1. Product Application

KTK18(D) Mine‑used Intrinsically Safe Loud‑speaking Telephone is a mine‑used intrinsically‑safe electrical apparatus. It is installed along the roadway working face of belt conveyors, and is capable of simplex communication, signal‑knock warning, interlock shutdown and interlock light indication.

2. Main Technical Parameters

2.1 External Power Supply

External power supply voltage: DC 18V. 

a) Rated operating voltage: 18VDC. 

b) Operating current: ≤50 mA.

2.2 Internal Power Supply

Battery model and specification: Ni‑MH AAA, 0.8 Ah, 1.2 V, 8 cells in series; 

Charging current: ≤100 mA; 

Charging voltage range: ≤12 V.

2.3 Loud‑speaking Audio Signal Parameters

Communication mode: Simplex loud‑speaking communication; 

AB‑line audio signal turn‑on level: ≤650 mV; 

Loud‑speaker sound level: ≥90 dB; 

Audio distortion of loud‑speaking: ≤15%; 

Frequency response: within ±6 dB (350～3000 Hz).

2.4 Knocking Call Signal

Frequency of knocking call signal: 1.6 kHz±0.4 kHz; 

Sound level of knocking call signal: ≥90 dB.

2.5 Interlock Signal

Interlock signal mode: Red indicator lamp keeps steady‑on under interlock state; 

Interlock output control signal: Passive switch contact signal; 

On‑state resistance: ≤10 Ω; 

Open‑circuit resistance: ≥1 MΩ.

3. Basic Functions

Loud‑speaking Communication Function: The loud‑speaking telephone can perform knocking signal and simplex loud‑speaking call communication with online devices of the same model. A single‑tone alert signal will be generated when sending knocking signals.

Interlock Control Function: When the interlock button is pressed, relay contact control signal is output, accompanied by red optical signal (LED steady‑on). Communication can be resumed only after interlock reset.