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Re: [TCML] "Lifter" power supply questions
The principles of lifters are understood enough to use ion engines in space.
Simply put, air is ionised and attracted from the corona electrode wire to
the corona-less skirt. The mass movement of air under a lifter is enough to
blow out a candle.
They work with either polarity but you will get much more corona from a
point source with negative polarity.
It is not amazing that both polarities work.
This would suggest the upper wire electrode might have best performance when
negative.
http://en.wikipedia.org/wiki/Corona_discharge
I believe the greatest corona in total would be generated by a duty cycle of
100% (ie DC) rather than pulsed.
Peter
http://tesladownunder.com/Lifters.htm
-----Original Message-----
From: stork3264@xxxxxxxxxxx
Sent: Friday, January 14, 2011 9:22 AM
To: Tesla Coil Mailing List
Subject: Re: [TCML] "Lifter" power supply questions
Hi PBT,
I have made several rotary lifters powered by NSTs. Place a HV cap across
the NST HV outlets. A NST by its self won't work. You can also add a HV
diode(s) that rectify the output of the NST for experiments. Personally, I
feel pulsating current gives better performance. Amazingly + or - pulsating
DC makes the rotor turn in the same direction of rotation, but the speed
changes with different polarities. I demonstrated all this at R. Hull's
Teslathon years ago.
Filtered/regulated HVDC is not necessary for lifters. I think that HVDC
corona leaks off the lifter and creates small rapid voltage pulses. So, it's
not really pure HVDC at the lifter electrodes. I also believe there is a
role for pulsating current in the lifter. Perhaps more important than
pulsating HVDC. Maybe the HV cap is responsible for current pulsation.
Anyway, the interest in lifters seems to have waned considerably without the
true mechanism defined. I hope you find it.
Stork
----- Original Message -----
From: "Peter Terren" <pterren@xxxxxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Thursday, January 13, 2011 7:07:55 PM
Subject: Re: [TCML] "Lifter" power supply questions
Hi PBT
None of these will work as none are pure filtered stabilised DC at a current
of perhaps 100uA.
You should do what almost everyone else does and use a TV monitor with the
HV wire brought outside. The voltage is borderline at 25kV but should be OK.
The 100kv supply is an AC induction coil with the pulse mostly in one
direction. It is not true DC and being pulsed will only provide lift for a
small part of the cycle.
Rectification probably won't help much. Same with ignition coils.
van der Graaff's and static machines aren't stabilised and will struggle to
get the current.
NST's are AC and might work with a dual voltage doubler arrangement to get
30kv DC and series resistor to prevent burning up with flashovers.
Cheers
Peter
-----Original Message-----
From: mrapol@xxxxxxxxxxxx
Sent: Thursday, January 13, 2011 11:53 PM
To: Tesla Coil Mailing List
Subject: [TCML] "Lifter" power supply questions
Hello,
I am working on a high voltage "lifter," and I have some questions about
powering it. I checked the list archives and found some info, but nothing
that addresses my particular questions. Any clarification would be
appreciated.
Most of the how-to stuff I have read supposes you're building a power supply
from scratch, adapting a flyback, etc. I have a variety of HV sources:
--a 100 kV DC variable power supply, made by Hamilton Drills of Canada.
(These are commonly sold on eBay. They appear to be solid state induction
coils, rectified to give DC output? The maker insists they are DC, although
he does call them "Tesla" coils too . . . )
--various NSTs in voltages of 7.5kV, 12kV, and 15kV, at 30 and 60 mA
--an OBIT (10kV, 23 mA)
--auto ignition coils driven by household dimmer switches
--a Van der Graaff generator
--a hand cranked Wimshurst machine
My question is, nowhere have I found what would be needed to hook up an
existing power supply to the lifter. From what I read I assume the Hamilton
Drills unit is the most suitable, but simply connecting the lifter to the
output posts does not seem to work. An email to the Hamilton Drills maker
yielded a reply that I need to connect two 75kV, 5mA diodes (?) in series to
the unit's output--presumably the + terminal?
From what I read on the list archives, it is possible to use AC sources
like
NSTs? My big question, having power supplies and having made a lifter, what
is the best way to hook them up?
PBT
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