Short the 1.8K with a crock, turn the trimmer. Does it work now? Then check that the MOSFETS measure a few Volt Vgs and the BJTs about 0.6V Vbe. Make sure you did not misplace a JFET for a BJT, that the MOSFETS are the correct polarity type etc.

Salas....you are the man....I jumper the 1.8K....and the whole thing turns into life and heat.....(with 12R dummy same)
Trying to keep it cool a little bit, I input 11-12 V AC into the board instead of 18V AC.
It turns cool with warmth......but I can only get max out-put 11.8 V across the 12R dummy (changing the R set to 0.4R does not change the max output voltage).
I would think 12-13 V AC input will be the best for my application here.

Is there a way to lower a 18V AC to be 13V AC before connecting to the board please??

Any other suggestions most welcome.

Cheers,

King
 
Find a lower value instead of 1.8K that puts you into preferable Vo range. Parallel 1K to it for starters. Keep 5Vdc vin-vout min in all cases.

Do you mean parallel a 1K with the 1.8K ?? Shall try that.

Is the voltage across C105 = Vdc in ??
Again I will look into that.

I am trying to use htis to filament bias a 26 tube.....just an experiment and hoping for a present surprise.

Cheers,

King
 
diyAudio Chief Moderator
Joined 2002
Paid Member
5VDC in-out always applies to keep the CCS well performing. Not that it does not work with less, but compromised.
You need a real sink, not that big L bracket only in your picture. Or bolt the bracket to a metal box with thermal paste in between.
Reg with Mosfet output goes down to about 5V, with BJT output to about 2.5V. Its all in the manual's specs.