normally open or closed contact?
- Thread starter dbaplaya
- Start date
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You might use a NO contact on a door alarm that may sound when the door is opened
it is exactly as it sounds. Your roller shutter contact will normally be closed.
What is normal ?
The normal state for switch or the normal state for the protected door.
In most cases the closed door presses on the switch, It is normal for the door to be closed and pressing on ( or otherwise operating ) the switch. The switch is then NOT in it's normal state.
Hence with the protected door closed the switch's Normally Open contact is closed.
The normal state for switch or the normal state for the protected door.
In most cases the closed door presses on the switch, It is normal for the door to be closed and pressing on ( or otherwise operating ) the switch. The switch is then NOT in it's normal state.
Hence with the protected door closed the switch's Normally Open contact is closed.
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Normally I would be doing NC operations and in open circuit state the alarm activates.
Its likely your gate wants to be shut?
So as long as you program your system to activate the alarm system/ notification when its gate has been opened the actual sensor doesn't matter as you program accordingly.
so in sparkymarka example, the circuit needs to be closed when the gate is open so the circuit flows and the bell rings, in this case the device is NO, normally open when gate closed and closed when gate is opened.
Its likely your gate wants to be shut?
So as long as you program your system to activate the alarm system/ notification when its gate has been opened the actual sensor doesn't matter as you program accordingly.
so in sparkymarka example, the circuit needs to be closed when the gate is open so the circuit flows and the bell rings, in this case the device is NO, normally open when gate closed and closed when gate is opened.
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