Movement sensor turns on light
Hi,
There is a light in the staircase outside our apartment, and for some reason I never get to change the lightbulb (to my wife's irritation, and my annoyance
.
So I thought I'd make a timer/relay circuit with the PIR sensor to have the light go on when there is movement in the staircase.
This timer is easy to build and requires just a few components. In fact, the most expensive part of the circuit is the 12V battery replacer!
The main parts of the circuit are:
* PIR sensor from Parallax. This device outputs a high signal when it senses movement
* 555 Timer. Easy to use and cheap IC to control timing.
* 7805 Regulator. To reduce 12V to 5V for some parts of the circuits.
* 12V relay to switch the mains electricity on
It took me about 10 hours to complete, including attachment to the wall and mains electricity.
Since I don't have access to PCB's, I just left the whole thing on a breadboard, inside a wooden box I found in the atic.
I have a 10ohm resistor at R1, so the light stays on about 2 minutes.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Don't worry. Be happy
There is a light in the staircase outside our apartment, and for some reason I never get to change the lightbulb (to my wife's irritation, and my annoyance
.So I thought I'd make a timer/relay circuit with the PIR sensor to have the light go on when there is movement in the staircase.
This timer is easy to build and requires just a few components. In fact, the most expensive part of the circuit is the 12V battery replacer!
The main parts of the circuit are:
* PIR sensor from Parallax. This device outputs a high signal when it senses movement
* 555 Timer. Easy to use and cheap IC to control timing.
* 7805 Regulator. To reduce 12V to 5V for some parts of the circuits.
* 12V relay to switch the mains electricity on
It took me about 10 hours to complete, including attachment to the wall and mains electricity.
Since I don't have access to PCB's, I just left the whole thing on a breadboard, inside a wooden box I found in the atic.
I have a 10ohm resistor at R1, so the light stays on about 2 minutes.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Don't worry. Be happy
Comments
Attached picture of what it looks like in the hallway. You can see the PIR sensor sticking out at the bottom.
Last post I said 10ohm, I meant 10Mohm for R1.
The transistors T1 and T2 can be replaced with any general purpose NPN transostors.
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Don't worry. Be happy
James