Transport loud-speaking device TLD-0049-2

Purpose and scope

Transport loud-speaking device (TLD-0049-2) is intended for transmitting voice information from the driver or another person into the passenger compartment of the bus, trolleybus, tram.

The presence of the2-channel low frequency amplifier enables to transmit voice information to twocarriages in a coupling.

Note: TLD-0049 can be used for school buses or other transport vehicles, which require not only inner, but also outer voice information with the independent volume control through the channels.

 1. Transport loud-speaking device (low frequency amplifier unit)

 1 pc.

 2. Microphone M-0905

 1 pc.

 3. Microphone holder 

 1 pc.

 4. Operation manual

 1 pc.


Note: the delivery set includes the mating connector for the TLD.


1. Frequency range

not narrower than (300…10000) Hz 

 2. Rated supply voltage 

+(12/24) V

 3. Load resistance

Rated load resistance


4 Ω

 4. Max. output power of a sinusoidal signal at the load of 4 Ω and harmonic factor=10% at the supply voltage 12/24 Vrespectively

not less than 2 x 4/16 W

 5. Ready time for operation after connection

not more than 1 s

 6. Ready time for operation after pressing the button 

not more than 0,1 s

 7. Continuous work time of TLD

not less than 24 h

 8. Consumption current in the silent mode

Consumption current in the max. power mode at the load of 4 Ω at the supply voltage 12/24 Vrespectively

not more than 80mA

not more than 0,35/0,8 A

 9. Operating voltage range

9–32 V

 10. Operating temperature range 

(-20…+40) °C

 11. Storage temperature range 

(-30…+80) °C

 12. Dimensions of the LF amplifierunit

not more than170×70×56mm

 13. Dimensions of the microphone 

not more thanØ50×170 mm

 14. Weight of the LF amplifier unit 

not more than 0,4 kg

 15. Weight of the microphone

not more than 0,25 kg



The acoustic signal is converted into the electric signal by the microphone, is given to the microphone preamplifier and arrives at the audio power amplifier of the 2-channel LF amplifier unit.

The level of each channel is independently adjusted by the potentiometers Gr. 1 (loudspeaker 1) and Gr. 2 (loudspeaker 2), please refer to pic. 1below.

The talk mode is provided by pressing the button on the TLD microphonehousing.

TLD is universal in the supply voltage: it works both from 12 V and 24 V.

TLD has a built-in filter against the power-supply noise, protection against polarityreversal, accidental short circuitin the load circuit and getting of supply voltage to the LF amplifier output.

Structurally TLD is made in the form of the microphone and the LF amplifier unit, placed in the metal housing.


Pic. 1.  TLD-0049-2


Warranty period: 12 months.

Average lifetime: not less than 5 years.