Logic probe construction.

This blog is of the LED logic probe made in pratical class.

We were given our LED logic probe in bits. I soldered the positive leg of the green LED (longest leg out the two) on to resistor, I put heat shrink tubing on and soldered all three bits together in series then slid the shrink tubing towards the LED coving all exposed wire and heated it. Now when connected to power, the current will travel through red wire acting as the conductor. As the electrical current travels it flows through resistor which then slows down the electrical current flow to the LED. I repeated the same process with the black wire, resistor and red LED.  If resistor was not present, there would be a greater voltage current for the LED to consume and would blow.

I then prepared the brass rod by shapening one end and finding the middle of the rod, I skuffed around and tinited with solder so that when LEDs are on, it would get a good earth. Next was to heat shrink the rod because it would be live and heat up when the current would flow though it.

Next was to put both LEDs onto the solder or tinned area and wrap negative leg (shorter one of the two) around it and solder LEDs to brass rod. Then using  glue gun, glued in the middle of LEDs to add stability. In doing this, when electricty is switched on, I would have made a series circuit. Both LEDs will both go, showing current is flowing through circuit. When it contacts with the positve, the green LED will go out showing theres a high resistance making it a positve connection which will then light the red LED brighter because current is not flowing through green LED. When probe is touching negative, the red LED will go out and green LED will glow brighter cause there is no current flowing through red LED.