The oscillations occur with or without the load. I am using just a resistor to simulate the load. My actual circuit that will be the load is currently being built.
The variable seems to be the amount of current through the shunt transistor.
I do not think that buffering the load will help but I will alter the value of R7 and see how that works.
It may be that I need to use all positive regulators to run the amount of current that I want to. That will be a lot more work to do because my heatsink will need to be drilled and tapped for the positive circuit board.
Thanks for your help.
Bill
The variable seems to be the amount of current through the shunt transistor.
I do not think that buffering the load will help but I will alter the value of R7 and see how that works.
It may be that I need to use all positive regulators to run the amount of current that I want to. That will be a lot more work to do because my heatsink will need to be drilled and tapped for the positive circuit board.
Thanks for your help.
Bill
Sorry for any confusion. At 200 mA via the shunt transistor it oscillates. I have been checking out my positive regulator with the oscilloscope and it is rock stable at any load.
At this point, I plan to build more positive regulators and use them for the negative power supply. Do you think that there is a problem with that? My transformers and diodes are all separate for the positive and negative side.
Bill
At this point, I plan to build more positive regulators and use them for the negative power supply. Do you think that there is a problem with that? My transformers and diodes are all separate for the positive and negative side.
Bill
Hi Salas,
I tried varying the gate stoppers but still have oscillations and varying voltage. Is there any problem using 2 positive regulators provided I used separate transformers, diodes, and caps with the only connection being at the load?
I have changed most of the components on the negative regulator but still have the same problem and just cannot seem to get it to work at high shunt current draws.
Thank you for all your advice.
Bill
I tried varying the gate stoppers but still have oscillations and varying voltage. Is there any problem using 2 positive regulators provided I used separate transformers, diodes, and caps with the only connection being at the load?
I have changed most of the components on the negative regulator but still have the same problem and just cannot seem to get it to work at high shunt current draws.
Thank you for all your advice.
Bill
No there is no problem using 2 positives, see the pic, but there should be no such persistent problem in a negative too. Has been used a lot in +/- configurations by now. Don't know how much they pushed spare current though. So it makes me wonder. What make are the IRF610s?
Attachments
I have 3 other salas shunt supplies built and all are working fine in a +/- configuration.
They are all dumping around 100mA through the shunt.
All my mosfets are International Rectifier brand.
The diagram shown is how I plan to configure the supply except I have separate transformers for each regulator.
Thanks.
Bill
They are all dumping around 100mA through the shunt.
All my mosfets are International Rectifier brand.
The diagram shown is how I plan to configure the supply except I have separate transformers for each regulator.
Thanks.
Bill
thank you for Input
how would you compare Sonicaps to Obbligato Gold In respect to BIB
I am Interested also what Merlin does think about Sonicap v Auricap v Obbligato Gold
Is there anyway this can this be done using one transformer with a single secondary feeding both +ve boards or does each board require it's own secondary winding i.e. dual windings on the transformer?
thanks
thanks
No.
How I choose a film capacitor:
Dielectric film
1st teflon
2nd MKP
Conductor type
1st foil
2nd metallized
Conductor material
1st copper
2nd aluminium
3rd tin
Waiting it helps.
Excluding teflon dielectric, obbligato GOLD is my preference.... Way better than Sonicap.
Auricap is very good but always leaves it´s rather special signature.... Obbligato is more transparent.
Obbligato uses foil
Auricap & Sonicap are metallized
As said before always better foil over metallized.
