22nd Feb 2017, 3:45 pm | #141 |
Retired Dormant Member
Join Date: Apr 2014
Location: Church Stretton, Shropshire, UK.
Posts: 6
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Re: Mercury Arc Rectifier? Where to start
I've just picked up this old thread. I had charge of two at my old power station, a 13kW and a 26kW, Electric Construction Co of Wolverhampton, used for charging the 1200Ah station battery. As one was always running to balance the DC load on the battery, and they were swapped on a regular basis, and the equipment served for about thirty years, the running hours for each would have been about 120,000, although the dipper did drop off one after about 25 years. The ECC rep took it back for repair strapped in the front seat of his car, looking like a Martian.
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5th May 2017, 7:51 pm | #142 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,107
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Re: Mercury Arc Rectifier? Where to start
BUMP for this thread-
Lucien, did you do any more experimentation or make any videos of MAR operation? Where can they be accessed if so..? Thanks Dave P |
14th May 2017, 3:33 pm | #143 |
Pentode
Join Date: Apr 2017
Location: South Coast, Western Australia.
Posts: 129
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Re: Mercury Arc Rectifier? Where to start
I recall about 35 years ago there was a huge MAR (maybe two...) in the yard of a water treatment plant in Holymoorside, Derbyshire. It was packed in straw in a wooden crate and fascinated me. I was tempted to 'borrow it' as it seemed destined to be smashed or thrown away. As far as I recall it was supposed to have come from the tram or trolley bus system in Sheffield although how or why it ended up in Whispering Well Treatment Plant I don't know. Maybe it ended up at Crich Tramway Museum which is close by as spotted by a poster a few pages back.
It was truly enormous- memory fades but it must have been a couple of feet high and like a big glass octopus. BC |
14th May 2017, 3:57 pm | #144 |
Dekatron
Join Date: Nov 2009
Location: Lincolnshire, UK.
Posts: 5,000
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Re: Mercury Arc Rectifier? Where to start
A sad story, which I may have already told. I used to have a nice old mercury arc rectifier which was in its original box and mounted in a proper cradle complete with its instructional circuit diagram. I had this at home for many years until one day we were having a clear out of all the old and dangerous chemicals at work, including something like around 20 Kg of mercury. I decided that my rectifier was too dangerous to leave for my relatives to have to deal with when I eventually 'depart', so I took it into work and put it with all the containers of waste mercury to be taken to the destruction centre at Ellesmere Port - I regret doing that now.
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14th May 2017, 5:00 pm | #145 |
Octode
Join Date: Jul 2006
Location: Willand, Devon, UK.
Posts: 1,023
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Re: Mercury Arc Rectifier? Where to start
There was a huge one on ebay a few months back, good condition and about 5' tall, it was just too far for me to collect and would have to sort out a hire van as it wouldn't fit in mine with the racking in the way. I wish I'd put in the effort to get it now.
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21st May 2017, 10:27 am | #146 |
Rest in Peace
Join Date: Apr 2008
Location: London, UK.
Posts: 2,508
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Re: Mercury Arc Rectifier? Where to start
Hmm, sorry, not yet Dave. I'm just enjoying my first real day off this year and haven't seen a bulb for a month or two, let alone played with one. But this is definitely on the agenda and I will post results and info here when I have any. The aim is to develop the most compact and economical DIY ccontrol gear that will convincingly operate a bulb that has none of its original gear left. I have concentrated mainly on collecting rectifier equipments complete so this is not a situation that has arisen here much but evidently there are lots of bulbs about that have long since been separated from their installation.
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8th Jun 2017, 7:26 am | #147 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,107
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Re: Mercury Arc Rectifier? Where to start
Ok Lucien, no problem!
A large 3ph 150/3 MAR bulb has just come up on ebay, c/w a period sprung transit case. I shall not be bidding, but it may be worth following for interest- or possibly insurance- purposes. |
14th Jun 2017, 5:37 pm | #148 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,107
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Re: Mercury Arc Rectifier? Where to start
For info, said MAR tube went for £255 in the final minutes. Ironically i think it might have been held back slightly by being 3 phase..
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15th Jun 2017, 6:37 am | #149 |
Heptode
Join Date: Oct 2009
Location: Melbourne Australia
Posts: 901
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Re: Mercury Arc Rectifier? Where to start
The 1927 book by Prince and Vodges is well worth a read whilst waiting for the next MAR to come up on ebay !
https://archive.org/details/principlesofmerc00prin I had an old copy of chapter 8 in the shelves, as it presents all the basics of industrial rectified power supplies prior to phase regulation becoming achievable. |
16th Jun 2017, 8:06 pm | #150 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,107
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Re: Mercury Arc Rectifier? Where to start
Intriguing and in parts baffling!
Interesting that significant presence of red spectra indicates the atmosphere has started to leak back inside. Detection method: view rectifier through red glass. |