SmartThings Community

Powering a door/windows sensor with constant power supply?

#1

Has anyone tried powering a 3V door sensor to avoid using batteries?

I’m thinking a transformer will not work as the current output is not precise and will burn the sensor. Possibly a linear power supply might work like this one https://www.sparkfun.com/products/114 ?

Any ideas?

0 Likes

#2

Quite a few people have done this. You can find project reports in the quick browse list in the community – created wiki, then look on the list for power options. :sunglasses: I think most of the ones converting battery powered to mains powered were for presence sensors, so you might specifically look for those.

http://thingsthataresmart.wiki/index.php?title=How_to_Quick_Browse_the_Community-Created_SmartApps_Forum_Section#Quick_Browse_Links_for_Project_Reports.2FQuestions

2 Likes

(Robin) #3

If you’re planning to run wires, maybe consider Konnected… that way you can use regular (cheap) alarm sensors and no batteries.

0 Likes

(Michael) #4

Did this with a contact sensor and a temp sensor:

Plan to try it try it on an Iris motion sensor over holidays.

0 Likes

#5

Nice, did not know about the Wiki, tons of stuff there thanks for the link

1 Like

#6

I’m planning on installing a driveway detector like this one

The receiver has a 12-volt relay to which I’ll install another relay that will act as the switch for a z-wave door sensor. I wanted to wire the power source instead of using the batteries. Batteries usually last years but the driveway has more movements so they may drain faster.

0 Likes

#7

Nice, this is the type of wire I was looking for but it is essentially the same thing as I saw on sparkfun (link above).

The board is $10 and it needs a power supply <40 volts so essentially any spare transformer with a 5.5mm jack (or change it to a 5.5mm male for $3) will do or buy a new one for $5.

0 Likes

(Ray) #8

I did similar thing to the Iris Motion sensor. This sensor is a little weird when over voltage. It will crash the ST app. I know you said 3.3V but be sure it’s not over. I used a variable Input/output voltage board similar to the one in your project.

2 Likes