New laser driver attempt (Patreon)

My last laser driver consisted of a high efficiency switching DC-DC converter 'to get close' and classic precise linear regulation to get the current precisely right. That works well and is safe, but not very energy efficient.

This bloody battlefield is the result of me trying to make the DC-DC converter behave like a stable constant current source to drive the laser much more efficiently. Happy to announce that the battle was won and the idea works!

It only needs a shunt resistor and a dual op amp: 1 op amp acts as a high side shunt amplifier, the other one compares the amplified shunt voltage with an analog input voltage and drives the DC-DC converters 'trim' pin accordingly.

In some cases the whole thing starts drawing tens of watts while putting out 0 ampere into the load, so some evaluation and fine tuning is still necessary ...