[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [TCML] Terry Filter
Hi Paul, Dex, All,
My OBITs are current limited like NSTs. OBITs are designed for even lower duty cycle than NSTs, in that NST are flowing some power all the time they are on, just not at peak voltage. OBITs have power flowing only during the furnace ignition cycle, and they are designed only for indoor operation. This makes their construction possibly less robust than an NST. A prudent person would give them not less protection than they would their NSTs. If you can get them and replace them cheaply enough though, then a terry filter might not be cost justified.
Matt D
-----Original Message-----
From: Paul Brodie <pbbrodie@xxxxxxxxxxxxx>
To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
Sent: Mon, Dec 21, 2009 5:34 pm
Subject: Re: [TCML] Terry Filter
Maybe neon sign transformers are better but I got this OBIT for $20 and I've
lready built 2 neon sign transformer coils and as the Monty Python players
aid, "and now for something completely different!"
So, that said, why do you believe NST's are better than OBIT's? I have no
pinion, having no experience with OBIT's but I have seen them recommended as TC
ower sources many times by many different people. As usual, I'm just being
urious.
Oh yeah, are OBIT's current limited, like NST's or will I have to treat this the
ame as I do the MOT's I have used?
aul
hink Positive
----- Original Message -----
From: Dex Dexter
To: Tesla Coil Mailing List
Sent: Monday, December 21, 2009 15:13
Subject: Re: [TCML] Terry Filter
They don't ,but I wouldn't use OBIT in tesla coil
service.NSTs are better.
Dex
--- pbbrodie@xxxxxxxxxxxxx wrote:
From: "Paul Brodie" <pbbrodie@xxxxxxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Subject: Re: [TCML] Terry Filter
Date: Mon, 21 Dec 2009 12:44:30 -0500
I recently purchased a 9kV 50mA OBIT or at least the seller says it is an
BIT. This appears a little bit hefty for the purpose. Anyway, do these
ransformers require the same sorts of protection that are used with neon sign
ransformers?
Paul
Think Positive
----- Original Message -----
From: Dex Dexter
To: Tesla Coil Mailing List
Sent: Monday, December 21, 2009 05:23
Subject: RE: [TCML] Terry Filter
I run my static gap coil without any filter at all.
NST is 5kv/20ma ,and safety gap is set for
the breakdown voltage of aprox 10 kV peak.
I've never saw it arcing so the breakdown
voltage of my static gap is probably below 9 kV.
Position and way of connecting the gaps with respect to
NST is important.Both gaps should be paralleled with NST.
Dex
--- Gary.Lau@xxxxxx wrote:
From: "Lau, Gary" <Gary.Lau@xxxxxx>
To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
Subject: RE: [TCML] Terry Filter
Date: Mon, 21 Dec 2009 02:16:43 +0000
If you build a filter with MOV's targeting a 15kV NST, and you use a 9kV
ST, the MOV's will allow a peak voltage of something like 22-23kV before they
ick in. With a 9kV NST, the maximum voltage that *should* be allowed is 9000 x
.414 = 12726, call it 13-14kV. So it would be permitting too-high voltages
hat should have been clamped. One needs to select the correct number of MOV's
or the NST voltage used, for the same reason that one needs to set the safety
ap for each situation.
Regards, Gary Lau
MA, USA
> -----Original Message-----
> From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> Behalf Of chipford@xxxxxxxxxxxxxx
> Sent: Sunday, December 20, 2009 8:31 PM
> To: tesla@xxxxxxxxxx
> Subject: [TCML] Terry Filter
>
> I have my terry filter about 50% done. While building it, I asked myself a
uestion.
> Why would a person build anything but a Terry Filter capable of protecting
NST of
> 15,000 volts? I ordered 14 MOV's from dig-key. For 4 or 5 dollars more, I
ould
> have had 16. Now if i want enough for a 15k trany, I gotta pay shipping
> again.Correct me if I am wrong. If I build a Terry filter capable of
rotecting a 15K
> volt trany, I can use it to protect my 9000 volt NST without any
odifications. I bring
> this up because, as we all know, parts get swapped from coil to coil and
f I decide
> to built a larger coil with my 15k trany later on, I could've just moved
t over without
> worry. Am I wrong?
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_____________________________________________________________
Washington DC's Largest FREE Email service. ---> http://www.DCemail.com --->
Washington Online Community Member --->
http://www.DCpages.com
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_____________________________________________________________
Washington DC's Largest FREE Email service. ---> http://www.DCemail.com ---> A
ashington Online Community Member --->
http://www.DCpages.com
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
______________________________________________
esla mailing list
esla@xxxxxxxxxx
ttp://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla