| 摘要 |
<p>The proximity switch consists of an oscillator driving a flip-flop and driving an output stage that switches the load. The state of the switch is indicated optically. The switch has two possible states: switching circuit under voltage or switching circuit on. These two states are indicated by a single shared LED device (4, 5) which emits light of different colours. The dual-colour LED device is driven from a complementary-transistor push-pull stage (T2, T3) itself driven by the flip-flop or by the oscillator. The LED device is connected at its output via a voltage divider (R4, R5, D1, R6) to the output stage (T4, T5).</p> |
