Michał Słomkowski built a pyrotechnic blasting machine using the ringer crank generator salvaged from a military field telephone. Cranking the generator charges a capacitor bank through a bridge rectifier. A thyristor then dumps that stored charge through the pyro filament, melting it and igniting the charge.
The circuit is not just a raw dump-and-fire setup. Słomkowski added a charge indicator using two Zener diodes and an LED, plus a filament continuity tester running a safe, non-triggering current from a 9V battery. The thyristor he chose is a high-current unit, almost certainly a junk-box part, and it is a deliberate over-spec for the job. That design reasoning is worth reading in full.
The project is old but was recently republished on his site, and it carries an uncomfortable observation: bridge rectifiers and thyristors are now harder to casually source than microcontrollers. A device like this, built today, would likely default to an MCU and an AliExpress inverter module. The original did the same job with crank, capacitor, and a single switching component.
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