Modified temperature rise estimation method for switching transistors in electronic ballasts

The self-resonance half bridge and push-pull are two of the most commonly utilized circuit topologies for electronic ballasts. In these applications, transistors are used as a switch and generate some power loss. This causes the temperature to rise on transistors. In this paper, a modified temperature rise calculation technique on TO 220 type transistors is introduced in steady state analysis for more accurate estimation, thus eliminating time-intensive testing. To verify the technique, two different electronic ballasts were tested. The results of this paper show that the actual temperature measurements were approximately the same as those calculated using the modified technique.