Hi,
I am trying to make a power supply circuit, which has to supply 5V @ 50mA max, and 15V @ 1 mA max.
I was thinking of using a single phase rectifier with 1 diode, a reasonably sized cap of say 47µF, and behind that for the 15 V part, just a zener and a resistor, and for the 5 V part an 7805.
However, the 7805 can only take 35 V max, and also I do not have any space for large cooling or anything.
Is there a simple and cheap way of limiting the input voltage to my 7805, without having to just dissipate it through a series resistor ?
thx
I am trying to make a power supply circuit, which has to supply 5V @ 50mA max, and 15V @ 1 mA max.
I was thinking of using a single phase rectifier with 1 diode, a reasonably sized cap of say 47µF, and behind that for the 15 V part, just a zener and a resistor, and for the 5 V part an 7805.
However, the 7805 can only take 35 V max, and also I do not have any space for large cooling or anything.
Is there a simple and cheap way of limiting the input voltage to my 7805, without having to just dissipate it through a series resistor ?
thx