| 摘要 |
PURPOSE:To prevent malfunction of a circuit to be controlled, by providing the 1st circuit generating different output voltages at the application of a single switch and a plurality of switches, the 2nd circuit having a threshold value of state inversion between the different voltages and a switch element to be controlled. CONSTITUTION:A circuitIhas enhancement FETs E1-E4 which set depletion FETs D1-D4 as a drain load directly coupling the gate and drain and receive a negative voltage through the application of switches S1-S4 corresponding to each gate as a control input, and source resistors in common. A circuit II forms a negative feedback sensor amplifier having a threshold value of status inversion between output voltages of the circuitIand its output is sent to a switching element T to be controlled. Since one of circuits C1-C4 to be controlled is operated only when one of the switches S1-S4 is applied, malfunction of the circuits to be controlled due to misoperation of >=2 switches by the switch element T can be prevented. |
