Automatic measurement of electrical parameters of signal relays

The manufacturing process of Metal to Carbon relays used in railway signaling systems for configuring various circuits of signals / points / track circuits etc. consists of seven phases from raw material to finished goods. To ensure in-process quality, the electrical parameters are measured manually after each stage. Manual measurement process is tedious, error prone and involves lot of time, effort and manpower. Besides, it is susceptible to manipulation and may lead to inferior quality products being passed, either due to deliberation or due to malefic intentions. Due to erroneous measurement of electrical parameters, the functional reliability of relays is adversely affected. To enhance the trustworthiness of measurement of electrical parameters & to make the process faster, an automated measurement system having proprietary application software and a testing jig attachment has been developed. When the relay is fixed on the testing jig, the software scans all the relay contacts and measures all the electrical parameters viz. operating voltage / current, contact resistance, release voltage / current, coil resistance etc. The results are displayed on the computer screen and stored in a database file.