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Projector HID arc light mounted into a desk lamp

2012-02-12

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I combined the High Intensity Discharge bulb and power supply from an old LCD with a desk lamp to create a 270W spotlight. I bypassed the power supply's interlocks and shorted an optocoupler to cause the power supply to always turn the lamp on when AC power is applied. I used an inline power switch to control the device. The desk lamp's existing wiring is able to withstand the high starting voltage of the HID lamp (probably a few KV). Once the arc strikes, the voltage is much lower and the current much higher.