| 摘要 |
PURPOSE:To realize a pulse-width modulating amplifier of simple constitution which can generate high electric output power, by exercising alternate ON-OFF control over output switching elements synchronizing with a pulse-width modulated signal. CONSTITUTION:When pulse-width modulated PWM signal (a) is low in level, voltage +Vcc is applied only across capacitor C1 since voltage-applying switching element 9 turns ON, so that -Vcc will be developed at push-pull output terminal (d) via output switching element 5. Next, when PWM signal (a) is held at a high level, voltage-applying switching element 8 turns on to apply voltage +Vcc only across capacitor C2, and consequently terminal (b) is held at a voltage of +2Vcc to output +2Vcc to push-pull output terminal (d) via switching element 4. Therefore, a composite wave at output terminal (d) is a signal of 3Vcc in amplitude that synchronizes completely with PWM signal (a). |
