current limiting circuits ...?

[bulerias]

hi,
where can i find current limit circuits (for 50ma current)example to build from scratch,
and is there any ICs that do that as a singke solution?
thanks for any help...
bull

 

[year]

Please check Classic Current Limit Circuit TR based.

Transistor is very cost effective and robust.

 

[M!k]

You can also use a programmable voltage regulator (e.g. LM117/317) + additional resistor.
Take a look at LM117/317's datasheet.

Mik

 

[sc/mp]

Try : JFET + resistor

 

[sc/mp]

This link shows you the current limiting with a N chanel JFET.

---> h**p://www.huebsch.at/train/Elektronik/Beleuchtung.htm

You must use a JFET with IDSS > 50mA
Check also power dissipation in the JFET

Here is my curves from Proteus (not the same JFET !) :
The resistor biases negativly the Gate.
You must adjust resistor to catch your current limiting value.

 

[jzaghal]

50ma Current Limit !!!

Hi,

A very nice current limit would be to use the TL431A chip
whis is widely available.

Look for it's datasheet on the www.

Bye.

 

[sc/mp]

Yes, TL431 is a good idea :

Bye

 

[penrico]

I think, using a transistor is a good sollution

In the image, the current is fixed by the formula: (Vdiode-0,7)/R