How To Wire A New Garage For Electric-Car Charging: What You Need To Know | Lrd12 Overload Relay

The focus voltage on a CRT can wake you up. The shock may not kill you, but falling backwards over a stool can break a limb. I remember working with some Japanese colleagues a long time ago on color displays for IBM mainframes. A young Japanese guy had been sent over to watch our testing and make notes. He didn’t speak a word of English, and to be honest we didn’t warn him very well that the bared card on the tube neck he was investigating was live, and then some.

If you know the Wattage of the transformer and the input voltage of the oven then you can calculate the approximate current the primary (thicker wire) can carry. Example: 500W 220V gives 500 / 220 = 2.273 Amps. This is the current the coil is designed to carry, and this current should normally take the core close to saturation without generating too much heat. The coil resistance can be measured and an appropriate DC voltage applied. I suggest a current of around 1.5 times as long as the power is not ON permanently. Regarding the use of both coils, the secondary coil is much finer wire and will require a proportionately higher voltage. Assuming the output voltage to be 2500, then the current required will be 500 / 2500 or 0.2 A. The secondary coil has worse properties for dissipating heat, so I would only allow a 25% over current, but just try it and if it gets too hot to hold, reduce the voltage. Allow 20 minutes for the coil to cool between tests. Putting the coils in series, or in parallel does not make sense because they have such different characteristics: better to find two ovens with the same transformer and use both primary coils or both secondary coils, which can then be connected in series to raise the working voltage or in parallel to keep the voltage down but double the current. As someone has already said above, disconnecting the coil produces a spark, that in the secondary coil will be a very high voltage – use a totally enclosed switch rated at at least 250V 10 A, with a 100 Ohm resistor in series with a 0.1 microfarad capacitor across the coil to reduce the sparking and increase switch contact life.

A mains isolation transformer. wdwd [GFDL], via Wikimedia CommonsAn isolation transformer isolates the mains supply from the earthing system. This does not change any of the risks inherent to the mains voltage or other high voltages in your device, but it does provide you with some level of protection should you accidentally provide a path to earth from a live component.

Video capture is an area where the Sony A33′s translucent mirror technology makes a huge difference relative to pretty any other SLR currently on the market, and relative to even fast-focusing SLDs. Every other interchangeable-lens camera currently on the market either doesn’t autofocus at all when recording videos, or has to resort to slower and/or more obtrusive contrast-detect focusing. Because the Sony A33′s phase-detect AF system is always looking at the subject, fast autofocus during video recording is no problem.

I like the idea, but you don’t need a 3D printer for this. Just use conductive strips or good ol’ fashioned wire.

Here I have always wondered. If the power bill is such a concern, then why not buy a heat pump for water heating instead? (It drawn typically around half to a third of the power to give the same heat output.)

hmm, not sure why my comment went in the wrong place. looked like it was in the [ GuruBuckaroo] comment, when I pecked it in. The “unusual sensation” quip was spot on & funny!

I first thought we were about to see the actual moment when it was about to blow. But this is post mortem autopsy.

Yes you are correct, I was remembering from just people recommending power USB power supplies, but looking at the latest data, it seems that current is always less than 215mA. That chip looks good.

8 or 12 is usually less than level 2 installations. As I mention they are cool running and very safe. I dare anyone to find a 2012 Tesla MC charging at 40 amperes to say it is ‘cool running’. If it was very hot at the authorized Tesla Service Center, that is all I need to know.

24v 12a is not that much more at 288watts. I’m sure I’m missing something to do with electromagnetism which makes the secondary unnatractive?

Knocking over a candle would be an accident. Keeping barrels of petrol in your living room would be negligence. Doing your own mains wiring without the proper qualifications, I dunno which side that falls on. Real accidents can’t be foreseen, but you have to take reasonable precautions.