| 摘要 |
<p>A light-triggered switching circuit which comprises a PNPN element (1), a resistor (9), and control means (11a). The PNPN element (1) is made of a P-type emitter layer (2), an N-type base layer (3), a P-type base layer (4), and an N-type emitter layer (5). The resistor (9) is connected between the P-type base layer (4) and the N-type emitter layer (5). The control means (11a) is connected between the P-type emitter layer (2) and the N-type emitter layer (5). It controls the PNPN element such that the PNPN element performs a switching operation only when a voltage applied between the P-type emitter layer (2) and the N-type emitter layer (5) is lower than a predetermined value while a first amount of light is being applied to the PNPN element, and is also performs a switching operation, regardless of the value of the voltage applied between the P-type emitter layer (2) and the N-type emitter layer (5), while a second amount of light, different from the first amount of light, is being applied to the PNPN element.</p> |
