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

Parts List:

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)
there is a litle problem<br /> <br /> adj.-out resistance should be at least 220 ohms&nbsp;&nbsp; so if you put your pot all the way up it will short adj.-out (0 ohms)&nbsp; not realy good for the lm317<br />
ya i know<br /> but mine still works<br /> <br /> i did blow it when i powered a flyback transformer<br /> <br /> so the next version has some sort of protection
OK, I made some corrections.&nbsp; Version 2 needs its own schematic though.&nbsp; It needs to show how to place the LED, the switch, and the resistor for the LED.&nbsp; Also, you really should include a fuse on the hot side of the line cord before the transformer.&nbsp; Otherwise if something happens, you have a nice little fire starter.
that would be smart (the fuse)<br /> <br /> mine has a thermal fuse build in
For some reason I wasn't able to correct some of the embedded captions.&nbsp; Maybe you can.&nbsp; &quot;connector&quot; is misspelled every time (2 &quot;n&quot;s in the middle).&nbsp; How do you like my update?&nbsp; Where is the thermal fuse?
the thermal fuse is imbeded inside the transformer<br /> <br /> the label shows that it can take 135 degre's celcius<br /> <br /> i will coorrect connector
I always enjoy your I*, if only to try and figure out what you're saying.&nbsp; I offer you encouragement - and safety!
thank you<br /> <br /> i am corecting a lot on my grammas mistakes latly<br /> <br /> so i can be be understandeble for others.<br /> <br /> but it will never be the best
I&nbsp;also offer my help, if you want.
sure that would be nice
Robot797,<br /> <br /> What I&nbsp;was thinking was to download your I*, make some corrections, then send it back to you to post.&nbsp; I don't want any credit.&nbsp; I just think you have a good I* and it needs to be understand.&nbsp; Or, I could just send you the corrections to make on your own. My email: mathman at comcast dot net.&nbsp; Understand how to make this into an address?&nbsp; I'm doing it this way so the bots don't have such an easy chance.&nbsp; Glad to help.
i&nbsp;<font size="3"> collaborated you into the project<br /> if i am correct you can now edit it<br /> <br /> if not you will get it via e-mail</font>
I did something similar as well ... 2 days ago. When I finished my dinner (china food), I was left with one bow like yours ... so I decide to put the power supply for my Proxxon there ... and it fits exactly, like the box was made for it :) ... and it is water resist as well.<br /> <br /> Good thinking :)<br />

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