Description:
A truly
timeless circuit. LM317 is a versatile and highly efficient 1.2-37V
voltage regulator that can provide up to 1.5A of current with a large
heat sink. It's ideal for just about any application. This was my
first workbench power supply and I still use it.
Since LM317 is
protected against short-circuit, no fuse is necessary. Thanks to
automatic thermal shutdown, it will turn off if heating excessively.
All in all, a very powerful (and affordable!) package, indeed.
Although LM317
is capable of delivering up to 37V, the circuit pictured here is
limited to 25V for the sake of safety and simplicity. Any higher
output voltage would require additional components and a larger heat
sink.
Make sure that
the input voltage is at least a couple of Volts higher than the
desired output. It's ok to use a trimmer if you're building a
fixed-voltage supply.
Problems:
Follow all the
safety precautions when working with mains voltage. Insulate all
connections on the transformer.
Possible
uses:
Variable
workbench power supply, fixed-voltage supply... Just about any
possible application when no more than 1.5A is necessary.
