| 摘要 |
PURPOSE: A level meter for an interactive test is provided, which systematically manages upward and downward signal levels to optimize transmission of images and data. CONSTITUTION: A level meter used for an interactive test includes an RF signal measurement unit, an upward signal transmitter, a battery voltage control and monitoring unit, and a monitor. The RF signal measurement unit is constructed of an RF inputting part(1), a tuner(2), a 1/2 IF processor(3,4), a level sensor and data modulator(5) and a micro-controller(6). The upward signal transmitter includes an upward transmitting amplifier(7), an upward modulator(8), an upward signal generator(9) and an upward data controller(10). The battery voltage control and monitoring unit has a broadcasting network line voltage detector(11), a battery(12), a battery charging part and input part(13), a battery level detector(14), a voltage booster(15) and a power generator(16). The monitor is constructed of a display(17), a key input part(18) and a printer. An RF signal measured by the RF signal measurement unit passes through the tuner and the 1/2 IF processor to be processed by the level sensor and data modulator to be applied to the micro-controller. |
