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Other Vintage Household Electrical or Electromechanical Items For discussions about other vintage (over 25 years old) electrical and electromechanical household items. See the sticky thread for details. |
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12th Oct 2020, 6:43 am | #21 | |
Nonode
Join Date: Jan 2010
Location: North Somerset, UK.
Posts: 2,129
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Re: Lamp for elderly anglepoise light
Quote:
Alternatively connect the lamp to a Variac or similar and observe the input current at different voltages. At 220 volts, the mains input current will be greater than at 250 volts, indicating the presence of a regulating circuit. A simple capacitive dropper would draw less current at a reduced line voltage, and produce less light. Also, many types of these lamps are rated for operation from 50 cycle or 60 cycle mains, a simple capacitive dropper would draw significantly more current at the higher frequency. |
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12th Oct 2020, 8:23 am | #22 |
Hexode
Join Date: Oct 2010
Location: Box End, Beds. UK.
Posts: 271
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Re: Lamp for elderly anglepoise light
Well the only sign of a circuit board is entirely within the bayonet cap, and it has a hole in the middle where the seal of the bulb passes through it, so if there are SM components on it they are only small ones; there are no signs of parts on the side I can see. Also the bulb appears to be at least partially evaluated. Why would an LED require the bulb to be evacuated and/or a special filling gas. All most puzzling.
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12th Oct 2020, 9:47 am | #23 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,820
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Re: Lamp for elderly anglepoise light
Let's have a photo, then.
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12th Oct 2020, 10:33 am | #24 |
Hexode
Join Date: Oct 2010
Location: Box End, Beds. UK.
Posts: 271
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Re: Lamp for elderly anglepoise light
I will try to get a photograph, but looking again there is a four pin device, I suspect a SM bridge rectifier visible and a tiny 2 terminal device, probably a resistor
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12th Oct 2020, 11:29 am | #25 |
Hexode
Join Date: Oct 2010
Location: Box End, Beds. UK.
Posts: 271
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Re: Lamp for elderly anglepoise light
Photographs
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12th Oct 2020, 2:18 pm | #26 |
Nonode
Join Date: Jan 2010
Location: North Somerset, UK.
Posts: 2,129
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Re: Lamp for elderly anglepoise light
I see no merit in the bulb being evacuated, a filling of gas or air would help in transferring heat by convection.
A sealed bulb even containing air would be preferable as the entry of dust, insects and water vapour would be prevented. |
12th Oct 2020, 7:05 pm | #27 | |
Hexode
Join Date: Jun 2018
Location: Buckinghamshire, UK.
Posts: 382
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Re: Lamp for elderly anglepoise light
An interesting article:-
https://www.ledinside.com/knowledge/...filament_bulbs Quote:
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14th Oct 2020, 7:38 pm | #28 |
Hexode
Join Date: Oct 2010
Location: Box End, Beds. UK.
Posts: 271
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Re: Lamp for elderly anglepoise light
Having found a suitable lamp and being puzzled as to how it works I thought I might see what the current waveform is like. Somewhat horrified at what I found I tried a "normal" LED lamp, and two CFLs. All of them are horrible (hover over the pictures and the file names should tell you which is which).
The electricity supply companies must hate these things |