Testing LED strip
Many people do not realise how much heat is generated by modern high brightness LEDs. An old-fashioned 100W incandescent light bulb produces around 5% visible light, 83% infrared radiation and 12% heat. An equivalently bright LED bulb might produce 30% visible light and 70% heat. Although the total power consumption is much less (around 17W for the LED), the amount of heat which must be dissipated at the source is almost the same (12% of 100W is 12W, 70% of 17W is 11.9W), and LEDs are easily damaged by excessive heat. A recent purchase of 5m of inexpensive (£2.59) white LED strip prompted an investigation of its performance, particularly the thermal properties. Excessive heat often causes rapid failure of LED strips, so this seemed likely to be a useful exercise. This investigation began with a 0.5m length of warm white 5050 SMD strip with 60 LED chips per metre. 5050 LED chips have three diodes per chip, as can be seen here: The strip was supplied as a 5m reel in a sealed bag. This is made up of 10 0.5m sections joined by solder blobs into a continuous length. Powering a 5m st