LDB-2 bubble voltage detector

The LDB-2 has been developed for the detection of bubble voltage or line in use on analog lines. These may be internal device ports or trunks. 

At the time of bubble voltage detection will switch with two relays to the rhythm of the ring and offer potential free make and break contacts for controlling external equipment such as flashlights. By means of a potentiometer, the time between the rings can be filled in order to generate a long contact plus 6 seconds after the last signal. In the case of "line in use" detection will change the relay state during the entire conversation. 
Both functions can be used separately or together. 

Technical information 
- Weight: 56 grams 
- Dimensions (LxWxH): 7.5 x 5.5 x 2.5 cm 
- Power supply: 230 / 12Vdc 500mA adapter (included) 
- Connection: 10-fold screw strip 
- Output: 12Vdc (300mA maximum) 

application 
For controlling external audible and visual signaling devices in noisy environments where phone often not heard.