it blew up (the rectivier)
and i dont want to repair it
the lm317 still works
i need the powersupply for my plasma speaker
i need 24 V
Well it is so cheap that if you are handy (like me), it only will set you back 3 or 4 dollars for a nice case.
With a well stocked junk drawer, you could even make it for free.
Would you like to see what it is? It is a low voltage, variable power supply.
V1 = from 1.5 to13 volts positive output
V2 = from 2 to 35 volts positive output
With Version 1 you cannot use the higher output because the fan can only hande 12 volts.
You can modify it to handle the higher voltage, but I suggest you build Version 2 instead.
Version 2 starts in step 5.
Step 1: Bill of Material
1 - LM317 (Texas Instruments has the smd in the free sample program, the same one I used.)
1 - 10K ohm variable resistor (potentiometer) (pot)
1 - diode bridge (rectifier) or 4 fast diodes . Watch the polarity! Follow the schematic exactly.
1 - electrolytic capacitor 63V, 100-300uF (it doesn't matter.) ( Watch the polarity.)
1 - small heatsink for the LM317
1 - small PC fan (12V)
1 - small piece of circuit board
2 - connectors (so you can screw your wires instead of alligator clipping them)
1 - transformer (I used one that has 3 wires and 2 outputs, 13.5V and 27V)
Note: In order to use the full power, use a transformer that can handle at least 1A because the LM317 can deliver up to 1.5A.
1 - box
1 - line cord with plug
Various lengths of wire
1 - voltage display (mine is from an old radio control (rc) transmitter)