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Old 20th Oct 2019, 1:09 pm   #24
regenfreak
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Join Date: Nov 2018
Location: London SW16, UK.
Posts: 655
Default Re: DIY battery eliminator for valve radio

The tesla "coilers" have a fair share of IGBT explosions. In double resonance solid state tesla colis, the IGBTs are used for switching the load which is a series LC resonance tank. The switching is timed at the zero-crossings (ZCS)of the load currents to reduce power loss. Any deviation from this soft switching conditions will result in a firecracker like explosion, e.g. parasitic inductance in the circuit that induces voltage spikes.

http://kaizerpowerelectronics.dk/tes...n-guide/igbts/

Going back to the B+ PSU, the series pass regular with negative feedback(two transistors), I meant to copy your rotary switch zener ring arrangement, but i think the momentarily open circuit may generate high voltage pike, so I will stick with simple output tappings.

Last edited by regenfreak; 20th Oct 2019 at 1:14 pm.
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