I should add to my previous comment re DO-5 and outline drawings...
A 5W "air cooled" diode usually isn't really air cooled. It's cooled by its
leads, in most cases; thus, the Rthj-a is not the formula used for
calculating junction temperature, but rather Rthj-L, where "L" is the lead.
-WB2WIK/6
"If everything seems under control, you're just not going fast enough." -
Mario Andretti
> -----Original Message-----
> From: 2 [SMTP:2@vc.net]
> Sent: Thursday, July 18, 2002 2:07 PM
> To: Steve Katz; W8JI@contesting.com; AMPS; Douglas R Snowden
> Subject: RE: [Amps] Bias Zener Diodes In Parallel ?
>
> In the Digikey catalog, 5w zeners are axial-lead air-cooled devices.
>
> >
> >
> >
> >
> >> > [Steve Katz] Hi Rich. Case temp of a DO-5 stud,
> >>
> >> I have never seen anything smaller than 10w in a stud mount. 3A axial
> >> lead rectifiers are in a DO-5 case.
> >>
> > ??? Not sure what you mean, here. The DO-5 zener devices I use are
> >normally rated 50W at 55 degrees (C) Tc. Readily available from many
> >sources for a few dollars. The advantage is their high peak current
> rating,
> >usually hundreds of Amperes for a low-value Vz. 3A axial lead rectifiers
> >aren't DO-5, they're usually DO-2, DO-41, DO-42, etc.
> >
> > -Steve WB2WIK/6
> >
> >
> >
> >> - R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
> >> www.vcnet.com/measures.
> >> end
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>
>
> - R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
> www.vcnet.com/measures.
> end
>
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