ESP8266 Community Forum

- Sun Nov 15, 2015 5:24 pm #34118 I am working on a pcb to fit inside a box with two outlets on. Each outlet is separated inside the box, so they can be controlled individually.


The boxes seems plenty big to house all the electronics, but they are actually only just big enough.


Just a quick test to check if the measurements I did for the devices in Eagle was correct.


Testing it in the box too, which was lucky, because I had some things a few millimeters off, and if I had not found that problem and corrected it, the pcb would not fit in the box.


A few rendered pictures of the pcb from top and bottom

• More info about the project on my blog http://captain-slow.dk/2015/11/14/wifi-switchbox/ where I also will release the source files once I have tested if the pcb works as expected, and fits inside the box.

- Sun Nov 15, 2015 7:59 pm #34139 what do you think of the AC-DC switching power supplies? i've recently noticed them on ebay for < £2. do they get hot, what's the build quality like?

its certainly the smallest way to power the ESP8266 from mains AC.

- Sun Nov 15, 2015 11:25 pm #34148

what do you think of the AC-DC switching power supplies? i've recently noticed them on ebay for < £2. do they get hot, what's the build quality like?

its certainly the smallest way to power the ESP8266 from mains AC.

They are decent build, but I would not use them for something that comes in contact with people. They do get a bit hot when loaded to their max rated current for extended time, but not unusually hot.

- Mon Nov 16, 2015 3:56 am #34170 Hi, a great idea.
I couldn't see any over current protection, you could consider using a fuse or PTC to prevent more than 3A being drawn through the relays. In an ideal world the 120V to 5V converter would have over current protection on its output as well ( I believe this is built in).

Fuse v PTC.

Fuse: slow acting and requires much more than it’s rating to blow, my not protect the relay, but will eventually disconnect the fault. Down side, would require the enclosure to be opened up to replace.

PTC: faster acting and would provide greater protection for the relay. Self-resets, so the enclosure doesn’t need to be opened. Down side, it self-resets. If there is a problem it will keep connecting the power equipment if it is faulty.

NOTE: PTC should never be used on equipment with open moving parts such as a ceiling fan. In the event that the fan overloads the PTC, it will switch off the fan. However when it recovers it will switch fan back on without warning.

I made some single socket outlets (mainly for external LED lighting) with 2A rated SSRs and used:
2A PCT to protect the SSR.
3A fuse to protect the whole unit.