# LM317 Calculator or LM317 Toolkit Software

Program to calculate the resistance at a LM317 / LM117.

LM317 toolkit software is completely free, fully functional and easy to use. It runs under Microsoft Windows NT, 2000, XP and Vista.

###### 21 comments on “LM317 Calculator”
1. Rajen Shah says:

This is really a useful tool

2. vijay lashkari says:

sir i want this calculater software

3. Jacques STEVELINCK says:

Many thanks for the LM 317 Calculator

4. Excellent tool…works well. I needed to find R2 resistor values for a 3.3V regulator using the LM317L. This calculator solved it well…circuit was produced and tested… output voltage was 3.314V.

5. Ricfed says:

very good

6. manuala says:

stutiy

to trasform these usefull program in the LM350 calcolator too.

Thankyou

Marco (italy)

8. Marcelo says:

Saludos

9. Hi, i am working on a project and i found this simple program very useful.

10. N A says:

AAAAA

11. Jan H says:

Many thanks for the software

12. vu the anh says:

Rajen Shah :
This is really a useful tool

idea ,I like it thank so much for your help

13. ivam says:

ivam :
ok

14. suranga says:

ස්තුතියි.
ජය වේවා……

15. Venelin B says:

Many thanks for sharing!

16. Jose Fernández says:

Muy útil y funcionando muy bien. Gracias por la aportación. By Rey

17. How can i get the software?

18. jun aplaon says:

Thank you” Very Help full tool.

vcer thanks

20. Fran Hoffart says:

The typical value for R1 should be approx 240 Ohms, not 470. With out any external load, a 470 Ohm resistor will only provide 1.6mA of current through the 470 resistor. Since the LM317 is a floating regulator (it has no ground pin) all the operating current must flow to the output. Look at the “Minimum Operating Current” curve in the data sheet and you will see that using 470 for R1 will only provide a load on the output of 1.6mA, which is on the very edge of the curve, and the curve is only typical, it could be higher. Of course with any additional load at the output, the regulator will be OK, but if the external load is removed, the output could go out of regulation.

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