Logic Probe

On friday we were to make a logic probe using the practical book as a guide and help from prem and sefa., Equipment we used was :

• Brass rod
• Red and Green LED
• Black and Red wire 2 meters long
• 2 resistors 1k ohm
• Red and Black aligator clip
• Soldering iron
• 12v power supply
• 100mm plastic tube 7mm ld

We connected te red clip to positive and black to negative.Both red and green LED's lighted up. This shows us that the component is working and there is good connections. When we touched the brass probe end to the positive battery terminal the green LED goes out, this is because when you put positive to positive there is short circuit, so there is no green LED light. When we touched the probe to the earth battery terminal the red LED goes out and the green got brighter, this is because there is a short circuit in the green LED so there is 12v going to red LED so therefore it gets brighter.