| 摘要 |
The circuit comprises an operational amplifier 2 connected to the cell 1, and a current mirror circuit 7 with at least one component in the feedback path of the amplifier 2. A further amplifier 3 provides an output signal from the circuit. The amplifiers may operate at different pedestal voltages. FET 12 shorts the output of the cell when it is not in use, and the FET is switched off gradually by charging capacitor 13 when the power supply to the cell is energised, reducing settling time of the system. Diodes 10 and 11 provide a reverse current path and prevent voltage changes which would otherwise occur if the electrode S of the cell were made positive by electrochemical reactions is the cell. The cell may be a carbon monoxide sensor. |
