TRDS4001
13 / 18
User Manual
Rev. 5.2 - 23/06/06
5. Electrical Description
5.1 Introduction
This chapter describes the TRDS4001 ENCODER function . For utility, the device is
divided in subassemblies which will be deeply discussed in the following paragraph.
5.2 Power Supply
The power supply section is composed from a transformer (115-125-230-250 V)
which supplies the voltages of 11-0-11 V, afterwards they are reduced from the power
supply to +5, +8 and -8 V necessary to feed the cards of analogic section and digital
logic, included on the RDS encoder.
The 24V input section (now it is standard), in case of mains absence, automatically
commutes the feeding on the external battery, therefore guaranteeing the continuity
of the service.
5.3 RDS Circuit
It presents a microchecker which manages the production of RDS message. The
setted RDS message is preserved also in absence of primary power supply.
The RDS carrier wave at 57 Khz is produced on locking at the 19 Khz one of MPX
signal in input for the stereo transmission systems, or with an internal quartz oscillator
for the mono transmission systems. In the stereo systems the stereo led lights. The
into codifier microchecker could immediately modify the transmitted message; that
guarantees the system very much fexible and adattable at the different custumers
necessities.
5.4 Mono PB Filter Card (Only For TRDS4001/M)
The /M option (
Mono Input Option
), enables the Mono input (XLR connector) placed
on the rear of the encoder (chap. 4.3.2 - [3]), in conjunction with the shifting of JP8
jumper present on RDS Coder card that must be place in 2-3 position (see the figure
below). This card have the only function of filtering at 15 kHz of Mono input.
