I use a lot of relays in various projects and always wondered what electrical life in the datasheets really meant. Given my skepticism about any claim by a Chines manufacturer I decided to see if life could really be tested.
My method is to toggle a relay 1800 times per hour while passing a constant current of 2 amps. I measured the voltage drop across the contacts 16 times for each cycle and logged everything to a 32MB flash chip.
Amazes me what can be done with an STM8 and forth.
I intend to operate the relay to failure. That may be a week or so away. But so far, after almost 6000 cycles, the results are pleasing:
The Y axis is the raw ADC result, averaged for the 6 readings. Interesting to see periods with a significant degradation in contact resistance which manifests itself as an increase in the ADC reading.
73's
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