Dependent Sources and MOSFETs & Resistors and Ohms Law

Fundamental Theorem of Topology: b = L + N -1
b: number of branches
L: number of loops
N: number of nodes

Dependent Sources and MOSFETs

Circuit Graph

Setup

By applying different gate voltage, the drain current goes from 0 to a steady value. 

According to the table and the graph, the threshold voltage for ZVN2110 MOSFET is 1.55V. The maximum current is about 44mA. Between the threshold voltage and the voltage of maximum current, the graph is straight. The rate of change g is about 120mA/V, which is also the slope of the straight part of the graph.

Summary: The MOSFET works as a Voltage Controlled Current Source. By applying different gate voltage, a specific drain current can be delivered. It can also be used for a trigger since it does not deliver any current when the voltage is below the threshold.

Resistors and Ohms Law

This lab measures the resistance of an unknown resistor by applying different voltages. Ohm's Law is verified by the relation between voltage and current.

Circuit Graph

Setup

We applied 6 different voltages and measured both voltage and current.

The graph shows that current is linearly related to voltage. It verifies the Ohm's Law. The slope of the graph is the reciprocal of resistance. there is a relatively law percent error of -3.18%. The equation of the best fit curve is y = 0.001x.

Summary: Ohm's Law shows that current is linearly related to voltage and the ratio is the reciprocal of resistance. This is the law that connects the three basic elements of circuit, voltage, current and resistance together.