March 9, Voltage Dividers

The purpose of this lab is to design a battery source and a resistor at the beginning of the circuit to make 3 parallel loads work when different switch is on. First we use 3 1k ohm resistor to represent the 3 loads and put them in parallel. Then we calculated that the maxium of Req of three loads is 1000ohm and the minimum is 333ohm. Then we solved for voltage across the battery and the resistance of the resistor at the beginning of the circuit. In the picture, the yellow resistance box is our beginning resistor. we set it up to 55 ohm. then we connect everything through breadboard. We put voltmeter and current meter into the circuit and measure the Req, voltage across the loads and current. We found out because our battery source doesn't have 5.5V, so we used a 6.12V.
1 load: 999ohm            2 loads: 498 ohm                3 loads: 333ohm
V= 5.77V                    V=5.46V                            V=5.18V
I=5.7mA                       I=10.7mA                          I=15.1mA