this is the schematic ive built. Its designed to give an adjustable output of 35-50v, the question is which part do i have to change to make it work below 35v. I have this connected to a 24v transformer and all it gives out is 35v(no matter the pot position). I know this is very simple for some.
Hello there,
My question would be, what range output do you really want here?
For example, 12 to 30 volts, 12 to 24 volts, 6 to 20 volts, 3 to 20 volts, etc.
The low end and high end are needed to be able to design this circuit so that you get the range you are looking for, otherwise it's a guessing game what components you need and you'll end up trying a lot of values to get what you want.
So if you state the range that would help everyone here help you to find the right components and values.
Note that the way the circuit stands at present there will be some minimum output possible, such as 2v or around there. Getting 0v would require some more mods.
Also, you should state what current levels you intend to try to get with this circuit too, such as 100ma, 200ma, 500ma, 1 amp, etc. With some combinations of current levels and output voltages you would need an impractically large heat sink.
To properly design a power supply circuit the designer needs to know as a minimum what the output voltage range will be and what the output current range would be.