Re: MOV's

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Shaun Epp <scepp@xxxxxxx>

Paul,

I've read that TVS diodes conduct quicker that MOVs do,  although I don't 
remember where I say it.

For the Terry fiter, I doubt that you'll find 1800v TVS diodes.  I think 
you'll be stuck with MOV's in that application.

Shaun


----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Tuesday, May 03, 2005 6:25 PM
Subject: Re: MOV's


> Original poster: "Paul B. Brodie" <pbbrodie@xxxxxxxxxxxxx>
>
> Terry,
> Thanks for the info. I went to that site and read all they have on TVS's. 
> From what it says, a TVS is much more like an MOV than a zener and in 
> fact they refer to a TVS as "a clamping device like an MOV." It says that 
> a TVS will clamp a transient at the clamp voltage and divert it away from 
> the device being protected. That was basically what I was asking in my 
> original post. The schematic I have for driving an ignition coil with a 
> Mosfet shows a 130V MOV across the DS of the Mosfet to "protect the Mosfet 
> from transients." (note on the schematic) What I would like to know is if 
> I can substitute one of these TVS's for the MOV in this application?? The 
> TVS is rated 135 to 150 clamp voltage and the schematic calls for a 130V 
> to 150V MOV.
>
> Also, if a TVS conducts at its clamp voltage and stops conducting when the 
> voltage drops below this level, isn't this basically what an MOV does? 
> Could I substitute the TVS's for the MOV's in the Terry Filter?
>
> Finally, I Googled the part number that Electronic Goldmine is using and 
> the only reference I got was Electronic Goldmine!!! I looked at the part 
> at Digikey and I don't see where it refers to this part from Elec Gold. 
> How did you come up with the Digikey part and where do you find 
> information like the Protection Notes you directed me to? If I could 
> figure out how to locate this information for myself, I wouldn't have to 
> annoy you so much!!!{:-) I don't mind doing my own research at all but it 
> seems that all I ever accomplish is to frustrate myself by finding zilch!
>
> Thank you so much for your patience with me. I really do appreciate it 
> more than I can say. You have been a really big help. Later.
> Paul
> Think Positive
>
>
> ----- Original Message -----
> From: "Tesla list" <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx>
> To: <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx>
> Sent: Tuesday, May 03, 2005 1:34 PM
> Subject: Re: MOV's
>
> > Original poster: Terry Fritz
> <<mailto:teslalist@xxxxxxxxxxxxxxxxxxxxxxx>teslalist@xxxxxxxxxxxxxxxxxxxxxxx>
> >
> > Hi,
> >
> > It is a transient voltage suppressor:
> >
> >
> <http://www.protekdevices.com/appnotes/protektion%20note%202.pdf>http://www.protekdevices.com/appnotes/protektion%20note%202.pdf
> >
> > http://dkc3.digikey.com/PDF/T052/1140.pdf
> >
> > Not a MOV or Zener since it is made much differently.  But it works much
> > like a Zener.
> >
> > Cheers,
> >
> >         Terry
> >
> > At 07:44 AM 5/3/2005, you wrote:
> >>The Electronic Goldmine has a "diode" R2MLF-A1 that is described as an
> >>"overvoltage protection diode" that is "designed to clamp at 135 -150V."
> >>Reverse current is 1A. My question: Is this, or is it the same as, 
> an >>MOV?
> >>
> >>I have a schematic for driving an ignition coil with a Mosfet that 
> shows >>a
> >>130V MOV across the DS of the Mosfet. Would this suffice?
> >>
> >>Paul
> >>Think Positive
> >>
> >
> >