Safety circuit for elevator equipment

Application Number  00129514 Application Date  2000.09.29
Publication Number  1291584 Publication Date  2001.04.18
Priority Information   1999/10/8 EP 99810919.3  
Applicant(s) Name  Inventio AG  
Inventor(s) Name  A. Lisi  
Patent Agency Code  11021 Patent Agent  jiang lilou
AbstractAn elevator safety circuit has a series chain of contacts connected between at least one safety relay, an electric power supply, a monitoring device monitoring the voltage and current in the series chain. A signal from the safety relay is transmitted to an elevator control. The voltage across the safety relay is tapped and transmitted to a network connected to a voltage converter of the power supply. If all the contacts of the series chain are closed, the voltage across the safety relay is held constant. Regulation of the voltage across the safety relay makes the safety circuit, with respect to voltage drop, independent of the length of the cabling connecting the contacts.