Automatic door openers provide convenient access into and out of buildings or from one room to another, assisting those who use mobility devices, who have full hands or who want to limit their exposure to germs. Many businesses choose to install automatic door openers to improve the lives of customers and employees alike, whether they are people with or without disabilities. These electronic devices often see a high level of use, which means that reliability and energy efficiency in the components used to implement them can be crucial. KB Electronics recently worked with a customer to help provide just this type of dependable automatic door opener solution to meet their needs.
Application: The customer requested a simplified, low-cost variable frequency drive for an automatic door opener.
Overview: An automatic door opener for public building access requires various stages of operation. When the user pushes the button, the door must open, stay open for a predetermined time and then close. Operation must also take into consideration all human, mechanical or nature made obstacles, such as wind and snow.
Application Benefit: By integrating all the above-described actions, the operation will be improved, external hardware minimized and costs lowered.
Customer's Product: A pneumatic door closer for public access in and out of buildings.
Customer's Present Solution: The customer's product combines a manual door opener with a mechanical pneumatic door closer. The customer's request was to integrate the mechanical sequencing action into a variable frequency drive (VFD). KB installed the customer's door opener in the KB lab and extensively tested the door motion while measuring the motor parameters during operation. The KBVF software was customized to duplicate the desired sequencing.
KB's Capabilities for Solving the Problem: The KBVF Adjustable Frequency Drive (AFD) series incorporates a powerful micro-controller that is programmable for custom OEM applications using software that has proprietary motor monitoring capabilities. KB's engineering staff has a reputation of working directly with customer applications to reach satisfactory solutions.
KB Solution: The objective was to integrate all the control logic into the variable frequency drive software, thereby eliminating excessive hardware such as a mini PLC, 2 DPDT relays, 2 limit switches and extensive wire harnesses. The software was designed to unlatch the door lock after a programmed delay once the OPEN button was pushed, and to open and hold the door open for a preprogrammed time. After the specified time, the VFD released the opening mechanism, allowing the pneumatic closer to close the door. If the door encountered an obstacle while closing, the KBVF software would sense an increase in torque and reverse the direction of the door. Setting up right or left door opening conditions also required accurate torque measurements in both directions.
Results: Using the modified KBVF-21D with SIVFR, the customer has a low-cost, semi automatic door motion product with all the mechanical control functions integrated into the KBVF's customized software.
Customer’s Strategic Advantage: The customer got exactly what was requested with improved reliability, a space-saving design and reduced installation costs in their automatic door opener; all of which can help provide a major advantage over competitors. A win-win solution for both the customer and KB.