There is no clean and easy way to add a full current limitation to the 317, especially if it needs to be adjustable. A half-cooked option is to insert a sensing shunt+transistor in the GND return, but it does not allow the output to completely collapse, and making it variable is another nightmare.
If you need such a feature, opt for a different chip: IIRC, ST has a similar IC (a Lxyz), but in a pentawatt case including a current limiter
If you need such a feature, opt for a different chip: IIRC, ST has a similar IC (a Lxyz), but in a pentawatt case including a current limiter
For adjustable current it is common to use a second 3 terminal regulator.
basically a variable pot around the sensing resistor.
and just a current source for a ref voltage
Should check out TI website and data sheet for
the LM317
There is a good 20 or so additional application notes
in the technical documentation section
likely find something in Application Note -128
most TI application notes are interested
in selling their products. So typically they use a LM113 for a 1.2 volt voltage reference
you could likely just use a normal diode string for a 1.4 volt reference.
then just a 10 to 15ma current source.
basically a variable pot around the sensing resistor.
and just a current source for a ref voltage
Should check out TI website and data sheet for
the LM317
There is a good 20 or so additional application notes
in the technical documentation section
likely find something in Application Note -128
most TI application notes are interested
in selling their products. So typically they use a LM113 for a 1.2 volt voltage reference
you could likely just use a normal diode string for a 1.4 volt reference.
then just a 10 to 15ma current source.
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Too complicated for me....
And if I use a very old L200 instead of LM317? Schematic is very similar...
And if I use a very old L200 instead of LM317? Schematic is very similar...