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current limiting circuits ...?

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bulerias

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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

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Please check Classic Current Limit Circuit TR based.

Transistor is very cost effective and robust.
 

M!k

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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

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Try : JFET + resistor
 

sc/mp

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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

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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

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Yes, TL431 is a good idea :

Bye
 

penrico

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I think, using a transistor is a good sollution

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

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