Need help! I don't know whats wrong with my LM317!

[luccax]

Well, i built this LM317 today but when i test it with my own test load i fail, the current is allways 0. I'm sure there is current trought arriving to the LM317 (tested with multimeter).

What may be wrong? Can you please check if i connected it right?

Is my LM317 broken? How can i check if it's broken?

Thanks...

Photos:

 

[anselm]

Hmm, yeah.........
Unless you draw us a shematic of how all that is wired, I don't think anybody
will be able to help you from just these pictures...

 

[Leodahsan]

are you not shortcircuiting the resistors with the heatsink?

 

[Eudaimonium]

If you tested the current flow with multimeter, that is, if the current is flowing, that means it's flowing through an entire circuit and it's working.

Your wiring, although a bit messy, is fine. Problem is your current measurement techique.

Take a picture , or draw a schematic, of your multimeter measuring the current. Both in and out.

From that, I'll tell you EXACTLY what was wrong with your readout.

EDIT - Addendum. You have a fan on top of the box, but it's exactly useless. There are no holes on the other side of the box for the forced air to come out of. That means the air won't even go into the box since it can't push out the air that's in the box already - out of it.

 

[luccax]

Allright, i did it on autocad so it may look complicated to understand...

 

[Eudaimonium]

Allright, i did it on autocad so it may look complicated to understand...

That would be the schematic.

You need to add a Multimeter in it, to show me how are you measuring the current.

 

[luccax]

Well, that the problem, my multimeter shows 0 on the testload and i can only see voltage before my driver, the schematic is over there.

The heatsink is probably shortcutting, today i'll buy something insulating for that

 

[luccax]

I'm not home right now so i can't post the pics, anyways, im measuring in the resistor terminals of the testload.

Is that schematic right?

Thanks for the interest in helping me

 

[Eudaimonium]

Well, that the problem, my multimeter shows 0 on the testload and i can only see voltage before my driver, the schematic is over there.

The heatsink is probably shortcutting, today i'll buy something insulating for that

Voltage before the driver means you are measuring the voltage of the battery.

You are not measuring CURRENT as you stated before. Current is measured by playing the DMM in current-measuring mode in series with component you want to measure.

Voltage is measured across the component, in parralel.

What does your test load consist of, and what are you using to power up your driver?

Also, please make entire test load measuring schematic.

 

[Leodahsan]

the target amp is 620mA? your design is correct, maybe the resistors or the LM317 got fried...

 

[luccax]

Well, i understand series and paralel!!

Later when i get home i'll take more pictures!

thanks, again.

Leo:
Sim, eu quero uns 620mA num diodo c@s!0 A140 para ter mais tempo de vida e ligar num ciclo de operação maior!

 

[luccax]

One more thing, i'll also put a capacitor in paralel with the diode, wich one should i use?
Like, 10 uF is enough? Wich voltage?

 

[Eudaimonium]

Any capacitor is good.

Make sure you read the edited addendum I've made in one of me earler posts up there, the one about the fan on your box.

 

[luccax]

I have made holes on the other side of the box!! That photos were before i finished the contruction!

 

[luccax]

Can the aluminuim be shortcutting my electronical components?

Maybe the terminals have some insulation?

 

[Benm]

Thats certainly possible.. post some photos of you current setup so we can diagnose.