LM317 for variable current control?

[Lostgallifreyan]

Circuit idea for linear current control from zero amps to fixed maximum.


|ŻŻŻŻŻŻŻŻŻŻŻ| R1
Ą-------| LM317 T |----/\/\/\----x----x------Ą
Ś |___________| Ś Ś Ś
Ś Ś Ś Ś Ś
x !------------Ą Ś Ś x
Ś VR1 Ś _Ś_C2
Ą----/\/\/\----x
x R2 Ś D1 D2 Ś ŻŚŻ x
Ś Ą---/\/\/\---x---|<|--|<|---! Ś Ś
Ś Ś Ś Ś
!------x--------------------------------x------!


VR1 10K Lin
R1 1R 2W
R2 10K
D1,D2 1N4001
C2 1000ľF Electrolytic


I don't expect extreme accuracy from this, but could it work ok? Is it a
disaster waiting to happen? Comments welcome.

Can I expect to get close to maximum output if the R1 side of VR1 cannot
fall below 100 ohms, given a high enough R2 side for VR1? And if so, how
close, and how high might the total resistance for VR1 be allowed to go?