How KT207 / 400 left

I decided to use this triac for my experiments with 230V. It was a used type from some facility. He already had short leads and certainly many hours of operation behind him. High time to retire… Instead he went to the eternal hunting grounds…..

I connected it to a universal board. I have not connected the voltage to the control electrode yet. He wanted to measure and adjust it first. I also measured whether there is a connection between A1 and G. An alternating current was supposed to go to the control electrode through a 1uF/630V capacitor, resistor 100 ohms, I don't, button and limiting diodes against ground.
After turning on the 230V, it flashed, there was a bang and the circuit breakers in the main cabinet responded….. Now I'm wondering where the mistake was…. It could only be a tin bridge…. I am currently modifying the fuse box so that my circuit breakers don't blow again. I have 230V on this box, I use it to power my 40W soldering iron, there is also a diode in the box, which is bridged by the switch, with which I switch the power to the soldering iron. I have another KT207/400, work on it will start when I find out a few details about how the triac is powered. Alternating current ? – after all, that's probably why the student is there….

In the schemes, in which Tc is controlled, the electrode G is fed mostly to IO – what is the tension there, I do not know. Functionally, the triac is composed of two thyristors, and the thyristors are switched by direct current. Two different thyristors NPNP and PNPN are used in the triac ? In my opinion, two identical thyristors connected in parallel would also work. These would then be switched with direct current. My brother showed me the triac switching diagram, it is powered at 230V directly to the control G via a diac, so alternating after all.

The memorial service is being held today 6.5.2003
Honor his memory.