Voltage Dividers Lab

The Voltage Dividers Lab is designed to familiarize engineers with the concept of an electrical system having multiple loads that can be switched on and off. One very basic example of this is an electrical fan with multiple speed settings. The idea is to provide multiple loads across a circuit and in this case use it to control the current going through any individual load.

The picture (courtesy of Nick Moran's Blog)  illustrates the basic concept of the circuit. Imagine a Voltage supply and resistor (resistor box) is connected in series with 3 resistors of the same resistance value in parallel to each other. These resistors would then be either connected or disconnected to modify the current going through any of them. In a real world example, one of these resistors could be replaced with the load and voila; simple way to vary the current across a load!

Here is the data we collected with varying configurations of resistors in parallel;

Config	EQ Resistance (Ohms)	VBUS (Volts)	IBUS (mA)	P Load (calculated Watts)
1 Load	1003	5.68	5.72	0.032
2 Loads	499	5.34	10.76	0.06
3 Loads	334	5	15.25	0.076

Overall the circuit tested in this voltage divider lab is a great way to control currents through a given system without being needlessly complex. The real world applications of this concept are numerous and can be found in countless modern circuits. Quite counter intuitively, the more loads placed in parallel, the less the equivalent resistance and hence the less strain on a battery because it would have to supply less current!