Surge load experiment design and results analysis of relay
Due to the transient overvoltage or overcurrent when relay's contacts switch different loads, the relay's contacts are damaged by transient arc erosion of electrical-over-stress, which influences the reliability of relay seriously. Firstly, according to the life test requirements of one type of electromagnetic relay with permanent magnets, the load circuit and the testing program are designed, which has characteristic of adjustable surge current time. Secondly, the contacts' breaking arc and closing bounce under 2A resistive load, 5A resistive load and surge load are analyzed. The influence of surge load on relay's electrical life is studied with increasing of test cycles. Finally, based on the testing data, the optimal design of relay has been modified and the results have been analyzed, which is helpful for improving the life of the relay.
Study on the Relationship Between the Operation Cycle and Make Arc Duration in the Electrical Endurance Test
The experiment was carried out to understand how the operation cycle affect the make arc duration in the electrical endurance test under the different surge current conditions.It is showed that the arcing duration is with the characteristic of randomness in each operation and does not have definite correlation with the operation cycle,and can get higher or lower or fluctuated in the test period.
Spark quenching at relay contacts interrupting d.c. circuits
Quenching by resistors and by condensers in parallel with a switch having silver contacts is discussed, and a number of experiments are described which throw light on it. Explanations for the major phenomena in terms of the known properties of arc and glow discharges are offered which appear to be consistent with the experimental facts. The data and reasoning appear to be a sufficient basis from which to decide the approximate values of components needed to effect quenching in any given conditions within the range covered by the experiments.