| 摘要 |
<p>A switch circuit (10) controls the supply of electrical power from an electrical power source (11) to a load (R5). The switch circuit (10) includes a first transistor (Q1), the emitter of the first transistor (Q1) is adapted to be coupled to the power supply (11) and the collector is adapted to be coupled to the load (R5). An electronic switching device (Q2, Q3) includes an input, an output adapted to be coupled to the other side of the load (R5) and the power source (11), and an activating input. A first resistance device (R1) is coupled between the base of the first transistor (Q1) and the input of the electronic switching device (Q2. Q3). A momentary switch (S1) has first and second terminals (13, 14) and the activating input of the electronic switching device (Q2, Q3) is coupled to the first terminal (14) of the momentary switch. A pulse generation device (C1, R4) is coupled between the collector of the first transistor (Q1) and the second terminal (13) of the momentary switch (S1). A charge storing device (C2) is coupled between the collector of the first transistor (Q1) and the output of the electronic switching device (Q2, Q3).</p> |
