relay board

Mar 24, 2025 Last reply: 1 year ago 8 Replies

Here's another PCB:



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I figured we could have a relay board in our modular power system, and my PCB layout guy had time, so I did one.



Then I figured that instead of fuses to protect the contacts and PCB traces, I could use Hall sensors and drop out a relay if the current exceeds 8 amps. Then I figured I may as well report the currents to users. And why not voltage too? Then it became a programmable circuit breaker module. With average and RMS voltage and current and power measurement and waveforms. And programmable ganging. And plugin fuses for bussing. Somebody stop me.


Better is the enemy of the good

Selling more is better than selling less.

With respect to hardware UIs my heuristic is that number of users who'll use a given feature declines exponentially with the depth of the menu dive they must go on to get to said feature

We don't want complexity to drive away users, which suggests limiting or at least simplifying features.

I think we'll make power metering an extra-cost option, partly for that reason.

If people just want relays, I don't think the circuit breaker function will scare them off. They don't have to use it, and everybody already is used to circuit breakers.

more like enemy of "good enough" aka. done

Done is an important engineering virue.

If a bit of hardware could be applied with some code, it may well be worth putting on a board. Some customer might want a feature and it could be added quickly.

Lots of people make electronic programmable circuit breakers, but generally don't include measurements or waveform acquisition. So why not? I have embarassing amounts of whitespace on this PCB.

I can see how having a record of events prior to the “breaker” opening could be useful.

Good idea. We could act like a digital scope and save data before and after the breaker open trigger. That's a feature. We'll do it.

Thanks

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