ZHC927/M RF Switcher

1. Overview

The ZHC927/M RF switcher is a special device designed to realize automatic switching of radio/TV transmitters equipped with dual modulators (output -30dBm～+15dBm). It has automatic switching mode and manual switching mode.

In automatic switching mode, the switcher automatically detects and judges the working status of the main modulator (with or without radio frequency). When the main modulator fails and has no radio frequency output, it automatically switches to the standby modulator to work; in manual switching mode, only one key is required Complete the switch between the main and standby modulators. The working status in both automatic and manual modes has a power-off hold function.

Features:

l  With automatic and manual switching modes

l  With working status LED indication function

l  With the main and standby modulator radio frequency switch control function

l  With power failure to maintain the RF path and modulator switch status before the power failure

l  Using high-speed MCU processor control, stable and reliable performance

l  Provide remote control port

2.Technical Details

2.1 Technical Specifications:

Power supply                   AC220V/1A/50Hz

RF input and output impedance 50Ω

RF input power                 -30dBm～+15dBm

No RF switching time           2 seconds

2.2 Physical Specifications:

RF input and output connector      SMA

Communication interface            RS232

Chassis standard                    19 inches

Chassis size                         1U (440mm×44mm×300mm)

Operating environment temperature -5℃～+45℃

Relative humidity                    ＜95%

Altitude                              ＜4500m

3. System Structure

3.1 Structure and composition

As shown in Figure 3-1, the inside of the device consists of a switcher, RF detection unit, intelligent control unit, and key display unit.

Switcher: It is composed of relays to realize the radio frequency switching of the main and standby modulators.

RF detection unit: detects the radio frequency input of the main modulator, and sends the detection result to the control unit for processing.

Intelligent control unit: In the automatic mode, it judges the signal sent by the radio frequency detection unit and decides whether it is necessary to control the switch;

In manual mode, operate the switch according to the key command.

Button display unit: Button to select manual/auto working mode, and indicate the working status of the switcher through the indicator light.

3.2 Working principle diagram

Figure 3-1 ZHC927/M RF Switcher Block Diagram