Street light circuit.
Description.
The circuit diagram present here is that of a street light that automatically switches ON when the night falls and turns OFF when the sun rises.In fact you can this circuit for implementing any type of automatic night light.
The circuit uses an LDR to sense the light .When there is light the resistance of LDR will be low.So the voltage drop across POT R2 will be high.This keeps the transistor Q1 ON.The collector of Q1(BC107) is coupled to base of Q2(SL100).So Q2 will be OFF and so do the relay.The bulb will remain OFF.
When night falls the resistance of LDR increases to make the voltage across the POT R2 to decrease below 0.6V.This makes transistor Q1 OFF which in turn makes Q2 ON. The relay will be energized and the bulb will glow.
Circuit diagram with Parts list.
Notes.
- POT R2 can be used to adjust the sensitivity of the circuit.
- You can use bulb of any wattage ,provided that relay should have the sufficient rating.
- The circuit can be powered from a regulated 9V DC power supply.
- Click Here! to get the power supply circuit for this project.
- The relay K1 can be a 9V SPDT relay.
Respected Sir, can i use IR sensor for automatic street light? How?
sir i need to use microcontrooler in the circuit….plz help me
hi! is 100K preset value of R2 or it is a set value??? if it is not then what is the set value???
sir, we require an automatic street light circuit using ldr and npn transistors in darlington connection &relay .please send us the report.
i want to inverter diagrom
Hi Ram SPDT is singe pole double throw contact, nothing but a relay with a change over contact. (volt DC is the supply for the circuit to operate. It should have been shown as 9vols DC plus (+9volts) and negative to common shown as ground (emitter of Q1 & Q2).
iam not able to understand about SPDT relay and 9V dc plz give me the clarification
pls suggest me component for ldr and pot resistor to simulate this circuit in pspice
Sir, pls help discuss on the issue of the movement detector. PLEASE!
Sir, I haven’t heard from you yet. PLS IT’S URGENT!
Hi Ishan you can use 2N2222, 2N2221, 8050, 2N1711, BC167, BC237, BC317 any NPN small signal transistor can be used.
Sir, It’s not possible to find BC 107 in my country. is there any other equivalent transistor for this BC 107 ? thanks
Infact how do we go about the movement detector circuit? what form of sensor can be best used? should it be sound or metal or what? pls it’s urgent.
Owing to your comment on August 13th, I would like you to please send a circuit that will give room for a movement detector in your circuit, such that during off peak periods say after 10pm, the illumination will be reduced or using the 50% idea as u’ve said, but whenever an obstacle gets nearer, it gives full illumination or 100%.
my email add: tofman2020@yahoo.com
Pls it’s urgent.
Hi Luckydile 220uF will be a very large value delay will be larger, still you can try. if 4.7uF is available you can try.
sir pls,i’ve got this topic as a project.now,the 10microfarad 12V capacitor u added to cut off transient responses is not available around here.pls tel me another capacitor that wil do the job or wil 220microfarad 16V capacitor do? Thank you sir.
pls sir,i’ve got this topic as a project.now,the 10microfarad 12V capacitor u added to cut off transient responses is not available around here.pls tel me another capacitor that wil do the job or wil 220microfarad 16V capacitor do? Thanks so much.
sir i am student of electronics engineering i have need component of the ultrasonic motion detector.
HAY FRIENDS I AM STUDENT OF THE LAST YEAR DIPLOMA ELECTRONICS ENGINEERING. I NEED FULL INFORMATION ABOUT THE STREET LIGHT CONTROLLER LIKE THE CKT DIAGRAM, BLOKE DIAGRAM ITS INTRODUCTION, APPLICATION, BLOKE DIAGRAM,AND GIVE THE INTRODUCTION ABOUT ALL COMPONENTS AND VARYFICATION ABOUT IN
IT.
Hi James you can connect 2nos hi bright white LEDs in series and a resistance of 47 ohms 1/4 watt also in series connect them in place of the relay shown, such that anode of LED is towards 9 volt +ve.
Hi there, great circuit! Can the relay be swapped for an LED. If so which way will it be connected?
Thanks
Hi Kecik you can but the circuit will not work if you shout near microphone the relay at the most can chatter, that is all.
sir, can i change the LDR to electret microphone.???
Hi Nandita for traffic sensing you can use Doppler Shift sensing method or IR movement detector or any movement detector. To avoid special circuits for florescent light dimming, use two lights in each fitting you need switch off one for 50% illumination. for switching you can use SSR or standard mechanical relays. You use a dark detector during dusk switch on both the lights after 4 hours it will switch off one light and with movement detector it can come on. once no movement is detected it will again switch off. during dawn both will go off. This will work when suddenly it becomes dark even during day time due to dark clouds
Sir, Im a final year Btech student, and would like to do an extension of this project. ie..The streetlight is fully bright during the peak hours of traffic, say from 6pm to 10pm.After 10pm it automatically goes to a power saving mode with 50% brightness, and then when a vehicle or pedestrian approaches, it again goes to 100% brightness. Hoping for your valuable suggestions.
give the circuit for mobile controlled street light system………….?????????
thank you sir, this very useful circuit to me .i have more intrest about electronic projects .
Sir, I assembled the above circuit along with the additions suggested by Sri Seetharaman (May 14, 2011 above -to avoid chattering and transient response)and using the light in my courtyard and it is working excellent. Whenever we go out (by locking the house) we switch it on and by the time we return during night, the light automatically is on during dusk. Very good facility and security to the house. The circuit is simple and better than other circuits which use a Triac (I also assembled the same) wherein I find lot of flicker in the incandescent light during the transition period(day/night). I Thank Circuitstoday for giving the above circuit.
Thank you sir, Thanks a lot!!
Hi Abhijan Pl refer my comment dated 28th April. Adjust R2 for you requirement. If you want small delay you can add a capacitor of 10 to 100uF between Q2 base and common ground. If you want to have a small difference in light level between switching on and off add a 100k resistance between Q2 collector and Q1 base.
Hello sir. The circuit is really helpful. I had a doubt though. I have a 12V bulb and a DC supply from the battery of the vehicle itself. How can I modify this circuit so that I can use the LDR system to automatically switch on the light with decrease in Visible light!
Hi Edwardson you are right you can fix a 10uF 12 volt capacitor in parallel to R2 that will take care of transient response. This simple circuit itself is having enough hysteresis hence chattering will not be a problem. Still if you feel it is not sufficient can add around 1M resistance between Q2 collector and Q1 base.
Correct me if I’m mistaken but this circuit seems to be prone to at least two conditions:
1. “chattering” — when ambient light level is at or crossing the trip point, the relay/load can rapidly switch on and off, the reason being that there’s no hysteresis built into the circuit. For better performance the ambient light level at which the load is switched on will be slightly lower than the level at which it is switched off.
2. abrupt, transient, and large changes in ambient light level will “fool” the circuit into switching the load on/off. Example: during the night, lightning and car head lamps might make the circuit turn off the load for the duration of the high ambient light level. So there’s a need for a low pass filter to make the circuit reject these transients. A simple RC network connected to the base of Q1 might be sufficient.
thanks macha.
Hi Mouly no change is required you can increase the supply voltage to 12volt with 12 volt relay.
Dear Sir,i can only find 12v relay in my place.Can i use 12v relay?any changes should i make in the circuit.Waiting for reply
Hi
i am a final year student,i was given a project on the design of a street light using a low energy LED i dont know how to get the circuit diagram and also the procedure to follow in actualising the project.plz if you can help me with the circuit diagram send it to my email i need it urgently thank you in anticipation.email address:-
kings_ifeanyi@yahoo.com
Hi Rajashree + of nine volt is given to line indicated as 9V DC. – is given to the common shown as ground. BC 107 is a small signal NPN transistor in T018 casing. SL100 is a medium power medium current transistor in T05 casing. Since the relay used is 9volt the supply also should be minimum 9 volt to operate it.
Please tell me how 9v dc supply is given? And about sl 100 and bc 107? Why it is used and their properties? Please give the calculations of 9v dc suply to the circuit.
sir how can i connect relay in my ckt
Hi Deepanshu Q1 is sensing comparator and Q2 is relay driver.When the light is falling on LDR it resistance becomes low biasing Q1. it conducts the base bias available for Q2 through R3. Q2 stops conducting and the relay is switched off. once the light falling on LDR reduces its resistance increased reducing the bias for Q1 and stops conduction. since Q1 is not conducting the bias for Q2 is made available, the relay conducts and the light is switched on. The light sensitive level to operate the relay can be adjusted with preset R2.
sir,i m a ist year student…i want to know wat is the need of transistors in the above circuit…if possible,please send me details about the working of these two transistors….w8ing 4 ur reply..
thank you
hi,i am doing a project on this same topic with an extension that it has an automatic intensity control circuit. the brightness must be adjusted when any car or object passes the street light..waiting for your valuable suggestion
BC107 = 2N2222 = BC548
SL100 = BD139 = BD135
sir what is the replacement of bc 107 and sl 100… wala kc mabili d2 na ganyan
sir
i need the connection diagram of led street light b/c i need it to done in my country b/c as my country is a developing country and we use high power consumption lamp and they have not longer life so please tell me how to done this.
thank you
Sir can we design an intelligent street light controller which switches itself on when a vehicle is detected? and then switches off by itself after the vehicle passes away?
sir,
i used ur ckt n developed a ckt of automatic car headlight dipper…
thnx 4 uploading ur ckt….
having minor viva tomorrow…
will tell u how it went related 2 ur ckt…
sir ,
when a light falls on ldr its resistance increase and current increases then ldr has high resistance in the absence of light
then how the street light works
Hi Vikas 230volt AC to 15 volts SMPS are available in the market at reasonable cost. you can buy that and use with LED circuit. (why you require 15volts for the LED ?). can you kindly elaborate your requirement
Sir i am polytechnic stud. plese give me complyt cicuit diagram and project report to street light to 230 volt ac and pass to 15 volt dc supply for led
Sir, I am doing my diploma in industrial electrical, I have to make diagram using Contactor, RCD or MCB, Timer for automatic switch on, six 400 watt flood lights,
Hi bu i am just back from my pilgrimage you can use 2N2218 2N2219 BD135, 2N1711 any medium power NPN T05 casing or T0220 casing transistor will do.
pa ada alternatif SL 100
Is there any alternatif for SL100?
tanya ke seetharaman
pa ada ganti tuk SL 100,thanks
this project can make base on microcontroller?
respected sir can we make this project(microcontroller base street light control )?
if yes than how to implement it?give some brief information about circuit diagram?
i look forward for positive speedy reply.thanking you. sir it’s urgent.
can i use a single automatic switch for the whole street lightings? what type of sensor will i use? thanks in advance..
Sir,
Only 12v relay is available in our area so what modifications has to be done to make the circuit work with a 12v power supply.
Thanks.
how i mine going to use the street light to light up 15 point of light 200watt each.
Sir, Thank you very much for this circuit. I am a first year BTEC student. I have a question regarding the nine volts voltage applied in the light-detecting bit of the system. It is: How does the street light in our roads actually access a 9v supply? Do they use a step-down transformer and rectifier? Thank you sir.
Hi Sunita You can use the Dew sensitive switch appeared in this column in “Circuits Today”(which uses LM358 dual OP amp). You can modify the circuit and use. Instead of using dew sensor replace it with LDR. output you can use an opto-coupled triac to control the Street Lighting. If you have any doubt please contact.
sir,i am the student of B Tech 2nd year, I gonna do a mini project of topic ‘Automatic Street Light Switching Device’. I am using an integrated circuit ICLM358. sir please design the circuit diagram using this IC.
sir, thanks for the circuit, I have made a prototype of street light circuit for our project, and guess what? I got the highest grade in our class. thank you very much sir!
sir its so interesting……………..think you………..
Reply to Michael Garoso
sure
sir?can I use 220v AC source, instead of 230v? thank you…
Can I model the street lighting circuit using pspice?
How can we get a 9v DC in street lighting system which is totally working in ac supply. Is there any method to generate 9v Dc from universal ac mains 110-230 Vac without any resistor losses and heating issues. kindly help me.
Author: The value of relay is added in the notes.thanks for pointing out.
sir please tell me which relay i can use