Hi Im working on a small project. A 12v normally closed relay is connected to a water pump. When voltage is applied to the realy it opens (This is considered a Alarm Condition), the pump shuts off and an audible/ visual alarms activates. That all works fine. My question is how can I build in a reset button that will close the realy when its back in a non alarm condition. Only When a reset button is pushed that the relay will go back to normally closed. Thanks as always

 

Is there any method that is now available to reset the relay and thus clear the alarm? This question of course assumes that the relay alarm is an existing system and you wish to modify its behavior.

hgmjr

 

What keeps the relay from closing again when power is removed from the coil?

 

What keeps the relay from closing again when power is removed from the coil?

U-hu. I had the same question, and another one: is it a latching relay?
Post the model of your relay.

 

Thanks for your replies. Its not an existing system. The relay is connected to a 3904. Basic stamp feeds the 3904 which switches the relay in an alarm condition. The relay power source is a standard 9v battery. Also the 9volt powers the audible/visual alarm. Relay is a 12v radioshack. What Im trying to accomplish is building into the project a reset button that only when pressed that the water pump will get its 120vac. When its out of alarm, and back into a normal condition pressing the reset button will restart the circuit. Thank you

 

Can't you just wire from GND through the reset button and a pull-up resistor to an i/o pin and let software do the rest?

 

Can't you just wire from GND through the reset button and a pull-up resistor to an i/o pin and let software do the rest?

Wire the sensor that sets off the alarm to the basic stamp too.