Monday 8 October 2018

Illuminating!

Took delivery yesterday of these working lamps.
Sold as street gas lamps on "Wish" you get 5 of them for £10 including shipping.
The only drawback is that they are LED and need a power supply of 3 Volts maximum!
All the rest of the working lights on my layout are filament bulb types wired to run off 16V ac. So, I set about making a really simple power supply to power these lamps from my 16V ac supply.
I wired 4 of the lamps in series so now needed a 12V dc supply.
I used a single diode to give half wave rectification, a small smoothing capacitor to eliminate any flicker, and a 1K ohm resistor in series with the lamps. this gave me a measured 11.5V across the lamps, Just shy of the recommended working voltage. They are seen on test in the picture. I left them running for over an hour and the series resistor never got warm The current consumption is about 10mA.
If you follow this idea and use all 5 lamps in series you can dispense with the IK ohm resistor or replace it with a low value one of say 100 ohms.
All I have to do now is paint the lamp posts chocolate and cream and install them on the platform.

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