LM317 Reg with current bypass

[Gregory]

I have several LM317 and I want to build a 12V DC to 1V DC veriable power supply but want a Current by pass of 3 Amps.
Can this be done using the LM 317

 

[ericgibbs]

I have several LM317 and I want to build a 12V DC to 1V DC veriable power supply but want a Current by pass of 3 Amps.
Can this be done using the LM 317

hi,
Do you have any PNP power transistors in your stock.??

The LM317 will work down to about 1.25V min.

 

[adrianvon]

Hi,

From the datasheet the minimum voltage is of 1.2V to a max of 37V. To increase the output current you need to use a pass transistor. The tutorials below may help you:

https://www.bristolwatch.com/ele/lm317.htm
**broken link removed**

 

[electronic novice]

I have use LM317 in my power supply it outputs 1.25v to 12v DC but in that case i used multivariate transformers.

 

[alec_t]

If you draw 3A at 1V your pass transistor will dissipate at least 33W (11V x 3A). It will need a large heatsink.