PIR Motion Sensor Security Circuit - Duration Adjustable - Project#1 Electronics Learning Boar

About: Hi there! My name is Patrick, and I am an electronics engineering technician who works full time as a lab tech, and part time as an electronics engineer/salesman. I own an ebay store, and two websites, whic...
Hi Everyone!
I've been working very hard to make electronic block tutorials for my youtube subscriberes, as well as potential buyers of my electronics learning board.  The board has many different blocks, and there are 11x tutorial videos that I have to show you how each of them work. Each tutorial has a theory and lab section, so that the user can work through the theory, and witness the result!  This is a VERY simple, and introductory circuit.  The below video shows you how easily the circuit is implemented on the learning board, and talks about the block diagram of the circuit.  The following sections will talk about each of the blocks involved, and each video tutorial has a theory and lab section.  

The PIR Motion Detector Circuit:
For this project, we will be using our PIR motion detector module. You need to follow the above video, which shows you how to hook it up, and how to calibrate sensitivity.  Once the 5v pin and the ground pin of the PIR module has been connected to the board, you can connect the PIR module output to the LED pin indicator.  When the PIR module senses motion, this LED will light up.  You need to calibrate sensitivity using this LED.  Up[on power up, the PIR module is unstable, and takes about a half a minute to settle.  From there, do as I do.  Play around with it.  You can even test it out in the dark!  Just be careful not to trip!   Once you have calibrated your PIR module, connect a two pin shorting jumper to the BUZZ pins on the actuator pin block.  This selects your buzzer.  Connect the PIR module OUT pin to the ACT pin on the main pin block.  From there, whenever the PIR sensor senses motion from a human being, the buzzer should ring for a short duration (Depending on how you’ve calibrated it).  When calibrating the PIR sensor, be patient.  It takes some time to get used to the process.  Once you’ve done it one time, you’ve done it a hundred!  MAKE SURE TO TAKE CARE WHEN HOOKING UP THE PIR MODULE!  If you connect the ground line to the 5v line on the board, and the 5v line on the PIR module to the ground line on the board, you will fry your PIR module.  The following video goes over the block diagram, and plug-ins, while the following sections offer detailed tutorials on each block!

Step 1: The 7805 5v Regulator

Our digital circuitry may very well be sensitive to over-voltage.  Both the PIR module and the piezo buzzer cannot handle more than 5v, so we need to regulate from 9v down to 5v, as our input voltage is a 9v 1000mA wall adapter.  Most projects like this would require a 9v battery.  How to we easily regulate down to 5v?  Easily!  With the help of our trusty and inexpensive friend, the 7805 5v regulator IC.  This IC has an input port (1), a ground port (2), and a regulated output port (3).  The power supply circuit, including the 7805 is talked about in depth in the below video!  In order to regulate down to 5v, you need at least 7VDC at the input pin.  If after watching this video, you have any questions, please do not hesitate to post them below!  I'll do my best to answer!

Step 2: The PIR Module

The PIR module has three pins: 
5v - 5v Power supply line
OUT - Output Line
GND - Supply ground
The below tutorial talks about how to calibrate your PIR module, and how to connect it to your circuit.  The 5v line on the PIR modules connects to the 5v supply line on the main pin block, the output pin connects to the buzzer driver on the pain board (Talked about in the following section), and the ground pin connects to the common ground line on the board.  Follow along with the tutorial below, and you will see this baby in action!

These PIR modules are pretty generic and can be found all over the place for relatively little cost.  Usually $5 or less.

Step 3: The Piezo Buzzer Driver Circuit

While the PIR output can easily output enough current to properly drive our Piezo buzzer on its own, many chips cannot.  In this case, you can use a transistor driver.  In the video below, you will not only see how you can drive a buzzer to full potential, but how to drive relays, motors, and speakers with a transistor driver.  In this case, we employ the trust 2N2222 NPN transistor.

The piezo buzzer is an "active" buzzer.  Many buzzers require a an applied frequency within the audio range to operate properly.  Active buzzers simply need a power supply to be added, as there is an internal oscillator circuit that power up when 5v is applied.  The transistor driver acts to complete the circuit when power is applied from the output of the PIR module to the base of the transistor through a protective resistor.  If this happens, then current from the collector of the transistor can flow through to the emitter, which is connected to the ground line.  If you watch the video below, this will be explained in full.

Once you've watched the video, you should be able to use all three blocks to create your own doorbell circuit!  With ease!  On your breadboard!

Step 4:

By now, you should be able to do this on your own!  It is a simple, yet introductory circuit, and I hope that you've been able to learn something.  If after you've watched the videos, and you've created this circuit on a prototyping board, or a breadboard, and you do not get the result that you wanted, talk to me.  I'll try to help you to figure out what is going on!

We can also be reached through:

I created this learning board so that users can watch the block electronics videos to learn how the electronics work.  It is a practical board, and while I'd like to interest you, I don't want for you to think that this is merely a promotional add.  I want for you, the user, to be able to use the tutorial blocks to create your own circuitry.  The learning board merely acts to save time relative to setting all of the circuits out on a breadboard.  The below video shows you some of the other project examples that can be achieved with this learning board!

Pre-Order (If you are interested): http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=171081822708



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