Hello, I am working on a Shunt regulated DC Power supply for Audio use.
I am using a PNP transistor to regulate the amount of current the circuit provides. There is a NPN that shunts off any current not needed by the source. I am use a pot to set the amount of current that the PNP transistor passes. This works well but can someone recommend some circuitry that would keep the amount of current that the PNP transistor passes consistent from device to device?
The change from one board to the next I think is due to the part to part Hfe variation of the PNP transistors.
I are requiring extremely accurate and consistent shunt current amounts from one board to the next. I need to have the gain of the PNP transistor the exact same from one board to the next. It would be extremely nice to not have to manually adjust each one with a pot to obtain the necessary shunt current!
Thank you!
Nemo
Hi, Nemo,
I'm not sure anyone here can answer your question. Unfortunately, I'm not sure where to direct you. Can you post a schematic or something of your power supply? Won't the current need to be modulated by the audio signal?
-d2
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Don Dapkus
Audio Applications Engineering Manager
Dallas, TX USA