Re: 555 2n3055 was:The incredible inedible ignition coil

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "butt head by way of Terry Fritz <twftesla-at-uswest-dot-net>" <mrnobody41-at-hotmail-dot-com>

I have used the TIP3055 a slightly smaller version,in a TO220 case,driven 
directly by a 555,and a 100 ohm resistor..Has been driving an ignition coil 
for over a year now..No problems yet..
http://www.users.qwest-dot-net/~ptaylor/zapomatic.htm


>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: 555 2n3055 was:The incredible inedible ignition coil
>Date: Sun, 25 Feb 2001 11:43:56 -0700
>
>Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-uswest-dot-net>" 
><jimlux-at-earthlink-dot-net>
>
>555 can put out around 100 mA
>2n3055 has a gain of about 10 at 5A collector current (meaning you'd have 
>to
>source 500 mA into the base)
>
>3055's may be cheap, but they're not all that great a transistor: low gain,
>low BVceo, awsome thermal runaway, etc..  There are many, many parts that
>are better and still under $1.
>
>
>----- Original Message -----
>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: <tesla-at-pupman-dot-com>
>Sent: Sunday, February 25, 2001 9:06 AM
>Subject: Re: The incredible inedible ignition coil
>
>
> > Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
><Fucian-at-aol-dot-com>
> >
> > In a message dated 2/24/01 7:15:55 PM Eastern Standard Time,
>tesla-at-pupman-dot-com
> > writes:
> >
> >
> > >
> > > There is a problem with the 555 timer plus 2N3055 route. The 2N3055
>actually
> > > needs quite a bit of current to drive it into conduction, and the
>standard
> > > 555 timer is running at its limit, it is better to use a darlington 
>pair
>in
> > > this configuration, or a power mosfet. The 555 plus 2N3055 may work 
>for
>a
> > > time, but the chip may burn out at any time.
> >
> >
> >
> > WOW!!!!!!Thats the answer to my 555 ic probs!Ive been losing them in
>handfuls
> > with no explanation.Now i read the 2n3055 is the prob!No wonder theu all
>died
> > after a few MINUTES!
> >
> > matt
> >
> >
> >
>
>
>

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