several methods protection LED power supply circuit described

1 through protection circuit

Half-and full-bridge is commonly used in switching power supply topology, "through " its a great threat, through two transistors of the same leg while at the same time, the phenomenon of conduction. In the commutation period, switching power supply vulnerable to interruptions caused by direct, excessive current may damage through the power electronic devices for inverter. Once through the phenomenon to be detected as soon as possible and immediately driven off to avoid the accumulation of switching device is too large PN junction and burn calories. Here a double flip-flop CD4528 monostable integrated design of a full bridge and half-bridge for the direct detection, protection circuits.

CD4528 with two one-shot, the truth table shown in Figure 1. Chip 3 feet and 13 feet respectively, within their one-shot circuit two separate Clear-side, 5 feet and 11 feet to the B input of the monostable, 4 feet and 12 feet for the single steady state of the A input. B termination high, only when the Clear side is high, A-side edge trigger input to be effective.