Switches, relays and construction of my robot 1/13/11

Today we experimented with switches and relays. In our first experiment we had two switches in series with our LED where both switches has to be in position 1 or in position 2 for the LED to be lit. In the second experiment only one switch was used and the other was replaced by a relay. With the relay we are using today, there will always be a path for our current to flow through one of the LEDs. When the switch is open, the power is flowing through the green LED as shown in the picture. 

The green component is a monetary switch. The black component is our relay.

 I was having a little trouble having the relay stay in the board so I had to hold it in with my finger. The next figure shows the same circuit with the monetary button being depressed to close the relay and change the path of current to flow to the red LED.

In the last circuit for the day, we made an oscillator. We did this by adding a capacitor in parallel with our relay. When this circuit is running and the button is pressed, the LEDs will flash one at a time. Also you can hear the inner workings of the relays switching between contacts. This sound is similar to a buzzing sound. A quick note to remember is that the larger the capacitor the slower the rate at which the relay switches.

The black cylindrical component is our capacitor.

 Here is a couple photos of our completed robot fitted with a front and rear bumper buttons. Also the battery pack up top will be exchanged for a rechargeable battery.