Re: PIRANHA-III Power control? (High resolution digital dimmer schematic) (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Gerry Reynolds <greynolds@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Mon, 18 Dec 2006 20:44:45 -0800
From: huil888 <huil888@xxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: PIRANHA-III Power control? (High resolution digital dimmer
    schematic)

The file at the chipcenter archive 
(http://archive.chipcenter.com/analog/tn046.htm.) was apparently scanned at 
low resolution and converted into a .GIF file. Many of the component values 
are illegible.

The original ON Semi application note is at: 
www.onsemi.com/pub/Collateral/AND8011-D.PDF, and is perfectly legible.

Regards,
Scott Hanson
----- Original Message ----- 
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Monday, December 18, 2006 4:27 PM
Subject: Re: PIRANHA-III Power control? (fwd)


> Original poster: Gerry Reynolds <greynolds@xxxxxxxxxx>
>
>
>
> ---------- Forwarded message ----------
> Date: Mon, 18 Dec 2006 16:13:00 -0700
> From: resonance <resonance@xxxxxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: Re: PIRANHA-III Power control? (fwd)
>
>
>
> This turned out to be a horrible tech note.  When printed out, even with
> just trying to read it before printing, the values are blurred so bad they
> are not decipheriable.
>
> Dr. Resonance
>>
>>
>> ---------- Forwarded message ----------
>> Date: Mon, 18 Dec 2006 10:25:39 -0700
>> From: resonance <resonance@xxxxxxxxxxxx>
>> To: Tesla list <tesla@xxxxxxxxxx>
>> Subject: Re: PIRANHA-III Power control? (fwd)
>>
>>
>>
>>
>> At present we are working on a similar circuit to eliminate variacs.
>>
>> We plan on using a series choke with the MOT primary.  We are winding up
>> some 2 inch ID x 18 inch long PVC pipe filled with cut 1/8th inch dia.
>> steel
>> rods to add a small inductance to clip off the harshest peaks on the
>> inrush
>> current.  We plan on using one in each MOT primary.  Unlike Terry's
>> circuit,
>> we our using a single MOT running around 16-18 Amps each running off a
>> separate 120 VAC circuit --- shooting for a 4.0 to 4.4 kVA total input
>> into
>> the system.  We are shooting fgor 7-7.5 ft long sparks on a portable coil
>> that can run on two separate 120 VAC circuits and not require 220 volts
>> for
>> portable operation at schools, etc.
>>
>> Brian V. is working together with us on this project.  I also want to
>> eliminate the necessity of using heavy variacs for current control.
>>
>> This posted opto-isolated circuit might prove to be the best answer as it
>> is
>> totally independent of the AC line for triggering.
>>
>> I will advise on how it works out.
>>
>> Dr. Resonance
>>
>>
>>>
>>> Here is a "A High-Resolution Digital Dimmer" based on the 555 timer.  It
>>> looks very nice.  I'm inspired!
>>>
>>> http://archive.chipcenter.com/analog/tn046.htm.
>>>
>>> Again the TRIAC driver stage is opto isolated(MOC3022), which is aways a
>>> benefit in HV systems, but in reality how much is this going to help
>>> defend
>>> against a 1MV strike?
>>>
>>> Of course the challenge would be adapting the output stage to cope with
>>> inductive loads.  The consensus seems to be the use of a snubber circuit
>>> (cap + mov), other filters and a healthy amount of capacity over-kill
>>> i.e.
>>> TRIAC rating of *5 voltage and *2 current of values seen.
>>>
>>> I cant really see the EM switching emissions being a problem in this 
>>> case
>>> :)
>>>
>>> Chris R
>>>
>>>
>>>
>>> On 12/17/06, Tesla list <tesla@xxxxxxxxxx> wrote:
>>>>
>>>> Original poster: Gerry Reynolds <greynolds@xxxxxxxxxx >
>>>>
>>>>
>>>>
>>>> ---------- Forwarded message ----------
>>>> Date: Sun, 17 Dec 2006 14:16:41 +0000
>>>> From: Chris Rutherford <chrismrutherford@xxxxxxxxxxxxxx>
>>>> To: Tesla list <tesla@xxxxxxxxxx>
>>>> Subject: Re: PIRANHA-III Power control? (fwd)
>>>>
>>>> Hi All,
>>>>
>>>> Having briefly looked on the Internet the system described at the link
>>>> below
>>>> looks like it might be useful.  Although it has 4 channels, you could
>>>> use
>>>> one channel for each of your 2 MOTs, or even a parallel series
>>>> combination
>>>> using 4 MOTs.
>>>>
>>>> http://www.epanorama.net/circuits/dimmer4.html
>>>>
>>>> I think the key to these designs is the linking the PWM ramp voltage
>>>> timing
>>>> to the mains phase.  i.e. The ramp starts when the mains is at 0v and
>>>> allows
>>>> the output stage to conduct until the ramp voltage reaches the trigger
>>>> voltage and then stops conducting, that way you basically allow the
>>>> mains
>>>> to
>>>> conduct for x% of each cycle.  This may help minimise 'distortion' on
>>>> your
>>>> power line feeding the MOTs.  You could probably use a 555 circuit or a
>>>> digital counter/comparator/ ADC circuit to produce the ramp.
>>>>
>>>> Thanks
>>>>
>>>> Chris R
>>>>
>>>>
>>>>
>>>> On 12/17/06, Tesla list <tesla@xxxxxxxxxx> wrote:
>>>> >
>>>> > Original poster: Gerry Reynolds < greynolds@xxxxxxxxxx>
>>>> >
>>>> >
>>>> >
>>>> > ---------- Forwarded message ----------
>>>> > Date: Sat, 16 Dec 2006 19:08:32 -0700
>>>> > From: Terrell Fritz < terrellfone@xxxxxxxxxxxxxxxxxxxxxxx>
>>>> > To: Tesla list <tesla@xxxxxxxxxx>
>>>> > Subject: PIRANHA-III  Power control?
>>>> >
>>>> > Hi,
>>>> >
>>>> > I am working on PIRANHA III issues today.  A dual MOT system that 
>>>> > runs
>>>> off
>>>> > a 120VAC 20A circuit with ease.  It is in the 8 foot arc to ground
>>>> > range...  About 2kW input at ~90% efficiency.
>>>> >
>>>> > These coils like to run with the MOT input voltage at about 95-105
>>>> > volts
>>>> > to
>>>> > stay out of the MOT saturation range which just waists precious
>>>> > current.  Normally that is done with a 15 -20 amp variac...
>>>> >
>>>> > http://drsstc.com/~piranha/PIRANHA/PIRANHA-3/PIRANHA-III-001.gif<http://drsstc.com/%7Epiranha/PIRANHA/PIRANHA-3/PIRANHA-III-001.gif>
>>>> >
>>>> > Variacs are very nice, but they are real heavy and not real "modern"
>>>> > or
>>>> > solid state.  The charging circuit (MOT / Primary Cap loop) is
>>>> > resonant
>>>> > too
>>>> > to drive up to a 15000 volt firing voltage...  But the waveforms are
>>>> > pretty
>>>> > "tame" and the power factor is excellent without any fiddling.
>>>> >
>>>> > http://drsstc.com/~piranha/PIRANHA/PIRANHA-3/PIRANHA-III-002.gif<http://drsstc.com/%7Epiranha/PIRANHA/PIRANHA-3/PIRANHA-III-002.gif>
>>>> >
>>>> > It would be super cool to use a beefy lamp dimmer circuit or some
>>>> similar
>>>> > cheap but very reliable solid state thing to control power other than
>>>> the
>>>> > variac.  The PIRANHA input section is very forgiving of sloppy input
>>>> wave
>>>> > forms and all so no big deal there.  Ceiling fans are made for
>>>> > inductive
>>>> > loads...
>>>> >
>>>> > I don't know much about dimmer circuits and such so I can't guess at
>>>> what
>>>> > to do and feed the computer models well.  0:-|
>>>> >
>>>> > If anyone knows what to do to make a cheap hardy dimmer type circuit
>>>> that
>>>> > could run two MOTs (~2kW)  I am all ears ;-))
>>>> >
>>>> > Cheers,
>>>> >
>>>> >         Terry
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>>
>>>>
>>>>
>>>
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