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CircuitSetup / Split-Single-Phase-Energy-Meter

Split Single-phase Energy Meter
https://www.crowdsupply.com/circuitsetup/split-single-phase-energy-meter
MIT License
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No AC adapter available #52

Closed eavyon closed 3 years ago

eavyon commented 3 years ago

Because of EU regulations I'm told that AC/AC adapters aren't allowed to sell here anymore. That leaves me to using an AC transformer.

Is there any difference between an transformer and a nicely made adapter? Can I safely connect a transformer to the board or do I need to add some protection? What is the minimum current for operating the board without a esp?

I've already ordered 2 sets for solar monitoring so I hope I can get it to work and post results.

CircuitSetup commented 3 years ago

Any AC to AC adapter is the same as an AC transformer. The point being that you're taking an AC voltage and bringing it down to a much lower level. For the EU, this is usually 220-240V. The transformer needs to bring down the voltage to between 9 and 12VAC.

As long as the transformer you found does this, it should work fine though. It will need to be calibrated to the meter according to the instructions here.

eavyon commented 3 years ago

I scavenged a normal AD adapter and removed the rectifying part. It's measuring about 14v open circuit. I'll update when I have the set tested and calibrated.

CircuitSetup commented 3 years ago

Are there still a bunch of capacitors in there? If so, this will not work very well for reading the AC signal, and could be very inaccurate, depending on how much the caps are smoothing the signal. It doesn't sound very safe either. I would recommend just finding a regular AC transformer.

eavyon commented 3 years ago

I've removed the capacitors and diodes from another 9v 600mA adapter and what is left is the transformer. It measures 10.4v open circuits and dips to 10.2v AC when the board is working. This setup is running now for the last 2 days without problems.

I think this is a simple solution to get a AC adapter so you don't have to deal with a bare transformer without a case.