Power goes out when pc turns on – Components | Lrd12 Overload Relay

It would work, you could try just one winding on its own to start with but beware the voltage surge you get when disconnecting the current, as a minimum it should make a nice spark, even with a small battery driving it, at its worst it is shocking(!) I think the reason for winding your own coils is to get the optimum ampere turns for a chosen voltage, if you use what the transformer comes with you will have to work out what voltage gets you the highest magnetic strength without burning out the winding.

Even with a large heat sink like that, shrink it to 50mmx100mm and the datasheet lists a max of 10A. With that aluminum plate, I’d be surprised if it could handle more than 5A for a length of time.

It’s a great idea but a shame it isn’t laid out correctly, The traces on the low voltage side of the opto-couple are too close to the mains voltage and also the trace from resistor R8 to the opto is too close as well.

I know a lot of people that have never heard about “makers” but I wouldn’t trust them near any mains wiring – like my own dad who has wired a circuit breaker between live and neutral. Only the ensuing BANG and my mom’s swearing and yelling from the now dark kitchen have disabused him of the idea that that is how it should be done.

2. It’s very likely that this device will need to be used with extension cords in order to find two GFCI-free outlets in different phases. That, fundamentally, is why this project is – generally speaking – a bad idea. Still, extension cords can be used safely if you don’t draw too much current through them. The use notes in the article speak to the need to derate circuits appropriately. But that said, the derating doesn’t change just because you pull 240V instead of 120V.

Adjusting settings via the Fn menu is generally a good experience. A very nice touch is that you can use the up/down/left/right directions of the 4-way controller to move the cursor between Fn menu items, and then use the front control dial to adjust the settings. This is nice because it lets you quickly make a number of Fn settings changes in succession, without having to drop down a menu level for each, or being forced out of the Fn menu between choices. The few exceptions to this are those items with a second level of control, such as multi-shot ISO or the tweak adjustments for white balance settings. In those cases, you need to explicitly select the menu item via the OK button, and then use the left/right keys to make the needed adjustment. The only exit at that point is to hit the OK button again, which unfortunately drops you out of the Fn menu entirely.

You did reply to the Gurubuckaroo comment, just a few interjections managed to find their way in first. Does mess up smartarsed replies occasionally, shame when it’s a particularly funny one. On busy articles, I often find posts popping up between pressing “reply” and “post comment”.

It’s still dangerous though. Cost of a 12V power supply vs a small chance of killing myself, I’d spend the money. 3D printers aren’t cheap anyway, why economise on safety?

If you look at the Fotek datasheet for that relay, you’ll find that the specified heatsink does not resemble a piece of galvanized steel sheet metal, horizontally mounted with a half inch air gap under it, and set on top of a heater.

I bought an optically isolated unit that is a “Solid State Relay.” ( SSR)The insides are some kind of zero crossing SCR/TRIAC I’m sure but the key is that the input is a logic signal at a few ma anywhere between 4-30 VDC. This unit is rated to 250VAC at 50 amps. I use it with a foot switch and DC wall wart to turn my welder on and off. It DOES require a beefy heat sink for that kind of power but it hasn’t even broken a sweat (my welder uses around 40 amps give or take.) I would strongly recommend adapting this circuit to take advantage of one of the many available SSR’s out there and let a professionally made and UL certified device handle the mains side. You just drive one of these with the GPIO side here. Of course you can use a much smaller unit for doing the typical 15 Amp light circuits. I actually used such a unit controlled by an Arduino to switch a hot plate (1000 watts) on and off for my flow soldering rig where the Arduino automates the solder temperature profile. I think it is best to marry our “hacks” to these commercial components that have proven performance/certification for our mains. My two cents ‘

I’m wondering why nobody is simply rectifying a 120vac input for dc wiring the secondary coil? It means you don’t have to swap the coil location or use a dc power supply. I have a trans with a secondary resistance of 82ohms. Putting 120vdc through it would be about 175watts (assuming I do a good job of determining wire size and 1.46amps is ok)

Is it possible, that the discreet triplers (vs. diode split transformer) were in the time of BW-TV? They had lower power. Or the guy tested the AC before the tripler, I think that would make a great difference. Although I also would not do this intentionally. There would also be a nice arc to a grounded screw driver, if you want to test the HT – without any current path through myself, what I really prefer. The electrician, whom you mention, did he really die while testing for voltage with his hand, or was his accident unrelated to this?