eem2am
Banned
linear current regulator led
hello
please can you confirm that this LED driver is erroneous?
http://i30.tinypic.com/10qfhw9.jpg
it runs off a 13V battery.
The LMV431 is getting feedback from just one of the emitters. This seems wrong and not useful.
**broken link removed**
(page 14 details the current regulator usage of LMV431)
In practice , we find that the circuit on the PCB gives an oscillation of 2V peak to peak on the collector of the FMMT619 BJT's.
We can solve this by putting on a few 10nF caps from base to emitter of a few of the FMMT619's.
But anyway, i think it is erroneous, do you?..those two BC847C's seem to be doing nothing useful ?
Though the circuit does work - i feel it is using more components than necessary?
please could you comment?
hello
please can you confirm that this LED driver is erroneous?
http://i30.tinypic.com/10qfhw9.jpg
it runs off a 13V battery.
The LMV431 is getting feedback from just one of the emitters. This seems wrong and not useful.
**broken link removed**
(page 14 details the current regulator usage of LMV431)
In practice , we find that the circuit on the PCB gives an oscillation of 2V peak to peak on the collector of the FMMT619 BJT's.
We can solve this by putting on a few 10nF caps from base to emitter of a few of the FMMT619's.
But anyway, i think it is erroneous, do you?..those two BC847C's seem to be doing nothing useful ?
Though the circuit does work - i feel it is using more components than necessary?
please could you comment?