Light Alarming System

[The Dandelion]

Hi guys..

I am new to this site, I am an electronics student, my instructor showed me this forums, so I can solve my electronics problems here.

I just need a help

I am planning to make a light alarming device that sense the intensity of light(using solar cells) of indoor places and then gives a warning signal when light intensity exceeds certain limits that can be adjusted by the consumers...Gimme examples of important components that I should use to design this system.

 

[Dr.EM]

Amplifier, comparator, potentiometer?

 

[JimB]

Hi guys..
...Gimme examples of important components that I should use to design this system.

Well, lets see...
You will need some solar cells, some resistors, a few capacitors, one or two integrated circuits and a few transistors.
A light emitting diode or two may be useful, you may also be able to use a buzzer of some kind to give an audible alarm.
A power supply of some kind, maybe a battery or a wall wart.
Dont forget the wire, you will need wire to connect things together.

There must be many other things which I have forgotten, but I am sure that others here will chip in and give you valuable suggestions.

JimB

 

[The Dandelion]

JimB

I really thank you, I am feeling much better and more motivated to do it so

There is one guy I know suggests me to use LDRs, but I am still not quite conivenced with this, since LDRs resistance decreases as light intensity increases and might gives reverse results. Is it ok if I build the system without LDRs?

 

[audioguru]

It is easy to make an electronic circuit that reverses the results if you want. A transistor or an opamp will do it.

Are consumers complaining about lights in stores that are too bright? Don't their eyes have an iris that automatically adjusts for light brightness? Some of these new LED traffic lights are pretty darn bright at night when they shine directly into your eyes. Those high intensity lights on cars are also blinding.