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Triggering power supply using relay module

Triggering power supply using relay module

Triggering power supply using relay module


I'm working on an application to install door hold-open devices in a facility which does not have a fire alarm control panel. The facility does have smoke alarms installed. The intention is to remove power to the door hold-open devices during a smoke alarm condition.

I'm planning to power the hold-open devices using a regulated power supply which has a fire/emergency alarm release feature. Then use a relay module between the smoke alarm and the power supply to trigger the power supply to remove power to the hold-open devices during an alarm condition. I've attached the datasheet for the relay module and the regulated power supply for reference. I'd appreciate if I could receive some comments / insights for this design on any operational or compatibility issues.

Thank you.

RE: Triggering power supply using relay module

You will not be "triggering the power supply to remove power" if you are using the "F terminal" gambit. You are simply interrupting the DC output of the supply via the Normally Closed contact provide by the Kidde appliance.

The supply DC output is rated at: No more than 650mA usage and the Poly fuse protecting the DC output is rated at 2.5A.

The Kidde output relay (N.C. contact) I presume you're using, is rated at 5A. I see no issue with what you propose as I understand it.

Is 650mA enough to hold all the doors open?
BTW, I would certainly NOT have the normal load on a 650mA supply be more than about 500mA.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Triggering power supply using relay module

Thank you for your response.

I intend to connect six (6), 12/24VDC, 40mA (max) door hold-open devices to the 1A power supply. I expect a max. load of 240mA which should be within capacity of the power supply.

RE: Triggering power supply using relay module

Have at it. My college science building had almost 200 doors held open magnetically. When the power blinked you could hear everyone of them on all five floors slam about 3 seconds later.

Keith Cress
kcress - http://www.flaminsystems.com

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