Avoid the spurious relay switching

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gmarocco

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In order to avoid the spurious relay switching, I would like to build a control in such a way that the relay stays in the excitated state for 10 seconds after the control signal has gone low. I would like to build such a control with a single coil bistable relay. Does the following description make sense?

The relay set comand is given by the input signal . In order to build the reset signal, I would like to use a monostable with a time constant of 10 seconds . The output of the monostable is an input of a NOR gate . The second input of the NOR gate is the input signal. the output of the NOR gate is the reset signal.

Are there other driving method apart from the H-bridge in order to drive a single coil bistable relay giving separate set and reset signals?
 

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If the drive circuit operates well, there is no concern of "spurious" relay operation.
Relay coils are best driven by MOSFETs, and across the coil, connect a reverse diode so "swallow" overvoltage pulse when he current is cut.
 

"Are there other driving method apart from the H-bridge in order to drive a single coil bistable relay giving separate set and reset signals?"

For single coil bistable relays, you have to reverse the coil's polarity. So if you don't want to use a bridge, then you would have to have a negative voltage source.
 


Unless you use A "POLARISED" relay, no special care is needed.
 

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