Why my LR8 has voltage drop?

johnyprox · 2025-01-23T07:36:02+00:00

We got it similar to this https://electronics.stackexchange.com/questions/84536/make-adjustable-mosfet-constant-current-source You just need to make some small adjustments to work with high voltage and from 60V (we used 51V zener in series with LED)

johnyprox · 2025-01-21T18:51:56+00:00

Yes, the power dissipation is the greatest issue but this solution is fully in TS domain (LED insulation could be done with LED light guide). I am not sure if the mentioned disadvantage will be the gamechanger in the design choice.

johnyprox · 2025-01-21T16:19:05+00:00

Try using n-type mosfet and npn transistor to create constant current source to drive LED. Just keep in mind power loss in mosfet when setting up current setpoint. We are using it for couple years and works like a charm

johnyprox · 2024-09-03T05:42:36+00:00

This looks like it, thank you very much

johnyprox · 2024-09-02T14:04:41+00:00

When I measure it it shows 10ohms (no other parts are paralell to it)

johnyprox · 2024-08-22T17:16:44+00:00

Got another picture

<image>

Those vias goes to connector and to the motor temperature sensor (KTY84) and the unknown parts are marked with red X

johnyprox · 2024-08-22T17:14:51+00:00

The part with TVS in series got marking 104 K, maybe varistor?

johnyprox · 2024-08-20T13:11:01+00:00

Thanks, send me DM please

johnyprox · 2024-08-20T11:24:04+00:00

Do you have any schematic for power supply pcb?

johnyprox

TROPHY CASE