At a Glance:
- Generate a test signal for impedance measurements using the 4LSL
- Earth leakage recognition in loudspeaker circuits
The test signal generator module TG01 generates a reference signal for impedance measuring in loudspeaker circuits. In terms of functionality it works together with the module 4LSL.
The TG01 also detects earth leakage in loudspeaker circuits.
The TG01 is part of an application for monitoring impedance in loudspeaker cir-cuits. It generates the reference signal necessary for the loudspeaker circuit function card 4LSL.
Application example of loudspeaker circuit monitoring
The principle functions of the TG01 are illustrated in the following block diagram
Block diagram TG01
A 125 Hz sine signal is generated on the TG01 module. This signal is isolated galvanically from the control block, amplified by a transformer, and passed over the output transformer to the measuring module 4LSL.
The 4LSL passes the reference signal over relays to the loudspeaker circuit to be measured.
More about impedance measuring is described in the 4LSL data sheet.
The reference signal can be used by multiple 4LSL modules in the system.
The earth leakage recognition on the TG01 is only active during an impedance measuring cycle. An earth leakage can be localized since impedance measuring is always done in respect to the loudspeaker circuit. When earth leakage is occurring inthe loudspeaker circuit being tested it is detected over the opto-coupler input of the TG01. Earth leakage is signalled by a red LED on the front plate of the module and passed to the 4LSL. When impedance measuring by the 4LSL is finished then the earth leakage LED on the TG01 switches off.
A requirement for monitoring earth leakage with the TG01 is an earthed +potential.
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
Test signal is being sent
Has operating voltage
|Al1||Not in Use|
Earth leakage on the tested loudspeaker circuit
|Operating Voltage:||+/-5 V (control)|
|Operating Voltage:||48 V (output amplifier)|
|Temperature Range:||0 °C to 45 °C|