• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Little switcher for tube filament supply

Marlin Jones has a little switching supply designed for Li battery charging or LED CCS -- $4.95 -- you can adjust the output from 0.8 to 30V @3A (without external cooling) -- measures 1" x 2". Just requires that the input voltage be about 0.8V higher than the output. I have one running 6.3V right now.

Constant Voltage or Current LED or Li Battery Driver/Charger | MPJA.COM

Switch frequency is 300kHz so noise shouldn't be an issue.
Good find, but I'm not sure that I like the way the inductor is mounted
over parts on the board.With it's windings in parallel with the leads on the IC.
Also from the picture, is the copper wire on the coil enamel coated? It
does not look like it is.


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