feedback and control system

[071390]

we have a project in this subject. our group's idea is an LDR sensor wherein when there is light, the curtain will go up and when there is no light, the curtain will go up. we are planning to use a relay and a motor (dynamo) to control the raising of the curtain. is it possible? any suggestions how we can do our project. we just need a prototype, that's why we'll just be using dynamo. please help us. thanks!

 

[Reloadron]

Yes, it is possible. You have your curtain going up but never down? Your curtain will need stops. If the curtain gets an up command you want it to go up but it will need a stop, likewise for down.

A simple LDR configured into a comparator circuit would give the raise/lower commands to the curtain based on light striking the LDR. Read about comparators on this link and scroll down to the part that shows a few simple LDR circuits. Also note the section on hysteresis. That should get you started.

Ron

 

[Boncuk]

Hi,

if you mean using a bicycle dynamo as a motor you'll have to use a starter circuit for the dynamo. It behaves like a synchronous AC-motor.

Better use a small DC-motor which can be reversed by reversing supply voltage.

Boncuk