LabBook: Project TouCans on/off relay a bit further along

Over the weekend, KOTBTY and I got to spend more time moving the CW key relay inside Project TouCans and adding a power on/off latching relay. As you can hear and see in the video below, the latching relay is up and running! Thanks for Simon Willison for the Claude artifact that enabled me to easily package up the video below.

Ha, that's interesting! It's not so much a video packaging as a video thumbnail tool, which is of course what it said it was. Well, here's the video all bundled up into an iframe ready for your viewing—and listening—pleasure. I'll have to work with the gang on a version of the tool that outputs iframes soon.

What you can see in the video: the Darlington array has two control leads coming into it from the PICO-Ws GPIO 17 and GPIO 18 pins, (the orange and red wires respectively.) Now that we're using a latching relay, we need one control wire to latch the power on and a second wire to latch the power off. Positive rely coil power is attached directly to the latching relay, but the circuit through each coil to ground is broken by the Darlington array. When the Pico-W signals to the Darlington array to conduct for a fraction of the second, the appropriate relay coil, (either power-on or power-off), is energized and then the connection is latched by the internal latching magnets of the relay.

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