| 摘要 |
PURPOSE:To halve number of coils for boosting to number of LEDs and to save number of the coils by using one coil in common to two LED boosting means. CONSTITUTION:An LED blink signal is fed respectively from ports P2-A and P2-B of a control section to a base of transistors(TRs) 35, 34 of an LED circuit. For example, in case of blinking the LED 32 only, current flows to the TR 35 by a signal from the port P2-A to make the voltage at a point P nearly equal to the voltage at a power supply 31. If a signal comes further from the port P2-B in this state, a current flows to the TR 34 and the energy is stored in a boosting coil 40. No current flows to the TR 34, only the LED 32 only is lighted by a counter electromotive force generated in this case, and the waveform is repeated and only the LED 32 is blinked. Thus, number of boosting coils is saved. |
