Marcus2012 > you should look fake lm317 and lm317 pot burn on google. This is what i thinked about the price but no, I assume a fake lm317 cost 5cents and a genuine cost 30cents.

So today i smashed a fake lm317 (pot burns) and inside there is a very very small 1*1mm chip, the genuine ones have a bigger chip inside.

A guy exactly find what i did : http://imgur.com/a/VKrvl

fake LM317 issues :
-Can Explode
-Not real max current
-Pot burns

Don't buy chineese LM317 (or other regulators) on china site (ebay, aliexpress...)

I bought some for Tayda electronics and they work great !

 

Well, maybe you can show the boys what 160v can do to some nice 317 regulators.

 

Have a look at http://pdf.datasheetarchive.com/indexerfiles/Datasheets-D7/DSAHI000135681.pdf

which is a ti datsheet for the LM117/317

Have a look at para. 4

"Besides replacing fixed regulators, the LM117 is useful in a wide variety of other applications. Since the regulator is “floating” and sees only the input-to-output differential voltage, supplies of several hundred volts can be regulated as long as the maximum input to output differential is not exceeded, i.e., avoid short-circuiting the output."

Maybe ti are a bunch of deluded fools.....

Of course this could be a fake LM317 datasheet.

 

Marcus2012 > you should look fake lm317 and lm317 pot burn on google. This is what i thinked about the price but no, I assume a fake lm317 cost 5cents and a genuine cost 30cents.

So today i smashed a fake lm317 (pot burns) and inside there is a very very small 1*1mm chip, the genuine ones have a bigger chip inside.

A guy exactly find what i did : http://imgur.com/a/VKrvl

fake LM317 issues :
-Can Explode
-Not real max current
-Pot burns

Don't buy chineese LM317 (or other regulators) on china site (ebay, aliexpress...)

I bought some for Tayda electronics and they work great !

I bought some regulators of eBay, think it was 10 for £0.99 (7805/08/12 all ST). They all seem to be fine so far but maybe I've just got lucky and I've never run a linear regulator at full rated load. I can't imagine there are a lot of them about, not like that fake SD card fiasco. I believe you, no doubt, I just haven't encountered them myself.......yet.

 

Hello every one,
Sorry it took long, actually original LM317T took long enough to start the circuit again.

Not i have build same circuit with LM338t with 2 amp 24v transformer and it worked!!

I used 1watt 5K pot and original LM338T from TI. Now the new problem is i want to adjust amps also just like volts.
How to add Potentiometer for Amp adjustment?

Please help.
Thanks

 

Hi

Have a look at p.18 of the data-sheet I referenced in #163.

You are not going to like it.

 

I used 1watt 5K pot and original LM338T from TI.

Why did you use a 1W pot?

 

Why did you use a 1W pot?

Normal pot keeps on burning, it may be because of fake LM317, but i dont want to take chances. so i used 1 watt pot

 

Normal pot keeps on burning,

That's the universe trying desperately to tell you something about your design / build,

 

That's the universe trying desperately to tell you something about your design / build,

Haa Haa haa... Thanks to every one... My LM317 was actually of poor quality... Now i build the same circuit using LM338 (original) and worked well.

I have seen many power supply videos and pics... they have 2 pots, one for volts and other one for amps control.
now in the same simple LM338 circuit, How to wire second pot that controls amps?

Please through some light on it...

I have volt+amp meter (single unit) and also separate amp meter.
Please suggest and guide me the wiring for Amps meter and its relative potentiometer.
So that i can control Amps also along with volts, i understand reducing and increasing amps affects volts shown on volt meter.

Please thats the last step, nut am not getting it. Help please.

this is the circuit am using (see attachment please)

Thanks in advance.

 

they have 2 pots, one for volts and other one for amps control.

I think you may want to find out if they set voltage / current output or they set voltage / current output limits.

 

The schematic you attached is the screenshot I attached earlier in this thread from the LM317 datasheet. As you have not altered the values for many of the components AND are still asking for current limiting after it has been answered MANY TIMES I can only assume you STILL have not read the datasheet. In addition to this we still have no idea what voltage you even want.

 

The schematic you attached is the screenshot I attached earlier in this thread from the LM317 datasheet. As you have not altered the values for many of the components AND are still asking for current limiting after it has been answered MANY TIMES I can only assume you STILL have not read the datasheet. In addition to this we still have no idea what voltage you even want.

i actually have altered, i used 2200uf cap before Ci, used 5k 1watt pot, In4007 diodes as D1 and D2, 10uf 50v as C adj , .1uf as Co, R1 = 220 ohms. System works and gives 29.xx volts nearly 30v. and i can adjust it to 1.2v. Everything is working very fine.

I want to add another potentiometer that will act as Ampere controller. Like many power supplies have. Please tell me how and where to wire that second potentiometer for current adjustment in separate.

Thanks