| 摘要 |
A first operational amplifier feeds a DC signal to first and second inverter means which are operated in opposite senses of polarity and which convert the DC output signal of the first operational amplifier to first and second stepped-up differential AC voltages at the same predetermined synchronized frequency. These stepped-up voltages are then converted to corresponding first and second DC voltages. A second operational amplifier is connected to the output of the first operational amplifier which drives a LED-photoconductor circuit to provide further system gain. |
