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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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8th Mar 2023, 12:42 pm | #1 |
Dekatron
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Philips Bakelite BC-to-ES switched adaptor
A friend has just passed this on to me. She’s 80 and it was owned by her parents, so it could date from anywhere between the 1930s and the 1960s. I’ve not seen one like it before. The switch mechanism is unusual as the knob only turns clockwise, switching on and off sequentially.
The Philips part number is “z9901” but an internet search has so far turned up nothing. Phil
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8th Mar 2023, 12:51 pm | #2 |
Dekatron
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Re: Philips Bakelite BC-to-ES switched adaptor
I've never seen one either. ES bulbs were rare over here until relatively recently, especially for normal domestic lighting applications. I wonder whether they had some specific use in mind, e.g. for a photographic or infrared heat lamp, both of which were made by Philips.
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8th Mar 2023, 12:52 pm | #3 |
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Re: Philips Bakelite BC-to-ES switched adaptor
I wonder what the intended use was? There were plenty of switched BC splitters so that people could run their electric blankets or sewing machines from the light socket, but I can't think of a purpose for a switched BC-ES adaptor.
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8th Mar 2023, 1:14 pm | #4 |
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Re: Philips Bakelite BC-to-ES switched adaptor
The ES socket seems to have a shade-retaining ring, so presumably use in a light fitting was envisaged. But a lighting circuit or table lamp would normally have its own switch, making a switched adaptor unnecessary.
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8th Mar 2023, 1:30 pm | #5 |
Octode
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Re: Philips Bakelite BC-to-ES switched adaptor
Nick may have something there, Photoflood lamps used to simulate daylight for indoor photography are usually ES. Originally this was achieved by using a 115V bulb. Very bright light at the expense of a short life so a switched adapter would be useful. Professionals would use a series/parallel switched arrangement to prolong lamp life. In series for setting up the shot and then to parallel and quickly taking the photo.I
Peter |
8th Mar 2023, 1:59 pm | #6 |
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Re: Philips Bakelite BC-to-ES switched adaptor
Thanks for the quick replies and suggestions. The donor said it had been used in a home-made standard lamp by her father, presumably more for the switch function than the ES socket. Oddly enough, the ‘shade ring’ does not appear to unscrew, although I have not yet taken pliers to it…!
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8th Mar 2023, 6:24 pm | #7 |
Heptode
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Re: Philips Bakelite BC-to-ES switched adaptor
Maybe purchased by someone from the USA who wanted to feel at home and not spend all their time looking for a switch on a lamp that did not exist when they came here.
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8th Mar 2023, 8:28 pm | #8 | |
Nonode
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Re: Philips Bakelite BC-to-ES switched adaptor
Quote:
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8th Mar 2023, 9:07 pm | #9 | |
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Re: Philips Bakelite BC-to-ES switched adaptor
Quote:
Fun trivia: the small push buttons that are usually built into fixtures, also turn only one way internally... |
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8th Mar 2023, 10:02 pm | #10 |
Nonode
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Re: Philips Bakelite BC-to-ES switched adaptor
How much noise does the switch make when operated?
Push-button pendants can be noisy and possibly unsuitable for bedrooms. |
9th Mar 2023, 12:12 am | #11 |
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Re: Philips Bakelite BC-to-ES switched adaptor
Hmm… on my noise meter app, it clicks at around 55dBA, much the same as a conventional switch built into a lampholder at the same distance. So I don’t think low noise is a particular feature. And yes, the shade ring does unscrew, as Duncan predicted. It just needed a little persuasion!
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9th Mar 2023, 12:39 am | #12 | |
Heptode
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Re: Philips Bakelite BC-to-ES switched adaptor
Quote:
Here's an example of a Philips dual-filament bulb (50+100w) on sale in Canada. Incandescent bulbs have not been banned there! https://www.homehardware.ca/en/50100...bulb/p/3654593 I wonder if this adaptor was designed to use a dual-filament bulb in a standard lampholder? Another possibility is that it was designed for export. BC bulbs were very much the standard in the UK; ES bulbs are standard in continental Europe. British mains sockets usually have switches, this is rare in other countries. This adaptor would be particularly useful for anyone taking a British table lamp to the continent. Then they could easily buy ES bulbs locally, the switch could be useful too. |
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9th Mar 2023, 7:00 am | #13 |
Nonode
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Re: Philips Bakelite BC-to-ES switched adaptor
My first thought was that this was intended for a twin filament bulb so as to give three lighting levels. Often called "3 way bulbs"
These were briefly popular in the 1960s but were rendered largely obsolete by affordable semiconductor lamp dimmers. 3 way bulbs were also suitable for DC mains, unlike semiconductor dimmers. Common wattages in the UK were 40/60/100 watts and 60/100/160 watts. A 3 way bulb on only the 40 watt setting was more efficient than was a 100 watt bulb dimmed to give a similar light level. 3 way bulbs for 230/240 volt circuits are no longer available AFAIK, similar lamps for 120 volt circuits are still popular in both the original incandescent format and in low energy alternatives. |
9th Mar 2023, 1:29 pm | #14 |
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Re: Philips Bakelite BC-to-ES switched adaptor
Hamid and Broadgage are correct! As can be seen from the photo below, there is a second contact to the side of the central one, visible at the top of the ES socket as shown. I had originally thought this was just a ‘stop’ to prevent the bulb being screwed in too hard. Checking with an ohmmeter reveals that the single pole switch has four positions, each reached by a quarter-turn of the operating knob, as follows:
1 - outer contact ‘on’ 2 - inner contact ‘on’ 3 - both contacts ‘on’ 4 - both contacts ‘off’ So with a standard bulb inserted, the rotary switch requires two ‘clicks’ between ‘on’ and ‘off’ states. I am very grateful for the information. Mystery solved, and I have learned some more about vintage electrical history. All I need to find now is a dual-filament bulb! Thanks all, Phil
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Phil Optimist [n]: One who is not in possession of the full facts Last edited by Phil G4SPZ; 9th Mar 2023 at 1:31 pm. Reason: Update |
9th Mar 2023, 1:36 pm | #15 |
Dekatron
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Re: Philips Bakelite BC-to-ES switched adaptor
Wow, amazing work, chaps!
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9th Mar 2023, 2:14 pm | #16 |
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Re: Philips Bakelite BC-to-ES switched adaptor
Yes indeed! The socket appears to be known in the US as an “E26d” or three-way socket. Some three-way 120 volt bulbs are available over the pond. The US standard ES thread is nominally 26mm in diameter, whereas Europe standardised in 27mm. An E27 bulb does fit into this adaptor.
Photo found on the internet. Phil
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9th Mar 2023, 2:32 pm | #17 |
Dekatron
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Re: Philips Bakelite BC-to-ES switched adaptor
The thread of the European ES screw used to, and possibly still does, have one more turn than the US version. In the GEC catalogue of 1911, lamps could be supplied with either type of ES base.
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9th Mar 2023, 2:39 pm | #18 |
Nonode
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Re: Philips Bakelite BC-to-ES switched adaptor
3 WAY bulbs for 120 volts are readily available on line from USA sellers.
They can be used from UK 240 volt supplies either via a transformer, or from a dimmer that is permanently set to supply 120 volts equivalent. Do not use a dimmer with the adjustment accessible or sooner or later the lamp will be destroyed by turning it to full on. I doubt that you will find a 240 volt 3 way bulb, and even if you do find one, it seems a pity to use it up by regular use. |
9th Mar 2023, 3:42 pm | #19 |
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Re: Philips Bakelite BC-to-ES switched adaptor
Fascinating! I have never come across the dual-filament bulbs described here!
You learn something new every day.
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9th Mar 2023, 4:52 pm | #20 |
Nonode
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Re: Philips Bakelite BC-to-ES switched adaptor
Higher wattage 3 way lamps existed, including 100/150/250 watts, these have a 3 contact GES cap.
Twin filament bulbs were used in France for street lighting. Larger filament from dusk until midnight and the smaller one from midnight until 6 AM, then the larger filament from 06-00 until dawn. Saved energy whilst still giving a uniform light at quiet times of night. Better than turning out alternate lamps after midnight as done in the UK. Twin filament bulbs are still used today for specialist applications. navigation lamps for small craft, contain two similar filaments. Usually 10.3 volts for use on 12 volt circuits with a series pilot lamp. Railway signals, with automatic switching of reserve filament when the main one fails. Hospital operating theatre lamps, often with a mains voltage 150 watt filament and a 12 volt 100 watt filament, this being automatically brought into use, from accumulators, if the mains failed. Lighthouse lamps were made with twin filaments, duty and standby, but the modern tendency was to use single filament lamps with an automatic lamp changer. TV studios used twin filament lamps, often of 5 Kw or more on each filament to vary the light level. Dimming was avoided as this altered the colour of the light. And of course motor vehicles use twin filament bulbs, for main bean headlights and dipped beam, and for combined stop and tail lights. Heavy duty handlamps were made that used a six cell NiFe battery of 7.2 volts nominal and a 6 volt twin filament bulb, 3 watts for long battery run time, and 18 watts for a bright light. |