Intro: How to Make a Motion Activated On/Off Light or Electronic Appliance
i'm entering this for the epilog challenge V and the kit contest .So don't forget to vote for me in the contests.I would like to win one of those laser cutters to make enclosures, parts and engraved materials for my projects and i could defenitely use the laptop tablet and the parrot drone.Thank you for viewing and once again don't forget to vote.
Step 1: Components :
555 timer x1
LM741 opamp x2
4017 counter. x3
100 ohms x1
2.2uf (microfarads) electrolytic capacitor x1
0.1uf ceramic disc capacitor x1
5v spst relay
9v battery(if you're gonna use an adapter you don't need the 9v battery and snap)
9v battery snap
PCB board x1(the following is only if you're gonna solder it)
solid core wire .
DIL sockets(if you're soldering)
a breadboard(if you want to prototype it)
*the picture is for representation purposes onlyand does not represent the components used in this project and i do not own the copyright of the image
Step 2: The Schematic:
The schematic is given below.it would be better if you built it in 3 different parts-like i have done it.
The 555 timer circuit:
-connect pin2 to pin6
-connect pin 4 to pin v+
-connect pin 1 to V-
-connect pin 8 to V+
-connect a 47k resistor between pins 6 and 7
-connect a 100k resistor(you may have to experiment with this value)between pin 7 and V+
-connect the positive of the capacitor to pin 2 and the negative of the capacitor to V-
-connect pin3 to the emitter of the 2n2907 transistor.
the first part is complete
The proximity sensor:
-connect pin4 to V-
-connect pin7 to V+
-connect a 1M reistor between V+ and pin2
-connect a 1M resistor between V+ and pin3
-connect a 1M resistor between V- and pin2
-connect the cathode(shorter lead) of the photodiode to V-
and longer lead(anode) to pin3
-connect a 1.5k resistor between pin6 and the base of the transistor.
_______the second part is complete
The 4017 counter
-connect pin8 to V-
-connect pin16 to V+
-connect the anode(the end of the diode with no band) of 1n4148 diodes from pins 3,4,5 and 10 and connect the cathode(the banded end of the diode is cathode) of all the diodes.
-connect a 1k resistor between the connected cathodes of the diodes and the base of the 2n3904 transistor
-connect the collector of the 2n2907 transistor to pin 14
____the third part is complete
identify the pin contacts of the relay
-connect the emitter of the 2n3904 transistor to V-
-connect the collector of the transistor to either of the pin on both sides of the common pin of the relay.
-connect the other pin on the other side of the common pin of the relay to V+
-connect the cathode of the diode(banded end) to the pin where V+ goes into and the un-banded end(anode) to the collector of the transistor(pin on the other side of the common pin of the relay)*
-connect a 0.1uf capacitor between V+ and V-**
-connect a 0.1 uf capacitor between the 2 pins on both sides of the common pin of the relay**
HANDLE THIS PART OF THE CIRCUIT WITH EXTREME CAUTION :!!(-make sure you are not working with the relay when the 220v ac supply is on.)
-connect one of the two lines of the 220v ac supply to the common pin of the relay
-connect the other line of the 220v ac supply to your bulb,cfl or appliance.
-connect the NO pin(normally open) of the relay to your appliance or bulb (if you don't understand this part see the schematic diagram)
-connect the 9v battery with its polarity properly connected.
-in case you are using an adapter use an 100uF electrolytic capacitor between V+ and V-
-in case the circuit's not working properly move on to the next step
*the diode is to make sure the relay does not turn off or on in case of voltage spikes
**the ceramic disc capacitor is used as a noise filter
in case you want to download a pdf of the file the download is below,it's called AMTFL(analog motion triggered fluorescent bulb)
Step 3: Tips,Tricks ,Precautions and Sources of Error!
Tips and tricks
-it's not that you have to switch an AC 220v load,you could even use an dc supply to light up your homemade table light or to roll up and down your venition blinds of your window.if you have made a version of this post a few images in the comment box or leave a link for me to see it.
Precautions and sources of error
Make sure you are NOT working with the relay while 220vac power suply is on.this is an absolute must.I am NOT responsible if you hurt yourself.BE CAREFUL AND CAUTIOUS WHILE WORKING WITH AC POWER SUPPLIES.
-make sure you do not connect any two wires unwantedly .
pin4 runs over pin 3 and pin 2 to pin6 but IS NOT CONNECTED TO EITHER OF THESE CONNECTIONS .if you have any doubts leave it in the comment box ,thanks to steveastrouk and Josehf Murchison for helping me troubleshoot my circuits and once again be careful and in case i've made a mistake please notify me by leaving a comment and thanks for viewing my project.