本例中的电路使用一个简单的比较器电路做上电时间的延迟,用于汽车倒车摄像头。汽车制造商通常会用倒车灯电路为倒车观察摄像头供电。在自动档汽车中,当从驻车转到行车状态(或相反)时,档位切换要经过倒车档,此时摄像头会加上一个短暂的电源脉冲。这种突发的电压脉冲不利于摄像头中的灵敏电路,可能缩短其寿命。本例提出了一种避免这种情况的简单而廉价的方法。本电路的输入端连接到倒车灯的正极和负极端子(图1)。电路通过一只MOSFET为摄像头供电。R1与C1构成一个时间延迟元件(参考文献1)。当倒车灯亮时,它通过电阻R1为电容 The circuit in this example uses a simple comparator circuit to delay the power-on time for a car reversing camera. Car manufacturers often use the reversing light circuit to power the reversing camera. In automatic vehicles, when switching from Park to Drive (or vice versa), the gear shifts past the reverse gear and the camera adds a brief power pulse. This sudden voltage pulse is not conducive to the sensitive circuit in the camera, may shorten its life. This example presents a simple and inexpensive way to avoid this situation. The input of this circuit is connected to the positive and negative terminals of the backup lamp (Figure 1). The circuit powers the camera through a MOSFET. R1 and C1 constitute a time delay element (Reference 1). When the reversing light is on, it passes capacitor R1