At the first days of 2016, mentioned about my new relay box in that entry it contains a ssr relay module which can handle 220v voltage with 2amp current. the motivation of building a new box instead using existing one was emf problem, each cycle of relay causing electromagnetic interference and resetting the onboard microcontroller. sounds like not big deal but it's serious when your computer turning on the jukebox at highest audio level and playing music about 3 days while you're out of city. true story.

We're eliminated this issue with a new box but problems are never ending. this time messing with extreme heat. i put an extra relay which can handle upto 220v/10amp for solder and stove, everything was going good until relay melts the plexiglass structure of box.

Solution
I got a small aluminium case laying around there which in exact size of the box, i mounted it by using 10mm screws with one finger distance. plus integrated a micro sized 12v fan for box cooling. such a minor functionality but result is looking like fusion generator

while it's open, i also implemented an AC capacitor to terminals which gathered from a dead hair dryer and guess what, that's completely solved the emf problem. at least it's stable since 5 months.

Usage
So what it does now, it's connected to my home automation software. previously mentioned about air quality sensor, it's measuring the air quality with various sensors. today it's the same device, just redesigned the casing and added connection heads for external PIR sensor same software analyzes sensor values from this device and turning on/off connected appliances based on levels. for example, i don't smoke cigarette even i hate it. if somehow a guest smokes at another room, particle levels in environment increases about 10% and software turns on the air ventilator fan at the wall. same scenerio applies to LPG, extreme deodorant usage and even fart

another example is air conditioning, i survived from whole winter with my small stove. it's enough for 5.5m2 room in our climate area. sofware determining first if there is someone exists in room by pir sensors then launching the stove for 20 minutes if temperature is below 15c.

whole workstation also connected to a portable ups, i created a battery monitoring system afterwards to prevent take any automatic actions. cheap ups systems does not have a usage limiter, we don't want to fry our batteries if got electiricity interruption on stove usage.

Cost
another motivation was production price. maybe not at 2002 but similar devices available on ebay today starting from $100. my total spent resources is:

1x 10A ssr relay: $10
1x 2A ssr relay module (4 relays): $15
5x female electricity outlet: $5
Plexi casing already available but let's say $2

Total spent: $32 + 1week