Nokia’s banana phone from The Matrix is back | Circuit Breaker Parts

While if we take the same supply and drive it with 300 volts DC, then it will only need a bit less then 4 amps. And this is in fact going to put our rectifier under less load then when we run it with 110 volts AC.

For every piece of equipment that lists MOCP and MCA, you are given the breaker size and minimum wire ampacity. As above, the MOCP is usually significantly higher than the MCA, but this is to allow for the spike in amp draw upon motor start.

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.

Once upon a time, must have been 13 or 14 at the time, was doing the annual find the blown bulb in the christmas tree lights. Must have completed said mission and marvelled how the bit of cable at the middle/end of the lights was hidden within insulation tape (lights must have been 20 or so years old, this was in the 90s) and the curious being that I am thought let’s see what the tapes hiding – obviously bare wires.

My busy season is when people are spending their tax returns and spring-cleaning, but I’m slower in the winter months leading up to that. Call me then, and I might be able to offer you a lower rate if I’m desperate for business.

Interesting how both the sounds and the letters on a QWERTY keyboard for V and B are close enough that it’s possible to switch them by accident.

A decent quality electrician’s screwdriver will have its insulation voltage rating stamped on its handle, though the absence of a rating is not necessarily a reason not to use it. A lot of screwdrivers have first-rate insulated handles, but without a voltage rating because they are sold for general-purpose use rather than specifically electronic. When you choose a screwdriver or other tool, consider the amount of plastic it puts between you and the metal, and pick accordingly. Wooden handles may not provide adequate protection, and metal handles should be avoided at all costs.

This plate is too likely to touch the user. It’s sensible to have a certain fear of mains voltages, makes you pay attention when you’re working with it. The DC power suggested would come from the printer’s existing PSU, pay a little bit extra for a few more amps, the overall wattage isn’t high. Much less than I presume you’d use in industry. Thanks to power-hungry graphics cards, high-power PC PSUs are cheap.

You are right, FR-4 has a glass transition temperature of around 120°C, so if you heat up your traces above that, and take into account the mechanical stress from expanding copper traces, delamination is something waiting to happen sooner or later (especially if you design corners in your traces). Add to that the fact that you usually don’t measure the temperature directly on the traces to regulate input power, you could go way beyond 120°C in your copper traces. I don’t think a lot of DIY guys actually know that there would be high-TG materials on the market better suited for PCB based heater applications…

Actually, while HDR is the more glamorous feature, Sony’s Dynamic Range Optimizer (DRO for short) deserves some attention, as I found myself relying more on it than HDR to manage tonal extremes. Most every camera company has some sort of an exposure mode that adjusts exposure and/or contrast to help avoid blowing highlights or plugging shadows. After several years of tweaking, I think that images shot with Sony’s DRO now look better than most. DRO defaults to the Auto setting on the Sony A33 and A55, and most times I checked, I liked the tonal balance of photos shot that way over that those with DRO turned off.

Once upon a long ago I was tuning a Tesla coil I’ve built with a friend. The coil was driven by a dirty cheap spark gap made with a screw that had to be rotated to change the distance between electrodes. I had to switch off the 6kV primary transformer, ground the terminals and rotate the spark gap, repeating this procedure until the biggest possible spark jumped out of the coil. After repeating it many times, I accidentally forgot one step. I’ll never forget that moment. My arm was thrown in the direction of the wall as if it had its own will and wanted to get through. Not good. Very painful.

http://www.mikeholt.com/technical.php?id=grounding/unformatted/GroundResistance&type=u&title=Ground%20Resistance%20-%20It%27s%20Not%20What%20You%20Think%20%2812-30-99%29