yereverluvinuncleber on DeviantArthttps://www.deviantart.com/yereverluvinuncleber/art/1940s-Policeman-s-lamp-conversion-to-LED-bike-lamp-663769112yereverluvinuncleber

Deviation Actions

yereverluvinuncleber's avatar

1940s Policeman's lamp conversion to LED bike lamp

Published:
556 Views

Description

This is a conversion I carried out on an old 1940s British Police lamp.  It had a conventional bulb powered by an old 4.5v vertical twin battery that is no longer manufactured. So, it was open to conversion being impossible to run in a conventional way due to total obsolescence of the main component. For the donor lamp I took an LED tent lamp from ebay with 24 LEDs and dismantled it extracting the LED circuit board and the battery holder/batteries. All else was discarded.

I placed the LEDS and mounting board on top of the old reflector, setting them in place with a silicon potting compound. They mount just flush with the glass leaving a little space to dissipate any heat. The silicon is transparent and not visible. The whole face is filled with the LEDs. The old reflector is retained allowing easy mounting of the LEDs/PCB board and giving the wiring easy access to the lamp body through the old bulb hole.

It is as if the old lamp and new components were destined for each other. Inside the battery holder is free-floating being held with a dob of silicon and the batteries bound with tape to keep them in the holder. Batteries are easily changed. It runs on three 1.5 v AA batteries found everywhere.

The old lamp body had a rust hole on the right hand side where a battery had leaked causing a weak spot. I drilled out the hole and mounted an old toggle switch that had been reclaimed from some old 1930s electrical tech. That switch was mounted on the lamp using the conventional screw to tighten it to the body.  Some soldering of suitable low power, low resistance cables and the switch operates with a proper old fashioned 'clunk'.

The lamp in use? Well, it is literally a difference of night over day. When the old lamp was operated the 4.5v bulb shone with an adequate light that illuminated a human face or cast some light into a dark room. Not super bright by any means but adequate by 1940s standards. The new functionality is astounding. One click of the switch is enough to bathe the whole room in a directed narrow beam of pure light. The 24 LEDs are a massive and phenomenal upgrade that makes this old torch super-useful! The old lamp would require a change in battery fairly often, it was a large two cell battery about 3.5" tall and each an inch in diameter. The new batteries are small and due to the LEDs being low consumption, the batteries last for days.

The torch is held by a belt bracket on the rear that easily slips over a large leather belt, it also has a handle and two threaded screws that allow it to be mounted on a bracket, so it could be bike mounted too.

I feel no guilt about upgrading this lamp. I have had it for years and have contemplated an upgrade through all my onwership. It is not until now that such an upgrade is both possible and practical, the upgrade components being so cheap and readily available. No components have been thrown away, the old bulb and bulb-holder have been placed inside the lamp and secured with a blob of silicon so that if any future historian wants he can put the old lamp back again.

All this was preceded by dismantling, derusting and a respray, externally five coats using conventional car spray paint, satin black. Inside it was painted with kurust and sprayed as above.

I am very pleased with the result and I use the lamp daily. It is how all lamps should be made!

This tent lamp was the source of the materials, LEDs, battery holder &c:

www.ebay.co.uk/itm/Camping-Ten…

At only £2.95 it is a really cheap source of components for a similar conversion.
© 2017 - 2024 yereverluvinuncleber
Comments6
Join the community to add your comment. Already a deviant? Log In
Evil-Shieldmaiden's avatar
Interesting upgrade.  I'm glad it worked out so well, and is providing much needed light.