# Electrical Circuit Help - Spinning Motor + Battery + Light

Joined Jun 8, 2010
2
I am making an electrical circuit for my Science summative. I want to make a game, detailed below.

I will have a spinning motor with either a spinner on it or a piece of metal. I have a 6V battery that will be connected to a light switch, which will be connected to the motor so that the spinner starts when I hit the switch.

I will also use the 6V battery and attach it to a small green Christmas light. The other end of the Christmas light will be loose near the spinner.

Now this is the part I need help with. How can I make it so that when a certain blade of the spinner touches the loose wire from the light, the light will shine?

I am trying to make a game where you have to try and turn off the switch so that when the blade/spinner comes to a stop, the green light is on.

Please give me any alternate ideas, or tell me how to make this one work.

#### coldpenguin

Joined Apr 18, 2010
165
It would probably be easier to not have the wire touch the end of the spinner, but to have the end of the spinner fall within a 'zone'.
Then you could have a commutator/brush on the spindle of the motor, which could be used to detect that the spinner is in the correct position.

#### Markd77

Joined Sep 7, 2009
2,806
How about a magnet stuck to the side or underneath of the spinner and a reed switch fixed somewhere near that the Christmas light is connected to.

Joined Jun 8, 2010
2
It would probably be easier to not have the wire touch the end of the spinner, but to have the end of the spinner fall within a 'zone'.
Then you could have a commutator/brush on the spindle of the motor, which could be used to detect that the spinner is in the correct position.

This is a grade 9 summative so I'm not exactly sure what you mean. Can you help me out by telling me what materials I'll need and exactly how to put it together?

Thank you.

#### coldpenguin

Joined Apr 18, 2010
165
Actually, I think that Mark's idea is better. It would be a lot less fiddly, but it might require a counter-balance for the magnet (so that it doesn't wobble the arm).

You would need two parallel circuits.
The first one, goes from the battery, to your switch, to your motor then back to the battery.
The second, goes from the battery, to the reed switch, to the light, then back to the battery.

When a magnet is held near to a reed switch, the switch activates and closes the circuit (so if there is a choice, you need to wire to common, and NO (normally open) on the reed switch).
You then attach the reed switch so that it is held firmly, close to the area where you wish the end of the spinner to be in. On the spinner, you attach the magnet near the switch, and then opposite to that across the pivot you would require something else heavy to balance out the magnet.

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