SSLV1.1 builds & fairy tales

[Salas]

Dead shorted Mosfet. Replace it, exchange for 6k8 R103 so to go up to 24V easier.

 

[Salas]

After changing it and you check that the tabs on both MOSFETS show no continuity to chassis once again, remeasure drop across the 10 Ohm R101 so we will know the new current, also feel the heat transfered to chassis so we decide if to short the fourth LED or not. Basically for a 53mA bias we will need 3 times that for full swing plus some spare that we will evaluate how much can we allow to our benefit based on idle thermal behavior.

 

[KevinHeem]

I have replacement for mosfet. Don't have 6.8K resistor, will have to get one.

 

[KevinHeem]

Ha! I found some 6.8K resistors.

Salas thanks so much for your help!

Need to put kids to bed. Will work on reg. tomorrow

 

[Salas]

Check with now R103, we got to solve the over-current situation first, after all maybe there is a new measurements situation when the main fault is corrected

 

[Salas]

Ah alright we cross-posted. Let me know tomorrow.

 

[Salas]

P.S. What is the transformer's secondary AC value?

 

[KevinHeem]

Rated for 22V. 23.50V as tested unloaded.

 

[Salas]

Seems well enough chosen

 

[KevinHeem]

Replace Q101 and Q106

Can get 24V

Voltage drop at R101 = .39

temperature at mosfets = 38C

temperature at R101 =50C

Ground to source =30.14

Source to gate = 9.1

 

[AndrewT]

Check the CCS current and the CCS voltage drop, when you have no load and when you added the load.
Repeat these two tests when mains voltage is down to the minimum from your supplier.

I think your 22Vac transformer is too low for a 24Vdc shunt style regulator.

 

[Salas]

Replace Q101 and Q106

Can get 24V

Voltage drop at R101 = .39

temperature at mosfets = 38C

temperature at R101 =50C

Ground to source =30.14

Source to gate = 9.1

Works

9610's VGS maybe less than 9.1. 4-5V would compute better.
390mA now i.e. logical value and ample spare for having low rail modulation THD (good thing). At 38C semis you may keep it. If you also got about 5VDC or more between Vin to Vout you are OK.
9610's Source to GND already indicates enough. You can measure Vin between R101 input pin and GND. Vout is 24V of course.

 

[KevinHeem]

Yes, success with the first one! Now three to go (dual supplies). Should I change R101 to a higher wattage, the heat on it makes me nervous.


I see the thread: TPS7A4001 vs Salas shunt Reg

I wonder how customer service is with that Reg?

Thanks again Salas!

 

[Salas]

Yes use higher wattage
You rework that chip with x-rays in case it fails

 

[KevinHeem]

Mosfets

I'm ordering more mosfets. I've only used the mini-kits from Teabag before. Is there a difference in this circuit between the older vs the newer ones (i.e. IRF530 vs IRF530PBF)? Looking at the data sheet they look identical to me, other than the PB being lead free.

 

[Tubenstein]

Salas,
This is a question asking on my friend behalf. Do you think he can use your SSLV1.1 as the negative supply of the cathode follower in a tube circuit? And how?

Thanks!

 

[Salas]

I'm ordering more mosfets. I've only used the mini-kits from Teabag before. Is there a difference in this circuit between the older vs the newer ones (i.e. IRF530 vs IRF530PBF)? Looking at the data sheet they look identical to me, other than the PB being lead free.

Exactly that. They are just ROHS parts.

 

[Salas]

Salas,
This is a question asking on my friend behalf. Do you think he can use your SSLV1.1 as the negative supply of the cathode follower in a tube circuit? And how?

Thanks!

He can use it as any other -V supply if its output range is enough for the purpose

 

[king4joy]

Has anyone tried using the sslv1.1 to power a TA 2024 or a TA 2020 T amp ??

Any suggestions please??

 

[king4joy]

Has anyone tried using the sslv1.1 to power a TA 2024 or a TA 2020 T amp ??

Any suggestions please??

Salas....what do you think please??