Sunday, 18 December 2011 06:22


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This power supply was built along the lines of the VK4EU schematic on this web site.

VK4EU is one of the founding members of the club.

Some variations were employed in the build up due to the large amount of amperage available.

WATT THA as it is known is a 3.9KVA power supply all this is available if the A/C was three phase as the input would be re-configured.

At present settings it has been tested to100+ APMS across 4 x 12 volt batteries for 4 seconds these batteries remained charged for 3 months and no smoke wow.

The transformer has dual windings on the output 1/2 inch in width each and 1/8 of an inch thick (out puts in total 4 2pos 2 neg)
This can be seen in the pictures

The smoothing caps are 22000uf each by 10 of = 220,000UF close to ¼ of a farad, one would suggest ample smoothing of the DC

There is a 10 AMP AC circuit breaker on the input.

A 70AMP circuit breaker on the DC output compliments of the car sound industry which has been tested and works at 13.8 VOLTS via my THP HL700B into a dummy load of course.

There are 10 transistors capable of 20AMP each to drive up the amperage with another one as a darling ton driver.

This supply is variable total volts out are 26 DC at the transistor pack and uses an LM317K to vary the voltage supply.

4 stud mount rectifier diodes are employed for rectification at 120 AMPS each.

 The AC volts gauge is from a factory that was demolished and the AMP gauge was from the same demolition.

The DC volt gauge was one I had in my junk box picked up at a ham fest somewhere.

The cooling fan is AC from a soccer game where the ball return was air to eject the ball to be used again.

The cabinet was from the original transformer where it served as a forklift battery charger.

One of the tests that were performed was to see the voltage drop at 13.8 at 30 AMPS it was.001 of a volt making it very stable.
 Thank you for viewing my supply as I am quite pleased with the results.

It has been said that the lights dim in my area when WHATT THA is in use or that I should DC power my house HA! HA!

 Watt Tha

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