| 摘要 |
<p>The fence has a supply battery, an h.v. pulse generator between the battery and the fence, and a battery testing circuit in parallel with the battery. The circuit has a display device and a switch for its connection to the battery. The battery testing circuit has a threshold circuit (T1, ZD1) to whose input, when the switch (S1) is closed, a voltage proportional to the battery voltage is applied. A relay (K1) is connected to its output. When the relay is not energised, its contact (1) is connected to one display element (LED2), and when it is energised, the contact (1) is connected to a second display element (LED1). The display element connected to the contact when the switch is closed, is connected to at least a part of the battery voltage. The threshold circuit threshold is such, that when the switch is closed, the relay is energised only when the battery voltage is sufficient to ensure the fence correct operation.</p> |
