Introduction to Biasing

This lab consisted of 2 Light Emitting Diodes connected in parallel to each other to a current source. Unfortunately, the LEDs were not rated high enough to be able to withstand the kind of voltage being put out by a 9 V battery (simulated in this case by a power supply) so we had to connect two resistors (one before each LED) to lower the voltage. Here is the basic set-up that follows;

Current enters from the orange wire on the top right corner of the bread board, it is then split among 2 resistors and the resulting currents go through the respective resistors and into the LEDs (using the correct resistors we were able to ensure that the LEDs did not blow) and then back into the power supply through the green (right) and yellow wires. The other orange and green wires on the left were connected to the voltmeter

The red LED was rated to take 2V while the yellow LED was rated to take 5V. Unfortunately, the power supply puts out 9V so we had to put a resistor before each LED. Using Ohm's Law we were able to calculate the equivalent resistances of the LEDs which gave us the ratio of the current going through each. After knowing the currents going through each branch and the maximum voltage of the LEDs we were able to calculate the values of the resistors which were 175.8 Ohms and 350 Ohms for 1 and 2 respectively