Talk:Metal rectifier

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Specs and v/i graphs would be nice. Metal recs do behave differently to silicon. Tabby (talk) 04:14, 5 March 2008 (UTC)

And also on details of the working is necessary. —Preceding unsigned comment added by 117.211.86.74 (talk) 11:15, 19 April 2011 (UTC)

Distinction from Schottky diodes
I'm told that these are distinct from Schottky diodes but it's not apparent why that might be...

It would be good to have a remark on the physical mechanism at play. --Nanite (talk) 18:22, 9 June 2013 (UTC)


 * It's not that they're particularly different from Schottky diodes, it's that the common-or-garden silicon diode isn't a Schottky diode. Your addition "A semiconductor rectifier using a modern semiconductor (e.g., silicon instead of selenium) is called a Schottky diode." is incorrect. It remains incorrect, even though metal rectifiers can be said to be Schottky diodes (although I've never heard them called such) and the modern replacement for a large metal rectifier is often a Schottky diode.
 * Modern Schottky diodes have a lower forward voltage drop than a conventional silicon diode, which gives two advantages:
 * There is less voltage drop in the system. This matters in low voltage systems; most commonly in 12V vehicles or trailers with twin battery systems, although PV battery charger systems are probably running that a close second these days.
 * Less voltage across the diode means, for a given current, less heat generated in the diode, less heatsinking required and better reliability.
 * In comparison, mere facts such as "less wasted power" are pretty secondary.
 * To repair an old domestic car battery charger (a common place for metal rectifiers), a dead metal rectifier can be replaced by a couple of silicon diodes the size of a pencil stub and costing coppers. To replace a charger charging milk floats, a Schottky diode might well be used instead.
 * On the whole, I see no value (and a large risk of confusion) in introducing Schottky diodes so early on in this article. Andy Dingley (talk) 18:52, 9 June 2013 (UTC)


 * Aha, oops, I definitely misworded that. By the way, looking around I found an interesting video about selenium rectifiers. It looks like they do behave a lot like Schottky diodes in forward bias but they leak quite a bit on reverse... probably due to their polycrystalline nature or dirty construction that gives an inhomogeneous Schottky barrier. Interestingly, they show hysteresis on reverse bias, though I wonder if it is a high frequency transient effect since the curve tracer is tracing so fast. --Nanite (talk) 21:24, 9 June 2013 (UTC)

Beware when replacing a metal rectifier with silicon, the forward resistance is often needed and bad things can happen without it. Tabby (talk) 11:53, 29 August 2013 (UTC)

Can anyone write more about the construction properties and time of use of the copper oxide rectifier?
The selenium rectifier is covered by a separate article but there is precious little about the copper oxide rectifier. (I think it's the copper(I)oxide that was used).150.227.15.253 (talk) 11:48, 18 March 2020 (UTC)

Copper-oxide rectifier
At some point down the road, we might want to consider overhaul/split/merge "Metal rectifier" and "Selenium rectifier" articles. Maybe split this article into a new "Copper-oxide rectifier" article, or maybe merge this article with "Selenium rectifier" article? • Sbmeirow  •  Talk  • 04:15, 17 December 2020 (UTC)

metal?
Since both selenium and copper oxide are semiconductors, why is the article called metal rectifiers? Gah4 (talk) 20:38, 25 October 2021 (UTC)


 * I think because these devices are created out of a sandwich of metal layers and semiconductor layers. For selenium rectifiers, the base metal layer plate is typically aluminum (aka metal).  See drawings in books at Selenium_rectifier.  •  Sbmeirow  •  Talk  • 21:39, 25 October 2021 (UTC)