Which caps for serial com?
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Posts: 46,084
Hi All,
What type of caps do folks like for the programming input on a BS2p,
meaning the 100V/.1uF ones? I'll probably use DigiKey, if anyone has a part
# handy. Through hole mount as small as possible would be ideal.
Thanks,
Jonathan
www.madlabs.info
What type of caps do folks like for the programming input on a BS2p,
meaning the 100V/.1uF ones? I'll probably use DigiKey, if anyone has a part
# handy. Through hole mount as small as possible would be ideal.
Thanks,
Jonathan
www.madlabs.info
Comments
jpeakall@m... writes:
> What type of caps do folks like for the programming input on a BS2p,
> meaning the 100V/.1uF ones? I'll probably use DigiKey, if anyone has a part
> # handy. Through hole mount as small as possible would be ideal.
>
> Thanks,
>
BC1160CT, .1uf, 50WVDC, .100 centers
Sid Weaver
W4EKQ
Port Richey, FL
[noparse][[/noparse]Non-text portions of this message have been removed]
So it is ok to use a cap rated for 50V? What about 35V? I have some tantalum
.1uF/35V caps handy.
Thanks for the help!
Jonathan
www.madlabs.info
Original Message
From: <Newzed@a...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, August 13, 2003 1:13 PM
Subject: Re: [noparse][[/noparse]basicstamps] Which caps for serial com?
> In a message dated 8/13/2003 3:49:54 PM Eastern Standard Time,
> jpeakall@m... writes:
>
>
> > What type of caps do folks like for the programming input on a BS2p,
> > meaning the 100V/.1uF ones? I'll probably use DigiKey, if anyone has a
part
> > # handy. Through hole mount as small as possible would be ideal.
> >
> > Thanks,
> >
>
> BC1160CT, .1uf, 50WVDC, .100 centers
>
> Sid Weaver
> W4EKQ
> Port Richey, FL
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
> To UNSUBSCRIBE, just send mail to:
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>
>
>
jpeakall@m... writes:
> So it is ok to use a cap rated for 50V? What about 35V? I have some
> tantalum
> .1uF/35V caps handy.
>
> Thanks for the help!
>
Jonathan, do NOT use tantalum. One of the caps is for coupling, the other
for by-pass. Use a ceramic or metal film cap that is not polarized. The part
numbers I gave you works well in all my applications.
Sid
[noparse][[/noparse]Non-text portions of this message have been removed]
Jonathan
www.madlabs.info
Original Message
From: <Newzed@a...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, August 13, 2003 1:36 PM
Subject: Re: [noparse][[/noparse]basicstamps] Which caps for serial com?
> In a message dated 8/13/2003 4:34:10 PM Eastern Standard Time,
> jpeakall@m... writes:
>
>
> > So it is ok to use a cap rated for 50V? What about 35V? I have some
> > tantalum
> > .1uF/35V caps handy.
> >
> > Thanks for the help!
> >
>
> Jonathan, do NOT use tantalum. One of the caps is for coupling, the other
> for by-pass. Use a ceramic or metal film cap that is not polarized. The
part
> numbers I gave you works well in all my applications.
>
> Sid
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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Body of the message will be ignored.
>
>
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>
>
>
jpeakall@m... writes:
> Thanks Sid!
>
>
You're welcome, Jonathan. Anytime.
Sid
[noparse][[/noparse]Non-text portions of this message have been removed]
On Wednesday, August 13, 2003, at 04:36 PM, Newzed@a... wrote:
> Jonathan, do NOT use tantalum. One of the caps is for coupling, the
> other
> for by-pass. Use a ceramic or metal film cap that is not polarized.
Maybe you could fill in the blanks for those us who don't know about
tantalum VS. other caps.
Thanks,
Ben
writes:
> Maybe you could fill in the blanks for those us who don't know about
> tantalum VS. other caps.
>
Tantalums are basically electrolytics and as such are polarized. They should
never be used in a circuit where the "positive" lead could be subjected to a
voltage below ground, i.e., any negative voltage. They are normally used as
filter caps in circuits where the voltage is a pulsating DC, i.e. again, where
the voltage never goes below ground. Reverse polarity, if of sufficient
magnitude can cause a tantalum - or any other electrolytic - to explode. If you
look at the tops of aluminum or tantalum caps in the larger sizes, you will see
crossed indentations in the metal top. These are to allow the cap to expand
and vent when reverse voltage is applied and avoid an actual "explosion". This
works pretty well except in cases of extreme over-voltage.
Non-polarized capacitors - ceramic, film, foil - are not polarity sensitive
and they don't care which leads go to ground. This type should be used
whenever a coupling or bypass requirement exists, or in any
frequency-determining
circuit.
I hope this helps.
Sid
[noparse][[/noparse]Non-text portions of this message have been removed]
For A.C. passing audio applications, an electrolytic in the wrong place will
cause asymmetrical current to flow, with awful sounding audio the result.
And those little relief vents on electrolytic caps won't work in a
high-current reversal, which can result in molten aluminum confetti all over
your circuit. The reason why is that electrolytic caps pack a lot of farads
in a small space due to an oxide layer between the two foil segments. This
forms an insulating barrier between the conductive plates which can be is
very thin.... But this oxide layer will short out with any reverse polarity
resulting in catastrophic(!) failure.
Also be aware that for high-frequency switched power supplies, the
jelly-roll winding of a standard electrolytic has too much inductance to
work. So a folded high-frequency capacitor that's usable to 50 kHz or so is
selected for the job. Never substitute a standard electrolytic for a
switcher power supply capacitor. Bad things will happen....
Mike Sokol
Original Message
From: <Newzed@a...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, August 13, 2003 7:12 PM
Subject: Re: [noparse][[/noparse]basicstamps] Which caps for serial com?
> In a message dated 8/13/2003 6:51:26 PM Eastern Standard Time,
ben@c...
> writes:
>
>
> > Maybe you could fill in the blanks for those us who don't know about
> > tantalum VS. other caps.
> >
>
> Tantalums are basically electrolytics and as such are polarized. They
should
> never be used in a circuit where the "positive" lead could be subjected to
a
> voltage below ground, i.e., any negative voltage. They are normally used
as
> filter caps in circuits where the voltage is a pulsating DC, i.e. again,
where
> the voltage never goes below ground. Reverse polarity, if of sufficient
> magnitude can cause a tantalum - or any other electrolytic - to explode.
If you
> look at the tops of aluminum or tantalum caps in the larger sizes, you
will see
> crossed indentations in the metal top. These are to allow the cap to
expand
> and vent when reverse voltage is applied and avoid an actual "explosion".
This
> works pretty well except in cases of extreme over-voltage.
> Non-polarized capacitors - ceramic, film, foil - are not polarity
sensitive
> and they don't care which leads go to ground. This type should be used
> whenever a coupling or bypass requirement exists, or in any
frequency-determining
> circuit.
>
> I hope this helps.
>
> Sid
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
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>
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>
>