Re: lifter power supply (fwd)

[Steven Roys <sroys@xxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 25 Jul 2003 19:41:6 -0400
From: Wall Richard Wayne <rwall@xxxxxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Cc: rwall <rwall@xxxxxxxxxxxxx>
Subject: Re: lifter power supply (fwd)

Terry

> A 15kV NST will rectify to about 21kVDC.  From what I have read, that
seems
> on the "low end" of voltage needed.

Don't really need to rectify the HVAC.  Either polarity +/- to either
lifter wire produces thrust in the *same* direction. This works with either
HVAC or pulsed DC.  On the rotary lifter I can turn down the HVAC to about
8 KV with a variac and still get thrust.


> A lot does depend on my original question about voltage "above ground".  A
> dual doubler may provide say +20kV and -20kV.  If we "really need" 0 and
> +40kV in relation to ground, the doubler may not be a good choice...  Also
> note that a rectified NST is really -10kV and +10kV at the terminals
> relative to ground which may really be bad...

Forget earth grounding the lifter.  This may be the problem for you.

> "I" am "thinking" we may really need a DC supply that truly does have an
> output about +30kV above earth ground potential.  -30kV, +-15kV, etc. may
> not work...

+/- 15kv should work fine.  See above.  Pulsating DC or HVAC works best.
Regulated HVDC is probably not a good idea.
JLN's most efficient lifter was 70 hz pulsed HVDC.


> An ordinary GMHEI ignition coil circuit may work too.  They are very easy
> to run with a lamp dimmer control.  Plenty of voltage, but I am not sure
> they would have the current needed.  Apparently, lifters need a fair
amount
> of "power" to fly.

I have not tried a GMHEI, but it should work fine.  Lifters use very little
power.  Most of these smaller lifters use much less than a milliamp.
Construction techniques must be meticulous and avoid current leakage.

RWW