A Short Guide to Vintage Traynor Amps | 220v Contactor Relay

Some heaters are a coil of Alloy wire cast in ceramic and then enclosed in a stainless steel tube. Basically a bad inductor, but still having the surge properties of one. Same with big boy halogen bulbs.

It may be just perception coloured by the general work environment, but a lot of the US regs seem driven by liability concerns. Too many lawyers.

By not distributing the three wires and only distributing two you try to limit the possible potential between neutral at the sub and neutral at the house by using multiple earths anywhere you can so in this case when lightning strikes the local ground potential rise applies to the ground and to the local end of the neutral/earth wire. Massive currents may flow through that neutral/ground and eventually through the low value resistor at the substation but under no circumstance other than network failure is it possible to get a neutral ground potential of significance with a premise. The low value resistor at the sub limits the current to one that the network can handle.

I don’t know where do you see low voltage traces close to mains voltage. Trace from R8 to the opto is 2.64. How far do you think it should be to meet your standards? Conformal coating is telling you anything?

For example, you can assemble a computer and do anything you want with the low-voltage parts, but opening the PSU and fiddling with that is illegal in many parts of the world. IF the device later catches fire and the insurance company finds out it was modified by yours truly, they can deny coverage, and if your neighbor’s house burns along with yours they can sue you etc. etc.

The list of absolutely required tools is missing the appliance tester. e.g. something like this http://www.fluke.com/fluke/m2en/Products/category.htm?Category=PAT or https://www.gossenmetrawatt.com/english/ugruppe/testingofelectrappliances.htm

When I was doing rehab work on old Chicago apartments I would often find electric wires run through abandoned gas lighting pipes, ready made conduit going to where the old gas light fixtures were, not exactly code and very confusing, especially since there were “live” gas pipes mixed up in the walls and ceilings with the ones carrying Mr. 120!

Dust particles are often flammable, in high densities this means they’re explosive. https://en.wikipedia.org/wiki/Dust_explosion

I am going to try a rheostat on the input voltage to see if I can drop the rectifier output voltage to around 30v. Right now it works but will pop a15A wall circuit breaker after 15-20 seconds. But it is a super strong magnet. Limiting the current is the key I believe. More later

On my printer I closed the sides, took the heated bed off and fitted a relay on the driving wires connected to a travel (230 volt AC) hair dryer screwed to the back. ABS prints like PLA now, no warping or other problems other than the normal ABS shrinkage factor.

When building my printer, I also didn’t like the then state-of-the-art heated PCBs. Thus, I ordered a bespoke silicone heater mat from China, mains voltage, 400 Watts of heater power. Add an aluminium plate to the top and ground it, and safety will be sufficient. I use an SSR embedded into a wall-wart form factor project case with plenty of snubber circuits. Cons: More expensive than a PCB Pros: Heats up incredibly quickly, reasonably priced, won’t get damaged by prolonged high temperature, easy to make non-life-threatening.

Your friend died of what and why? Testing mains voltage across the back of his hand? Please. Mains voltage is not scary if you know what you are about. I dealt with volts up to 132KV and mega amps and megawatts in my career I worked in the UK electrical power industry.