Telecast Adder 161, Instruction Manual

Adder™ 161

A/D, TX

High speed analog to digital converters located in each audio
 channel.

Multiplexer, TX

Sequentially presents two RS-422 digital inputs, four contact
closures and sixteen digitized audio signals from the A/D
converters to the optical output driver.

Demultiplexer, RX

Takes sequential digital signals from the pin diode and separates
them: sixteen to the D/A converters, two to the RS-422
 transmitters and four to the contact closure relays.

D/A, RX

High speed digital to analog converters located in each audio
channel convert the digitized signal back to analog audio.

Battery charger

The battery charger (shown in Figure 16) is active whenever

     (all units)

an Adder 161 unit is receiving DC power between 13.8 and
24 VDC. Charging current is limited to a trickle level at any
voltage input. Full charge takes 16 hours.

1

4

+12 VDC to +24

 VDC

Front Panel 

Power Switch

External
Power 
LED

Internal 
Reserve
LED

Front 
Panel

Charge 
Control 
Circuit

Internal
Battery

Switch
Mode 
Power

Power to 

Electronics 

Main Circuits Explained

Accessory List

The following accessories are available from Telecast:

• Optical power meter kit (includes wavelength filter)
• Cable repair kit
• Loop-back cable to localize signals during installation test
• Replacement Ni-Cad battery pack
• Quick-crimp kit to attach ST connectors to fiber optic cable
• Prefabricated cables built to custom lengths

Table 7. Adder 161 Main Circuits

Figure 16. Battery Charger Block Diagram

16