| Manufacturer: | Thorn EMI Lighting Limited |
| Model: | Low Voltage Display Lamp 12v 50w |
| Application: | Display Lighting |
| Wattage: | 50W |
| Diameter (max): | 65mm |
| Length: | 85mm |
| Tube Length: | N/A |
| Bulb/Tube material: | Clear glass, smooth aluminised reflector |
| Colour Temperature: | Approx 3000K |
| Peak output wavelength: | Broadband Emission |
| Total light output: | Unknown |
| Rated lifetime: | Unknown |
| Cap: | E27 |
| Operating voltage: | 12V |
| Operating current: | 4.17A (Calculated) |
| Warmup/restrike time: | None |
| Cost (original): | Unknown |
| Value (now): | Unknown |
| Place of manufacture: | Great Britain |
| Date of manufacture: | Unknown - Code B4M Present on cap |
| Lamp Status: | Working |
At first glance, not a particularly unusual lamp. Until you look a bit closer anyway. Instead of a long mains voltage C shaped filament, there's a tightly coiled 12V filament mounted above a small heat reflective disc.
The downside of the filament being mounted in this way is that combined with the smooth mirror-like reflector, is a very blotchy beam pattern compared to what it would be possible to create using an axial filament.
Also of interest in this lamp is the method that the filament is actually fastened to the support posts, in that rather than the usual crimp arrangement, the filament has actually been welded to the posts, as is the metal disc, being connected to one of the electrical connections to the filament. This must have been quite an expensive and time consuming assembly to put together compared to more conventional lamp structures.
Another point which makes me think this must be one of Thorn's slightly more upmarket lamps is the highly elaborate cardboard cradle which the lamp is packed in within its carton.
Thorn 12V 50W Low Voltage Display Lamp - General overview
Thorn 12V 50W Low Voltage Display Lamp - Beam profile from a distance of approximately two meters
Thorn 12V 50W Low Voltage Display Lamp - Showing rear of reflector and lamp cap
Thorn 12V 50W Low Voltage Display Lamp - Close-up of filament and heat reflective disc in lamp neck
Thorn 12V 50W Low Voltage Display Lamp illuminating a wall in my room from approximately two metres
Thorn 12V 50W Low Voltage Display Lamp shown while alight
Thorn 12V 50W Low Voltage Display Lamp Packaging
Thorn 12V 50W Low Voltage Display Lamp - Detail of reflector
Thorn 12V 50W Low Voltage Display Lamp - held in hand to show relative scale
Thorn 12V 50W Low Voltage Display Lamp - Showing size of lamp
Thorn 12V 50W Low Voltage Display Lamp Output Spectra
This lamp added to the Virtual Display Shelf on the 25th September 2007 at 21:34.
References: None.
Acknowledgements: Many thanks to the website reader who donated this lamp (amongst many, many others) for display.
This page last updated:
18th June 2023: Changes to page formatting to improve readability on mobile devices and some background code changes to improve search engine behaviour.
