Hello
I need to find a laser driver circuit that can drive a laser diod emitting 1 mW. The laser will be driven with 70 kHz and 50% duty cycle (that is a peak of 2 mW).
The laser power should be regulated with a DA-converter, preferably adjustable from 0 to about 1 mW.
And I need some laser safety that shuts down the laser in case of malfunction. Maby some kind of watch dog timer circuit.
So what options are there (preferably IC-circuits)?
What wavelength? A 2 mW visible laser is class 2, so you might not need an interlock. As for the watchdog, you can use a retriggerable monostable, but you'd have to have something to drive it with, e.g. a spare MCU pin.
Cheers,
Phil Hobbs
Visible lasers 1 to 4.999 milliwatts are Class IIIa. Visible lasers .4 microwatt to .999 milliwatt are Class II. At least in the USA - 21 CFR
1040.10 and .11.Laser pointers legally sold in the USA are in one of these two classes - usually Class IIIa. (Britain limits those to Class II.) These do not legally require interlocks, keys, safety goggles, etc.
The regulations beyond product labeling and certification kick in when you hit Class IIIb - 5 to 499.9 milliwatts. Although workplaces and schools can have their own safety rules for Class IIIa and Class II lasers, such as a requirement to wear goggles, etc.
- Don Klipstein ( snipped-for-privacy@misty.com)
Must have changed. I have a drawer full of 2 mW "Class 2" HeNe lasers.
Cheers,
Phil Hobbs
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