Controlled Outlet V1.1
author: mathieusan
2 layer board of 1.49 x 1.87 inches (37.8 x 47.5 mm)
Uploaded:
June 8th 2020
Shared:
June 8th 2020
Total Price:
$13.90
Optocoupler to control a 120VAC 15A outlet from a smoke detector. Uses a standard hardwire smoke alarm which takes advantage of its 9VDC output “sensor line” sending high when there’s a fire. The board routes the 9V to an optocoupler. The isolated side is a latching soft switch using NPN and PNP transistors.
The outlet will be live and conduct during normal operation (when there is no fire). When triggered, it will latches the relay to cut power to the outlet. The soft latching is needed to ensure that any change in the smoke alarm trigger will not impact the state of the switch (such as the fire alarm burning while still a fire is going on). The board uses the normally open ends of the relay, such that if the board would burn as well, the relay would naturally stays opened.
The board has an additional output with pull down resistor to allow a generic microtrontroller to also pick up the fire alarm trigger and do some second level action (such as sending an email, or controlling something in a less critical fashion; home assistant status for example)
Relay: RT314F12 Power Supply: RAC05-24SK Optocoupler: ILD615-1X007T Transistors: MMBT4401 and MMBT4403 most surface mounts are 1206 R4 needs to be .25W; the other resistors are ok with .125W One capacitor (220uF 25V) is in a SMD 2924 package: TCN4227M025R0100. This C1 capacitor is to allow a delay of about 200ms to avoid a false alarm.
Optocoupler to control a 120VAC 15A outlet from a smoke detector. Uses a standard hardwire smoke alarm which takes advantage of its 9VDC output “sensor line” sending high when there’s a fire. The board routes the 9V to an optocoupler. The isolated side is a latching soft switch using NPN and PNP transistors.
The outlet will be live and conduct during normal operation (when there is no fire). When triggered, it will latches the relay to cut power to the outlet. The soft latching is needed to ensure that any change in the smoke alarm trigger will not impact the state of the switch (such as the fire alarm burning while still a fire is going on). The board uses the normally open ends of the relay, such that if the board would burn as well, the relay would naturally stays opened.
The board has an additional output with pull down resistor to allow a generic microtrontroller to also pick up the fire alarm trigger and do some second level action (such as sending an email, or controlling something in a less critical fashion; home assistant status for example)
Relay: RT314F12 Power Supply: RAC05-24SK Optocoupler: ILD615-1X007T Transistors: MMBT4401 and MMBT4403 most surface mounts are 1206 R4 needs to be .25W; the other resistors are ok with .125W One capacitor (220uF 25V) is in a SMD 2924 package: TCN4227M025R0100. This C1 capacitor is to allow a delay of about 200ms to avoid a false alarm.