| 摘要 |
<p>PURPOSE:To obtain a convenient optical input switching device by connecting a photoelectric converting element between the source and gate of a normally-on FET and a normally-off FET. CONSTITUTION:The photoelectric converting element P1 and a normally-on FET3 are connected between the source and gate of the normally-off FETT1 and the normally-on FETT2. A photoelectric conversion element P2 and a discharge resistor R1 are connected between the source and gate of the FETT3. When an input signal enters and a light emitting element L1 is lighted, the photoelectric conversion elements P1, P2 produce an electromotive force to turn on the FETT1 and to turn off the FETT2. When the input is lost and the photoelectromotive force is lost, the FETT1 is restored to off-state and the FETT2 is to on-state. In this case, the FETT3 is restored to ON to discharge the residual electric charge of the photoelectric conversion element P1, then the operation is quickened. Further, the FETd T1, T2 are used as normally on/off contacts of a contact relay to offer convenience.</p> |
