Ammeter on ext of case: test functionality, recalibrate as needed

[heaventwig]

We don't know if this device is reading properly. (The question arises partly due to the obviously miscalibrated voltmeter display on the voltage regulator.)

[Hurricos]

BTW: The upside-down T symbol on the meter instructs you to calibrate with the meter in the same orientation as you have pictured -- down in the picture is gravitational down.

[heaventwig]

Ugh, okay, this ammeter is mounted flat, which is clearly incorrect mounting, and the wires it's tied to are where they are. So maybe we need to replace the ammeter?

[heaventwig]

But without gravity, the needle should deflect more toward upright, not less, which means the measured amperages (6mA at most) might even be overly optimistic readings of the current drawn by this laser tube.

[DaBlender]

Can we verify with known amperage or multimeter?

[Hurricos]

We sure can, though it'd be easier to do if the ammeter were removed from the circuit. My guess is the ammeter is fine and well-calibrated, so we should defer this.

[DaBlender]

Eventually I think I’ll just build a meter with LCD and logging watching for spikes and measuring decay. Prob integrate with pot to keep at desired levels. Digital would be amazing to nail down settings. A tiny lcd meter is under $10. Not terribly important but I do plan on upgrades. Camera. Plotter and pen cutter ability. Dry erase is actually very very fun. Easy way to teach gcode. Ty for info on orientation that is a cool fact.