Does Tesla Make The Best Value EVSE For Non-Tesla Owners? | Lrd12 Overload Relay

But if the power supply isn’t made for the 110-120 volt market, then yes, this can be a legit concern.

A couple months back I ran across a note in the datasheet for an inexpensive but reputably sourced power MOSFET that said that, while the die itself was rated for 200A continuous/400A peak the package and its leads were only rated for 125A/250A. So I said to myself “I wonder what the mode of failure looks like?” And built up a circuit to drive it to failure in a controlled manner. It was fairly spectacular: 1) the thermal expansion rate of the die doesn’t match that of the package and once you exceed some wattage tension builds up and (at least in the case of my particular DUT) the chip package literally exploded sending shards of epoxy and/or ceramic flying far and wide. 2) with the die now exposed in several areas and the connection to the heatsink thoroughly hosed by the explosion of the package things devolved rapidly and the magic blue smoke escapes (which smells very bad, FYI, and takes a while to fully purge that smell from the workshop).

I will tell you guys how to dim lights with relays, but first you have to tell me how you dim them when using a zero cross detection optotriac.

Aluminum wire has a lower ampacity than the same gauge copper wire, meaning aluminum must be larger to accomplish the same ampacity job as copper wire. The rule-of-thumb sizes rely on the lowest allowable temperature rating of the wire; in some cases, the circuit may have a higher ampacity if the insulation on the wire and the connection endpoints are all rated at 75°C (167°F) or 90°C (194°F).

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You just described Capitalism in general ….. Every corporation I worked as an engineer for did those exact same things all the time and that was over 20 years ago before China even became a player …. American automobiles in the early 80’s are an even better example

I think that’s technically just thin graphite. Graphene is 1 molecule thick sheets. People were gobsmacked when they discovered you could make it with sellotape.

I had three electrocutions with mains voltage in about one hour. It was a dark and stormy night, when I decided to try again building my own half-bridge SMPS which had tendency to explode whenever I plugged it in. It was made of two boards: one contained EMI filters, bridge, fuse and HV electrolytic capacitors, other had high-side controller, transistors, transformer and everything else. When another transistor decided that it would rather choose new Pope instead of working, I got a bit angry. I grabbed something to drink in kitchen, returned and grabbed the board in order to smash it against the wall. I forgot to unplug it first. Ouch. Half a hour later, it was still dark and stormy night, I attempted to fix an ATX supply. When I was grabbing something from behind of supply, I touched the board with my forearm. Supply was plugged, of course. Ouch. Half a hour later, yes, it was a dark and annoying night, I was still working on the ATX supply. I unplugged the supply and was inspecting the traces, my nose and lower lip brushed solder pads of those two big caps that were charged to ~320V. I went to bed with my face hurting…

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.

I worked in telephony for many years, and the ring voltage can be as high as 180 bolts at various frequencies, but, rather low current. In really old telco systems it may also be a square wave.

Agreed. I work in electronics as a profession. High voltage electronics no less. Industrial size high voltage power supplies. Everything about them up to maintaining them down to component level. The comments here from people are scaring me shitless from the lack of knowledge to the over the top over complication of the problem.

Varistors primarily consist of arrays of zinc-oxide (ZnO) balls, in which the ZnO was altered with small amounts of other metal oxides such as bismuth, cobalt, or manganese. In the MOV manufacturing process, these balls are sintered (fused) into a ceramic semiconductor. This produces a crystalline microstructure that allows these devices to dissipate very high levels of transient energy across their entire bulk. After sintering, the surface is metallized, and leads are attached via soldering.