Kojima shows off a new Death Stranding trailer at E3 | 19mm Momentary Push Button

I certain the Residual Current Circuit Breaker is what GFCI is in North America. Not expensive at all for the units that will fit into a device box. The breaker that mount in the breaker panel are pretty pricey though, but are rarely called for. The only time they are needed if a building uses shallow device boxes for some reason.

The Sony A33 uses the image sensor itself when metering, and considers the overall image as 1,200 separate zones in performing metering calculations. Metering modes include Multi-segment, Center-weighted, and Spot, and the metering system can function from -2 EV to +17 EV (at ISO 100 equivalent with an F1.4 lens). An autoexposure lock button is provided, allowing metering to be locked from a specific portion of the subject, then the overall image reframed as desired. +/-2.0 EV of exposure compensation is available, in 1/3 EV steps. The A33 also offers a three-frame exposure bracketing function, which allows a step size of either 1/3 or 2/3 EV between subsequent frames. Shutter speeds from 1/4,000 to 30 seconds are available, as well as a bulb position that holds the shutter open for as long as the shutter release is pressed. Flash X-sync is at 1/160 second. White balance options include auto, six presets (Daylight, Shade, Cloudy, Incandescent, Fluorescent, and Flash), plus both custom and direct color temperature (2,500 to 9,900K) options. The six presets allow +/- 3 step adjustment, and there’s also a color filter setting that provides +/-9 steps of magenta / green compensation.

I have used a setup like this using two back-to-back “door-bell” transformers (220V to 9V) to play with neon tubes when I was a kid. The current was so low that even a lightbulb wouldn’t turn on. However, it was enough to teach me about electric shock from mains voltage when I have carelessly put my finger across the output terminals …

The QD terminals are totally fine as long as you have a ratchet crimper, which I saw you said that you did.

Larger motors used in rural settings and light industry may aswell use 400 voltage between phases by triangle connection. 3 phase 16A sockets are almost never seen in apartments, but are usually found from houses that have garage or other workspace with larger machinery. Larger 3 phase sockets are very common in farm setting and light industrial buildings. E.g. our hackerspace has air compressor that is fed by 3x 400V 25A line. It doesn’t even have neutral line, motor is connected to triangle and 24V for control logic is stepped down from 400V with transformer.

The control circuit for the 12V/24V can be as simple as a MOSFET and don’t even need to be isolated if you know what you are doing. Because you are using a regulated supply, the same heated bed can be used at different countries with different voltages. The safety regulatory stuff get you covered as 12/24V are considered to be low voltage.

Meanwhile in my house (uk) we have a street lamp time switch with a single pole switch that looks like it was designed to handle 30A. It is beautifully engineered from brass that increases the on period as the days get shorter, I felt bad hacking it so that it would turn on my water heater for an hour twice a day, a job it has been doing for 17 years now without incident. Electromechanical is by far the best way for high current loads at any voltage as fatcas I’m concerned.

That works, it’s a couple of hours work with an RFM12B. And it’s write-only, so you can’t read the status (so no confirmation it actually turned on/off).

The other issues aren’t as significant. The copper can be the inner layer like you see in multi layer (3+) boards. The only exposed part can be for the connector and the connector can be made water resistant and closed off.

We recently had a chat among the Hackaday writers about how we could approach this subject. The easy way out is to be all Elf-and-Safety and join the radioactive anthrax crowd. But the conclusion we came to was that this site is a resource for hackers and makers. Some of you are going to lift the lid on boxes containing significant voltages no matter what, so we thought we’d help you do it safely rather than just listen for the distant screams.

Would that we solved with two opto’s per button, one to read and one to press ? Ignoring the LED feature entirely. Because you cannot assign a pin to be both input and output.

Please check Power Integrations LinkSwitch-TN devices:http://ac-dc.power.com/products/linkswitch-family/linkswitch-tn/