At a Glance:
- Amplifier for low frequency (LF) signals with max. output of 100 Watt
- Standard output voltage of 100 V (optionally also 50 V or 70 V)
- Short-circuit resistant
- Integrated wire breakage and short-circuit monitoring (according to equipment level 2 of the Deutsche Bahn AG)
The amplifier module V100 supplies an output of 100 W at 100 V output voltage.
Up to 17 amplifier modules (17 x 100 W) can be used in a DVS-21 system.
Application example LB line forwarding
The V100 amplifies low frequency (LF) signals of the DVS-21 system. The maxi-mum output is 100 W. Different sources can act as LF signal, e.g. call stations connected to the 4NSA (manual public address) or the speech memory module DSS1 (automatic public address).
The amplifier outlet can be switched directly to a loudspeaker circuit or to differ-ent loudspeaker circuits using the modules 4LSL or 4IOS. If a TG01 is used in addition to the 4LSL, then the individual loudspeaker circuits can be monitored for impedance deviations.
If an amplifier fails then an emergency/disaster amplifier can take over its func-tion.
The V100 is divided into function groups:
- Digital amplifier
- Disaster switch
- Wire breakage or short-circuit monitoring
The following block diagram illustrates the functionality:
Block diagram V100
A microprocessor regulates timing control between the PCM bus and the module, controls message input and output and generates the audio signal re-quired for impedance monitoring.
The codec converts the incoming digital signal into analogue LF and passes this to the opto-coupler for potential separation.
The digital amplifier amplifies the potential-separated LF signal. The operating voltage of 48 V required for this is fused.
The low-pass filter filters the amplified signal and passes it on to the output transformer.
The output signal is adjusted per default to 100 V. Optionally, an adjustment to 50 V or 70 V can be made. For this all that is needed is that a jumper be sol-dered onto the backplane of the DVS-21 system. The signal is switched over the closed circuit contact of relay 1.
In the case of a disruption, depending on the system, one or multiple amplifi-ers can be used as emergency amplifiers. One amplifier can assume the disaster function for up to 6 amplifiers. In the case of a disruption the dam-age relay (relay 2) and the output relay (relay 1) of the defective V100 drop out. The loudspeaker circuit of the failed amplifier is connected with the out-put of the disaster amplifier over the normally closed contact of relay 1. Allo-cation of the disaster amplifier is done using solder bridges on the back-plane.
Wire Breakage and Short-Circuit Monitoring
Output voltage and current in the loudspeaker line are measured for wire breakage and short-circuit monitoring. An error message is issued if pro-grammed limit values are underrun or exceeded. A TG01 and a 4LSL are required for more precise monitoring of impedance in individual loudspeaker circuits.
The Symbols on the Front Plate and their Meaning:
|The System Blinker
Addressing from processor taking place
BUS output works as push-push operation with the system blinker
BUS input works as push-pull operation with the system blinker
|On||Public Address Status Display|
|Al||Alarm Signal LED|
|(green)||Output 50/70/100 V Modulation Display|
|(red)||Output 50/70/100 V Overmodulation|
|Operating Voltage:||+/-5 V (control)|
|Operating Voltage:||48 V (power level)|
|Idle Current (48V):||ca. 70 mA|
|Operational Current (48V):||Max. 2.7 A (100 W sine)|
|Operational Current (+5V):||Max. 30 mA|
|Operational Current (-5V)||Max. 9 mA|
|Power Output:||100 W|
|Distortion Factor:||ca. 1% at maximum load|
|Output Voltage:||As required 50 V / 70 V /100 V|
|Temperature Range:||0 °C to 45 °C|
|Electrically Isolated from Output!|
|Protection Against Short Circuit and Stress Peaks!|