NIGHTLIGHT BUILT FROM AN X-RAY TUBE

As with any vacuum tube, the Roentgen x-ray emission tube has a filament heater. In most x-ray tubes, the filament voltage is 24 VAC which heats the tube base to white heat. These large tubes can be converted into a lamp that makes an interesting conversation piece. Pictured above, is a small ‘nightlight’ version made from what is called a ‘Sealed Head Unit’ – the small basketball size x-ray machines that one sees in the office of a dentist. The High-Voltage transformer, filament transformer, and x-ray tube are all housed together in the small oil-filled box.

In this particular case, we simply removed the faceplate to which everything was attached, lifted it all out of the oil, and allowed it to drain. The HV tranny was then disconnected for other use. The inverted phenolic faceplate has the filament transformer and x-ray tube mounted on it, along with input terminal connections. The only modifications necessary are the installation of the line cord and a small quite 24-Volt computer fan underneath to cool the base of the tube. The output of the transformer is connected to the fan via a small bridge rectifier.