Infrared motion detector circuit
Description.
Here is the circuit diagram of an infrared motion detector that can be used to sense intrusions.Infra red rays reflected from a static object will be in one phase, and the rays reflected from a moving object will be in another phase.The circuit uses this principle to sense the motion.
The IC1 (NE 555) is wired as an astable multivibrator .The IR diode connected at the output of this IC produces infrared beams of frequency 5Khz.These beams are picked by the photo transistor Q1 .At normal condition ie; when there is no intrusion the output pin (7) of IC2 will be low.When there is an intrusion the phase of the reflected waveforms has a difference in phase and this phase difference will be picked by the IC2.Now the pin 7 of the IC 2 goes high to indicate the intrusion.An LED or a buzzer can be connected at the output of the IC to indicate the intrusion.
Circuit diagram with Parts list.
- Comparators IC2a and IC2b are belonging to the same IC2 (LM1458).So the power supply is shown connected only once.No problem.
- When there is disturbance in the air or vehicles passing nearby,the circuit may get false triggered.
- POT R5 can be used for sensitivity adjustment.
thank u.and it is very good project
Thanks for your wonderful project
thanks for your help
I set up the circuit but for some reason the light I placed at the output (pin 7) stays on all the times. Do you have any suggestions of why this might be?
looking for IR based circuit which can detect moving as well as stillobjects.
If yes , pl. revert back
Where do you give the power supply to the transmitter ?
how will the diode work without giving any power supply ?
that can be solved by adjusting the POT R5
oops! mistake from my part
you can supply 9 to 12V to the transmitter circuit .
i have corrected the circuit diagram
Please some boby help me to find a circuit that change the voice/Sound pitch like girl to boy, like young man talking in old man sound pitch.
can some body help me to find that
I Assume pin 4 on IC2b is to ground. what does the 50K pot (R5) do. I assume a LM393N will the same job as LM1458
Oops
In previous question I meant what does the 50k pot (R7) do.
Does pin 4 on IC2b go to -ve pole of battery
To Jeffers
By connecting pin4 to ground, the opamp will still work but not correctly.
R5 is to do with negative feedback for the op amp. It adjusts the amount of gain for the op amp.
Looking at the datasheets, I would say that yes the LM393N and the LM1458 are compatible, pin for pin.
Thanks Twits4Twats
Now understand that I need a split supply 12v+-0-12v- to the reciever. Are the 50K pots R1 and R7 used to match the pulses of the IR emitter and the photo transistor
Excuse the newby question but what is the difference between -12v and ground.
does this circuit really works? have you tried this?
ground means zero potential.
-12V volts will be 12V lower than the zero potential.
Steve says:
June 24th, 2009 at 11:28 pm
Excuse the newby question but what is the difference between -12v and ground.
If you appreciate that ground is zero volts and +12V is therfore 12v higher than ground. -12V is then 12V lower than ground. Bascally, for some op amps to work a split rail supply is required (+12V and -12V).This can sometimes be bypassed by using an op amp that works off a single supply rail.
Allthough the circuit above requires a single rail supply for the 555, it does require a split rail supply for the op amp.
Try to google split rail supplies.
Jeffers says:
June 18th, 2009 at 7:49 am
Thanks Twits4Twats
Now understand that I need a split supply 12v+-0-12v- to the reciever. Are the 50K pots R1 and R7 used to match the pulses of the IR emitter and the photo transistor
In laymans terms, R1 (in conjunction with C1) sets the RC time constant on the 555 which in turn sets the 555 pin 3 output to how long it switches the Infra Red LED on for. In this circuit it is calculated to be 5KHz. Simply put, you can use R1 to alter the frequency of the IR LED.
R7 is used to set the value of the non inverting input (pin 5)of IC2b. Simply put, when pin 6 of IC2b then mathes pin 5, the output of pin 7 will go high.
To answer your question, allthough not entirely correct, R7 is used to match the pulses of the emiiter and receiver.
Thanks Twits4Twats
To recap then if I put a buzzer or LED across ground and pin7 on IC2b. Set R1 and R5 to mid range and then adjust R7 at some point the buzzer should start to buzz if something moves in front of it. also if it have a split supply 12-0–12 then I need a voltage drop of 24 volts total ie a 24 V battery supply split from 12V+ to 12V -
Cheers
Jeff
hai, can i use L14F1 or L14F2 at the receiving part?
yes
infra red transmitter is ok,but receiver output is giving me a constant voltage of +12v,whats the problem?
Thanks Twits4Twats
To recap then if I put a buzzer or LED across ground and pin7 on IC2b. Set R1 and R5 to mid range and then adjust R7 at some point the buzzer should start to buzz if something moves in front of it. also if it have a split supply 12-0–12 then I need a voltage drop of 24 volts total ie a 24 V battery supply split from 12V+ to 12V -
Hi Jeffers
Sorry for not responding sooner. I haven’t built this circuit so please don’t quote me for accuracy but I can’t see why it won’t work.
To answer your first question. Lets get this straight – ground is zero volts and not the -12Volts that IC2b uses. So if you were to conect a 12V buzzer from pin 7 of IC2b to pin 1 of IC1 or pin 3 of IC2a, then you should get some noise at some stage like you say. A point to note though, if you don’t get sound at all and you have observed the voltages correctly,is your buzzer self driving or does it need to be driven. Piezo buzzers work on an oscillating frequency. This means that the polarity of their voltage supply needs to be reversed at a certain frequency to get sound from it. If it is self driven, then it has a small circuit built in to do this polarity reversal. If it is not self driven, you have to then provide it with a circuit to do this polarity revesal.
If you were to use an LED instead of a buzzer, as long as you connected it to the same points as above, you will be allright. You would have to add a 1K resistor in series with the LED though or it will burn out. General rule of thumb is 1K for 12V.
Your second question. Yes, you could use a 24V supply to generate your +12V and -12V. See the link below.
http://www.headwize.com/projects/cmoy2_prj.htm
The supply can be anything. A battery or a PSU.
As a matter of interest, why do you want to build this circuit?
what will be the orientation or placement of the ir diode and photo transistor?
do i need to place it face to face with each other.
how will the ir diode work when somebody pass by on the ir diode?
can i used a 9v battery for all the supplies?
i think 12V will be a better option.
IR diode and photo transistor shall be placed face to face.
I am doing a project at my local college and was hoping to get the components list of this circuit. Also if possible what would be the best method of linking it to another circuit?
Thanks for this great circuit!
@admin
Can u kindly give me the circuit’s computer simulation file. actually I am making this circuit as my 4th semster OP AMP project.
I need ur help.
Thanks.
And I only have 4 days to built. Please help…
I want description on 10uh.
Kindly help…
I need the simulation of this circuit!
Thanks..
Hi Twits4Twats
The reason I wanted to make the circuit was for a holiday in Kenya the idea being to leave it set up to fire a camera at night for any small nocturnal creatures that may have been passing. As it was the grounds were so well manicured that only the odd rat or squirrel would have come past i’m sure. Got loads of other wildlife though !!!!!!!!!!!!
I’ve just noticed that pin 7 is not marked on IC1 in the diagram but a connection appears to be going to nothing. I assume they are one and the same
Cheers
jeffers
can i connect camera in the output pin 7?? im doing my project in my local university with the same title as above. and my suggestion is to connect camera and the picture wuill send to the mobile phone.. anyone got any suggestion on how to do it?
It is almost impossible to interface a digital camera with this circuit.
can we use transistors in place of IC2 to drive a 8 ohm, 1W speaker??
we can use….8 ohms speaker instead of led…
Loud speaker is not a good option. An LED or a Buzzer is the best.
Speaker is not a good option.
Speaker is not a good option.
Hi Twits4Twats
The reason I wanted to make the circuit was for a holiday in Kenya the idea being to leave it set up to fire a camera at night for any small nocturnal creatures that may have been passing. As it was the grounds were so well manicured that only the odd rat or squirrel would have come past i’m sure. Got loads of other wildlife though !!!!!!!!!!!!
I’ve just noticed that pin 7 is not marked on IC1 in the diagram but a connection appears to be going to nothing. I assume they are one and the same
Cheers
jeffers
Hi Jeffers
Sorry dude for not responding sooner! I just don’t have time (wife and 2 kids…lol).
Pin 7 – I just look at the schematic and naturally assume the pin locations. You are 100% absolutley correct. Pin 7 isn’t labled and should be the one that isn’t labled. ***ADMIN- PLEASE NOTE***. IC1 forms an Astable 555 timer circuit and pin 7 is typically the one you identified.
You are correct about the Infra Red sensitivity. At best you are talking a few inches. This circuit is meant for close proximity however if you could upgrade the transmitting LED you could have a very good movement detector. If you Google around a bit I have seen versions for around 50m.
can i connect camera in the output pin 7?? im doing my project in my local university with the same title as above. and my suggestion is to connect camera and the picture wuill send to the mobile phone.. anyone got any suggestion on how to do it?
Jana
Pin 7 is not for an output of IC1.It is for the timing of the 555.
The fun in electronics is that you can achieve almost anything with a simple circuit.
Yes you can attach a camera to this circuit however more details would be required of what you are trying to achieve so the circuit can be modified.
Submit details!!!
can we use transistors in place of IC2 to drive a 8 ohm, 1W speaker??
Carrion
Presumming by your question, you wish to scare off creatures of some sort once they have activated the sensor. I would still use the op amp to drive the amplifier after all, that is what the op amp was designed for.
Submit some details of what you want to achieve.
ADMIN
Keep up the tutorials – I think you have a very good approach.
Any way the website can be updated so that I can receive email for response to postings?
Hi Admin,
I’m doing this for my final project and have been trying to work it since weeks ago. My due date is very near and I have a problem with the receiver circuit. The LED lights up as soon as the power supply is on. I couldn’t find the phototransistor L14F but I was told another one would work the same. Please help me on this.
I hope it’s okay to contact you via email. Or if not, I will be looking forward to your reply here. Thankyou so much!
what about pin 7 in IC 555???????
Thank u all
Hi Admin,
I’m doing this for my project and my due date is near. I’m facing a problem fixing the power supply. This is my first time facing a -ve voltage supply. Please enlighten me on how to connect it as my current way – by bringing two 12V supplies to parallel does not seem to work. Would I need a voltage regulator for this circuit?
Reply to Tracie
A +12/-12 V dual power supply circuit suitable for this project is shown below.
http://www.circuitstoday.com/regulated-dual-power-supply-circuit. Make this power supply circuit and connect it to the motion detector circuit.
If you have further doubts, then comment in here. I will give you a more detailed reply.
thanks.
admin
hi Admin,
i’m doing this for my project (just like the others)… my problem is that once i turn the power on (i did the schematic you gave for a dual power supply circuit) the LED lights up immediately… what might be the problem… please help… my project is due a week from now… THANKS… in advance…