Hi guys,
my customer ask me to realize one digital input (the pin source the voltage to make reading) with large hysteresis and some 18V pulse for contact cleaning.
For make digital input with hysteresis is not a problem (LM2903 comparator with positive feedback) but for contact cleaning at 18V I'am not sure wich is the best way for implement it.
Now, in my design, with external trigger we change the voltage sourcing from 5V to 18V (small pulse of 0.5mS) and I filter it with RC filter befor the comparator.
Below my actual schematic of circuit.
Does someone has already implement it?
Any suggestions?
Thanks for any suggestion.
Alberto
my customer ask me to realize one digital input (the pin source the voltage to make reading) with large hysteresis and some 18V pulse for contact cleaning.
For make digital input with hysteresis is not a problem (LM2903 comparator with positive feedback) but for contact cleaning at 18V I'am not sure wich is the best way for implement it.
Now, in my design, with external trigger we change the voltage sourcing from 5V to 18V (small pulse of 0.5mS) and I filter it with RC filter befor the comparator.
Below my actual schematic of circuit.
Does someone has already implement it?
Any suggestions?
Thanks for any suggestion.
Alberto
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