DIY: Rewiring 1930s British Searchlight

Old 11-12-16, 09:56 PM
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DIY: Rewiring 1930s British Searchlight

I got this 1930s era British searchlight, and I can't for the life of me get it wired properly. This uses a 12V 25 Watt bulb. The thing is is that when I plug it in the bulb kinda explodes. I've come to the realization that it's probably due to too much power going to the socket/bulb, although I'm not sure as I have zero electrical experience. Is there anyway to make this type of bulb work as it did back then?

Thank you very much!
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Old 11-12-16, 10:39 PM
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it's probably due to too much power going to the socket/bulb
The bulb will draw on the power (amps/watts) it needs regardless of available power (assuming available power is at least equal to the watts required). If it blows it is because the voltage is too great. If the bulb is 12 volts it should be connected to 12 volts either a 12 volt battery (example: car battery) or a 12 volt power supply either AC or DC. Is that what you are connecting it to.
Old 11-13-16, 04:48 AM
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Yea, if you are feeding a 12 volt DC bulb with 120 volt AC then it's gonna blow. You will need a power supply to feed the fixture the correct voltage or you can convert it to use a 120 volt light but that may require new wiring, switch and lamp base. I assume the light was originally mounted on a truck or boat so it probably was powered by the vehicle's 12 volt DC electrical system so leaving it DC would be more original.
Old 11-13-16, 05:54 AM
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If on a 30's car. truck could have been 6 volt.
Old 11-13-16, 07:09 PM
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Thank you very much everyone for taking the time to help. I got lucky and found a 12v transformer and wired it up and it works! The first time I plugged it in I was disappointment that it didn't work, although it turns out that the 25 watt bulb really isn't bright, and that it was on. I'm just happy that it turns on.

Thank you very much for the advice. I'm not a handy guy but always find myself rewiring or refinishing something.. I'll make sure to follow this forum and hopefully will pick up some new trick.

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Old 11-13-16, 07:48 PM
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That little wall wart may not be able to supply enough current for that bulb and that may be why it isn't so bright (although 25 watts is not a lot). 25 watt bulb will draw upwards of 2 amps at 12 volts so see if your wall wart is rated for that. Should be printed on the label.

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