[Prev][Next][Index][Thread]
an idea for a cheapie solid state coil
Subject: an idea for a cheapie solid state coil
Date: Thu, 8 May 97 14:17:07 UT
From: "William Noble" <William_B_Noble-at-msn-dot-com>
To: "Tesla List" <tesla-at-pupman-dot-com>
thought experiment - consider the following:
PC power supplies are 65 to 250 watt. Dead ones cost a dollar or two at
swap
meets (what we here on the west call ham fests). They are a switching
regulator. Newer ones switch in the 70 to 300 Khz range which is in the
ball
park for tesla work. A 200 watt supply will output lots of 5V current
(20
amps or more) with smaller amounts of 12V.
Remove diodes for -5, -12 vdc outputs - they won't be needed. remove
diodes
for +12 and +5 and see if the circuit oscillates. (fix until it does).
Sometimes there is feedback from 5V, often a crowbar on 5V.
Once the thing oscillates, take the 5V winding from the Xformer and
bring it
out of the supply and use it to excite a primary coil directly. Adjust
inductance of primary so the supply doesn't go into current limit - you
might
be able to wind a primary (helical) near a 3 or 4 inch dia secondary,
and then
slide some ferrite rods in the bottom to adjust inductance.
Most newer supplies use PWM chip - if you look up the specs on the chip
it
might let you have lots of fun control over what the supply does.