Aixiz 5mw laser driver schematic

[Greyfox]

After a night of no sleep, I decided to post the resulting schematic from an attempt to trace out the Aixiz driver. This probably will not work for most other lasers without modification, so I'm posting it only for information and discussion .


+--------------------------------------------+----+
| PD [ ] |
| +---/\/\/--------------+ _|_
| | 0.0 \ /
+----+--/\/\/---+-----)---+---------+ ___V___ LD
+ | | 1.2k | | \ | |
3 _|_ | | | / 56k | |
V _-_ _|_ | | \ | /E |
D - ___ | | | |/ |
C | | <- _|_ +---+-----| |
| | <-_\_/_ | |\ | /C
| | <- | / | \C |/
| | | \8.2k +----+----|
| | | / | |\
| | | | _|_ | \E
| | | | ___ |
| | | | | |
+----+----------+---------+--------------+-/\/\/--+
0.0


I'm not an electronics engineer, but this looks to me like a reasonable self-adjusting common anode driver. Anyone have any insight on turning it into a viable device for higher power diodes (assuming we find common-anode)?

 

[Benm]

Looks about right to me, i've glanced at the circuit board but didnt take the trouble to break it down to a schematic.

As far as using it for anything else, i doubt the circuit is that useful... i bet component values on these were partly determined by trail and error in the first place.

Current depends on the hfe of both transistors, as well as the exact photodiode characteristics. That's not really a problem for aixiz, since they'll have components from the same batches in every module, but it would be hard to reproduce reliably.

 

[Greenie]

Thanks. My driver came with tons of glue on it and i am too lazy to pick it off.

 

[chimo]

Looks like my DX module but the 8.2k resistor is a 3K in mine. You can squeeze a bit more from these but they are not suitable for the GB LDs.