Need help with circuits and photocell

[Ether]

Originally Posted by bhandel76

What I want to happen is, when the light is on the photocell sensor, the motor will come on and spin left (counter clockwise) "x" amount of times, the quit. Then, when it is dark on the photocell sensor, the motor will spin clockwise "x" amount of times and stop.

Your description of the desired behavior is incomplete.

What do you want it to do if the light is removed from the sensor while the motor is spinning CCW? Stop immediately and spin CW? Or finish the CCW spinning and then spin CW? Or ignore any changes that occur while the motor is spinning?

Do you want the circuitry to require a persistence of the sensor state before action is taken? In other words, if the light on the sensor is removed for 1 millisecond do you want the motor to start spinning CW? Or do you want the circuit to ignore momentary changes like that?

What is the operating voltage you will be providing to the motor, and what is the current draw?

Are you going to make one of these, or 10 million?

How big can the controlling device be? Is there a size or weight limit? Can it be supplied with 120vAC power?

[Al Skierkiewicz]

b,
We approach these problems with a little more precision. So we need to know the amount of precision you need. A simple circuit can be developed that will spin the motor in one direction when lit and then spin in the other direction when dark. However, the length of time it will spin (or the number of rotations that it will make) will not be controlled and therefore will not be repeatable from one trigger to the next. The size (output power) of the motor also will determine the complexity of the circuit to some extent. If you are merely turning a small hobby motor like a slot car might have, then a simple circuit may be made using a dual 555 timer, some resistors and capacitors, and two miniature relays in addition to the photocells you have shown. Again, this circuit would very likely vary widely in the action of the motor.

[DavisC]

Hey,
Yea I second (or should i say third) what the others have said. While only a10th grader (although the team captain/programmer/electronics) I am familiar with this, in terms of FRC and programming while no expierence with circut boards.

-From a programmable board (microcontroller- "is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals." http://en.wikipedia.org/wiki/Microcontroller) perserpective, this would be relatively simple asumming you know some basic programming. This method could be accomplished using a cRIO or as I've been looking into recently a Arduino board.

-Now the part that I am not familiar with: Using only a circut board (breadboard). But what I do no is that in my school's physics class they commonly have to make something that will run off a timer using just circuts.

Hope this defines your 2 most basic options which each branch off on their own.