When I originally built myZVS driver that I used with the Jacob’s ladder, I wanted to try and use it as an induction heater. I wound a quick coil out of some solid core wire, but the atx power supply that I was using couldn’t keep up. It kept shutting off. So I finally ordered a variac and put together a quick three component power supply with a bridge rectifier and two filter caps.

I ran across an interesting post about a simple AM broadcast regenerative receiver and thought I’d have a go at building it. Here is the original post http://imgur.com/a/JpwJs. The basic schematic is: I started with a ferrite rod that I had from an old broken AM receiver. I wound 60 turns of magnet wire that will form part of the tuned circuit with the variable capacitor. According to the original post, should measure about 240 uH.

var playerElement = document.getElementById("player-wrapper-vid1"); var player = new Clappr.Player({ source: "/videos/jl.webm", mute: true, height: 360, width: 640, loop: true }); player.attachTo(playerElement); I cleaned out the junk room this weekend and found two old tube tvs, so I cracked them open and salvaged the flyback transformers. (If you do this, make sure to discharge the tube before messing around inside the TV.) It was a rainy weekend so I was stuck inside, so I decided to make a Jacob’s Ladder out of one of the flybacks.

For the next step in decreasing the chances of killing myself, I’ll be making an isolation transformer. An isolation transformer is a 1:1 transformer where the output is not referenced to ground. So if an isolation transformer is connected to mains, then the output should be 120 volts. You could theoretically touch the live wire (don’t do that) since it is not referenced to ground, so there would be no “return path”, but if you were to touch both hot and neutral, you would get a shock.

Some of my recent projects have had me tinkering with AC mains voltage more than usual, so I figured it is time to get serious about my bench safety. My plan is to build several pieces of equipment that should decrease my chances of killing myself. First, I will build a fused gfci power source that will trip if I do something stupid. Next, I’ll build an isolation transformer and then a current limiter.

During my previous project, the slayer exciter, I kept blowing transistors trying to pump too much current through them. While I was troubleshooting the circuit, I needed a quick way to test the transistors I was using, so looking around, I found this simple transistor tester circuit using a 555 timer. The 555 drives the transistor in order to blink the led. If the led is full on or off, then the transistor is dead.