| 摘要 |
PURPOSE:To start a series control type voltage stabilizer without saturating a control transistor, by using a specific circuit including a photocoupler and a Zener diode. CONSTITUTION:A transistor TR of a photocoupler 34 is connected to a Zener diode ZD37 as shown in the diagram, and a series control type voltage stabilizer is started by a command control signal which is applied through an input terminal of the coupler 34. For instance, the collector current of the TR of the coupler 34 flow when a pulse-like command control signal is supplied to terminals 38 and 39. This current is used for the base current of a control TR23, and the TR23 moves to an active region. Thus the voltage is delivered between terminals 32 and 33. When this voltage gives the conductive to the ZD37, the potential increases for the emitter of the TR of the coupler 34. Accordingly the base of the TR of the coupler 34 is advesely biased with the rise of the series control type voltage stabilizer if the Zener voltage is selected to a proper level. Thus no collector current flows. |
