black and white signal generator

例句：

1. 1. This black andwhite signal generator is used to transmit signals over the airwaves.
   这个黑白信号发生器被用来在无线电波上传输信号。
2. 2. The color TV receiver has a built-in speaker that can be turned on and off with a remote control.
   彩色电视接收器有一个内置扬声器，可以通过遥控器开关。
3. 3. The brightness-contrast signal generator is used to adjust the contrast of the image displayed on the screen.
   亮度对比信号发生器被用来调整屏幕上显示图像的对比度。