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Scottapotamas / stm32-camera

Custom CMOS camera board with STM32.
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Add RC snubber for IR-Cut solenoid #5

Open Scottapotamas opened 7 years ago

Scottapotamas commented 7 years ago

As suggested, a RC snubber circuit (or at least footprints to support one) should help reduce the b-emf of the solenoids during a switch event.

This thread seems to cover the theory behind selecting the R and C sizes.

Find a LCR meter to evaluate the switching element?

Potentially just trial & error the relative strength with a scope.

Scottapotamas commented 7 years ago

Hardware side is complete but specific values unknown (find experimentally) as I don't have an LCR to find the inductance of the solenoid (its about 52R though).

Scottapotamas commented 7 years ago

Software side switches the pins as a group correctly.

ds2_20178170283

Pins are left as analog state while not actively trying to switch the filter in an effort to reduce power. Both lines are pulled low with 1ms before the switch of one half.