Selenium Rectifier / Metal Rectifier queries

copper oxide rectifiers don't deteriorate and can withstand an indefinite
short circuit - but in exchange for that ruggedness they have a very high
forward voltage drop which rises as they heat up - I tried them once and
discovered that they are very much not a precision piece of equipment


bill n
"Stephanie Weil" <stephanienyc@gmail.com> wrote in message
news:16e71e4e-f162-452c-b9c2-bec9f34041b0@z28g2000prd.googlegroups.com...
On Jan 9, 5:54 pm, "Paul P" <REMOVE paul @ REMOVE ppinyot . REMOVEcom>
wrote:

I believe Selenium is still used in the power industry.

http://www.cehco.com/?page_id=233

Paul P.
Click to expand...
Metal rectifiers are still used in things like elevators and radio
transmission facilities, I believe. I think they're selenium.
There's also the mercury arc rectifier -- although that's not a solid
state device. :)

I've heard that copper oxide diodes were superior in that they didn't
decay with age like their selenium counterparts (as those of us
working old radio receivers know).

Stephanie Weil
KC2TJB
Holbrook, NY
 
On Jan 9, 12:23 pm, Carter <k...@ameritech.net> wrote:
On Jan 9, 8:58 am, "N_Cook" <dive...@tcp.co.uk> wrote:
Firstly are they synomynous?

Would the English military have had access to these size
and sort of ratings, of the later rectifiers, in 1940s,
they could have been heatsinked
TwoMuttHeads wrote:
Copper oxide was used for quite a while.

The "whistle" rectifier in Lionel train transformers of the 1950s were
copper oxide.
Click to expand...
Hi
Copper Oxide have the advantage for things like meters
and battery charges because they have a low forward
voltage drop. The primary problem is that it has a very low
reverse voltage. Even in charger applications, it took
a stack of many junctions to hold off the reverse voltage
of a 12volt charger.
Dwight
 
In article
<c0ab1862-4fa5-4f64-969e-bce5c1437a25@y1g2000pra.googlegroups.com>,
"dkelvey@hotmail.com" <dkelvey@hotmail.com> in
sci.electronics.repair wrote:

On Jan 9, 12:23 pm, Carter <k...@ameritech.net> wrote:
On Jan 9, 8:58 am, "N_Cook" <dive...@tcp.co.uk> wrote:
Firstly are they synomynous?

Would the English military have had access to these size
and sort of ratings, of the later rectifiers, in 1940s,
they could have been heatsinked
TwoMuttHeads wrote:
Copper oxide was used for quite a while.

The "whistle" rectifier in Lionel train transformers of the 1950s were
copper oxide.

Hi
Copper Oxide have the advantage for things like meters
and battery charges because they have a low forward
voltage drop. The primary problem is that it has a very low
reverse voltage. Even in charger applications, it took
a stack of many junctions to hold off the reverse voltage
of a 12volt charger.
Click to expand...

Their downside for meter use is low bandwidth. Fine for a 50 / 60 Hz
electrician's testmeter, useless for audio. Often way off at 400 Hz.

Regards,

David P.
 
On Jan 16, 12:23 pm, David Powell <ddotpow...@icuknet.co.uk> wrote:
In article
c0ab1862-4fa5-4f64-969e-bce5c1437...@y1g2000pra.googlegroups.com>,
"dkel...@hotmail.com" <dkel...@hotmail.com> in



sci.electronics.repair wrote:
On Jan 9, 12:23 pm, Carter <k...@ameritech.net> wrote:
On Jan 9, 8:58 am, "N_Cook" <dive...@tcp.co.uk> wrote:
Firstly are they synomynous?

Would the English military have had access to these size
and sort of ratings, of the later rectifiers, in 1940s,
they could have been heatsinked
TwoMuttHeads wrote:
Copper oxide was used for quite a while.

The "whistle" rectifier in Lionel train transformers of the 1950s were
copper oxide.

Hi
Copper Oxide have the advantage for things like meters
and battery charges because they have a low forward
voltage drop. The primary problem is that it has a very low
reverse voltage. Even in charger applications, it took
a stack of many junctions to hold off the reverse voltage
of a 12volt charger.

Their downside for meter use is low bandwidth. Fine for a 50 / 60 Hz
electrician's testmeter, useless for audio. Often way off at 400 Hz.

Regards,

David P.
Click to expand...
Yep!
Dwight
 
In article <4tq1n4ttvu5dgingtu0huh8h4sne1gc36v@4ax.com>,
David Powell <ddotpowell@icuknet.co.uk> wrote:

In article
c0ab1862-4fa5-4f64-969e-bce5c1437a25@y1g2000pra.googlegroups.com>,
"dkelvey@hotmail.com" <dkelvey@hotmail.com> in

Hi
Copper Oxide have the advantage for things like meters
and battery charges because they have a low forward
voltage drop. The primary problem is that it has a very low
reverse voltage. Even in charger applications, it took
a stack of many junctions to hold off the reverse voltage
of a 12volt charger.

Their downside for meter use is low bandwidth. Fine for a 50 / 60 Hz
electrician's testmeter, useless for audio. Often way off at 400 Hz.
Click to expand...
I thought the rectifiers used in the old VU meters, as well as various
telephony applications, were Copper Oxide? If Copper Oxide doesn't work
in audio frequency applications what sort of rectifier stacks were used
in these audio applications?

--
Regards,

John Byrns

Surf my web pages at, http://fmamradios.com/
 
In article
<byrnsj-43AB01.22052316012009@newsclstr02.news.prodigy.com>,
John Byrns <byrnsj@sbcglobal.net> in sci.electronics.repair wrote:

In article <4tq1n4ttvu5dgingtu0huh8h4sne1gc36v@4ax.com>,
David Powell <ddotpowell@icuknet.co.uk> wrote:

In article
c0ab1862-4fa5-4f64-969e-bce5c1437a25@y1g2000pra.googlegroups.com>,
"dkelvey@hotmail.com" <dkelvey@hotmail.com> in

Hi
Copper Oxide have the advantage for things like meters
and battery charges because they have a low forward
voltage drop. The primary problem is that it has a very low
reverse voltage. Even in charger applications, it took
a stack of many junctions to hold off the reverse voltage
of a 12volt charger.

Their downside for meter use is low bandwidth. Fine for a 50 / 60 Hz
electrician's testmeter, useless for audio. Often way off at 400 Hz.

I thought the rectifiers used in the old VU meters, as well as various
telephony applications, were Copper Oxide? If Copper Oxide doesn't work
in audio frequency applications what sort of rectifier stacks were used
in these audio applications?
Click to expand...

Dunno about old VU meters, but my guess is that they're rather
different to the meters and battery chargers that were the topic, in
that there will be amplification in the system. Given that, whatever
the response curve of the widget is, it can be linearized as necessary
with appropriate filters. My comment described a characteristic of
the nekkid rectifier.

It's not that they don't work at audio, just that they will only be
accurate over a very restricted frequency range. Not that I've a high
opinion on VU meters as used in typical consumer electronics, unlikely
to even equal the accuracy of my car's fuel tank contents gauge.
Might as well wire a filament lamp across the speakers and measure
with a light meter.

Regards,

David P.
 
"David Powell" <ddotpowell@icuknet.co.uk> wrote in message
news:eek:kv6n4d0k7js2am1kb2m0tmgohpebji4gn@4ax.com...
In article
byrnsj-43AB01.22052316012009@newsclstr02.news.prodigy.com>,
John Byrns <byrnsj@sbcglobal.net> in
sci.electronics.repair wrote:

In article <4tq1n4ttvu5dgingtu0huh8h4sne1gc36v@4ax.com>,
David Powell <ddotpowell@icuknet.co.uk> wrote:

In article
c0ab1862-4fa5-4f64-969e-bce5c1437a25@y1g2000pra.googlegroups.com>,
"dkelvey@hotmail.com" <dkelvey@hotmail.com> in

Hi
Copper Oxide have the advantage for things like meters
and battery charges because they have a low forward
voltage drop. The primary problem is that it has a very
low
reverse voltage. Even in charger applications, it took
a stack of many junctions to hold off the reverse
voltage
of a 12volt charger.

Their downside for meter use is low bandwidth. Fine for
a 50 / 60 Hz
electrician's testmeter, useless for audio. Often way
off at 400 Hz.

I thought the rectifiers used in the old VU meters, as
well as various
telephony applications, were Copper Oxide? If Copper
Oxide doesn't work
in audio frequency applications what sort of rectifier
stacks were used
in these audio applications?
Click to expand...
Big plates like in battery chargers = big capacitance = poor
audio response.
Very small plates like in meters = small capacitance = good
audio response.

David
 
In article <bHMcl.14543$c45.11768@nlpi065.nbdc.sbc.com>,
"David" <someone@some-where.com> wrote:

"David Powell" <ddotpowell@icuknet.co.uk> wrote in message
news:eek:kv6n4d0k7js2am1kb2m0tmgohpebji4gn@4ax.com...
In article
byrnsj-43AB01.22052316012009@newsclstr02.news.prodigy.com>,
John Byrns <byrnsj@sbcglobal.net> in
sci.electronics.repair wrote:

In article <4tq1n4ttvu5dgingtu0huh8h4sne1gc36v@4ax.com>,
David Powell <ddotpowell@icuknet.co.uk> wrote:

In article
c0ab1862-4fa5-4f64-969e-bce5c1437a25@y1g2000pra.googlegroups.com>,
"dkelvey@hotmail.com" <dkelvey@hotmail.com> in

Hi
Copper Oxide have the advantage for things like meters
and battery charges because they have a low forward
voltage drop. The primary problem is that it has a very
low
reverse voltage. Even in charger applications, it took
a stack of many junctions to hold off the reverse
voltage
of a 12volt charger.

Their downside for meter use is low bandwidth. Fine for
a 50 / 60 Hz
electrician's testmeter, useless for audio. Often way
off at 400 Hz.

I thought the rectifiers used in the old VU meters, as
well as various
telephony applications, were Copper Oxide? If Copper
Oxide doesn't work
in audio frequency applications what sort of rectifier
stacks were used
in these audio applications?

Big plates like in battery chargers = big capacitance = poor
audio response.
Very small plates like in meters = small capacitance = good
audio response.
Click to expand...
I'll buy that.

--
Regards,

John Byrns

Surf my web pages at, http://fmamradios.com/
 
John Byrns wrote:
In article <bHMcl.14543$c45.11768@nlpi065.nbdc.sbc.com>,
"David" <someone@some-where.com> wrote:

"David Powell" <ddotpowell@icuknet.co.uk> wrote in message
news:eek:kv6n4d0k7js2am1kb2m0tmgohpebji4gn@4ax.com...
In article
byrnsj-43AB01.22052316012009@newsclstr02.news.prodigy.com>,
John Byrns <byrnsj@sbcglobal.net> in
sci.electronics.repair wrote:

In article <4tq1n4ttvu5dgingtu0huh8h4sne1gc36v@4ax.com>,
David Powell <ddotpowell@icuknet.co.uk> wrote:

In article
c0ab1862-4fa5-4f64-969e-bce5c1437a25@y1g2000pra.googlegroups.com>,
"dkelvey@hotmail.com" <dkelvey@hotmail.com> in
Hi
Copper Oxide have the advantage for things like meters
and battery charges because they have a low forward
voltage drop. The primary problem is that it has a very
low
reverse voltage. Even in charger applications, it took
a stack of many junctions to hold off the reverse
voltage
of a 12volt charger.
Their downside for meter use is low bandwidth. Fine for
a 50 / 60 Hz
electrician's testmeter, useless for audio. Often way
off at 400 Hz.
I thought the rectifiers used in the old VU meters, as
well as various
telephony applications, were Copper Oxide? If Copper
Oxide doesn't work
in audio frequency applications what sort of rectifier
stacks were used
in these audio applications?
Big plates like in battery chargers = big capacitance = poor
audio response.
Very small plates like in meters = small capacitance = good
audio response.

I'll buy that.

The copper oxide meter rectifiers I have seen are about 3/16" in
Click to expand...
diameter. The one in the battery charger I have is about 2" X 4".

--
Jim Mueller wrongname@nospam.com

To get my real email address, replace wrongname with dadoheadman.
Then replace nospam with fastmail. Lastly, replace com with us.
 
On Jan 15, 6:14 pm, Stephanie Weil <stephanie...@gmail.com> wrote:
On Jan 9, 5:54 pm, "Paul P" <REMOVE paul @ REMOVE ppinyot . REMOVEcom
wrote:



I believe Selenium is still used in the power industry.

http://www.cehco.com/?page_id=233

Paul P.

Metal rectifiers are still used in things like elevators and radio
transmission facilities, I believe.  I think they're selenium.
There's also the mercury arc rectifier -- although that's not a solid
state device. :)

I've heard that copper oxide diodes were superior in that they didn't
decay with age like their selenium counterparts (as those of us
working old radio receivers know).

Stephanie Weil
KC2TJB
Holbrook, NY
Click to expand...
 
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