marcoreps

Laser emitter simulator?

Added 2018-04-12 22:33:24 +0000 UTC

Oh boy, we've reached the 500$ Patreon goal, haven't we? Does that mean I have to move out of my cozy apartment? :L

I've assembled a laser driver and found an old phase control thyristor module, that has almost exactly the same forward voltage drop as my fiber laser when using its diode and the thyristor in series.

That way I can stress test the driver and measure / correct parameters like turn-on-spikes, slew rate, modulation bandwidth, thermal dissipation etc. without taking any risk with the actual laser.

In case of miscalculation I've prepared the PCB for an additional parallel output, but right now it seems like that will stay vacant. The point of the primary DC-DC converter (between the caps) is to drop the input voltage as close as possible to the laser forward voltage with its very high efficiency >90%. Then the output MOSFET with its terrible P = V * I efficiency only has to drop a few mV at 40 A which is acceptable.

I am still a little bit nervous about going full thrust 40A. That kind of current is only available at the back of the HP or from a big battery. Might also have to replace that flimsy freely standing fuse for that :)