Automatic Hand Dryer Help

Hello
I need help in analyzing this circuit. I would be grateful if anyone could give a clear cut explanation on the functioning of the circuit and the role of each component present in it.
This is for my mini project. The circuit diagram has been attached.
Thank you

Since this is your mini project how do you think the circuit works. You share your thoughts on circuit operation and someone here will be happy to work along with you. If I or someone else explains in detail how the circuit works you won't learn much.

Ron

Okay
I know how it works. But I want to know what each specific component is there for. For eg. a particular resistor connected at a certain spot or a capacitor. I know the general working.

It consists of three parts
1. a proximity sensor
2. a timer to time the ON OFF period of the fan
3. a heating fan


The sensor detects the presence of your hand with IR LEDs and photo diodes. Then something happens and the timer IC turns on the drying fan depending on the RC timing resistor and capacitor. But an explanation like this won't get me any marks.
This is where I need help.

Thank you

Vinod

Look at the datasheet for the 555 and the monostable and one-shot configurations.

Remember that a push button could replace the IR transistor, but it would not be touchless then.

The sensor is usually one piece with the emitter and reciever in one part. Look up "reflective object sensor".

vamster said:

But an explanation like this won't get me any marks.

Click to expand...

So this is schoolwork and the way it works is you present your thoughts and explanation of how it works and we work with you but you put forth the initial effort to learn. So if I explain in detail how it works and you parrot that to a teacher who gets the grade, you or me?

Ron

This old time learned something tonight. I never heard of a reflective object sensor. I read the data sheet and understood it. Just interesting reading something new.

Thank you for your help