Electrics Flashcards
Ohms law
V = I X R
Formulae for Voltage drop in a series circuit with resistors
Vout/Vin = R2/R1+r2
Formulae for the resistance needed for a desired voltage drop
(Desired voltage/Vin-Vout) x R1
Described the function of a Wheatstone Bridge circuit
Two parallel circuits with 2 resistors each.
Voltage drop from between each resistor
If these voltage drops were connected through a galvanometer.
The Resistors on each parallel circuit need to an equal ratio of resistance.
If one of these resistors were replaced with a transducer and the other resistance are known then the galvanometer can be used to identify the resistance created by the transducer.
Described the function of a capacitor
Two plates separated by a dielectric material
Current flows through the circuit. The proximal plate becomes increasingly charged (as it stores the electrons).
The distal plate becomes increasingly oppositely charged.
The capacity reaches the maximal voltage of the circuit (rate of change in voltage decreases). The current through the circuit decreases proportionately to the voltage increase.
Formulae for voltage over a capacitor
V= Intergral I/2pifC
Unit of capacitance
farad
inductor function
as current flows through coiled wire electrical energy is converted into electromagnetic energy
this opposes the current of the circuit.
When the power is removed the magnetic energy is reconverted into electrical energy.
Formulae for voltage drop over a inductor
v = 2pifL x dI/dt
unit of inductance
henrys
Describe the effects of frequency and output of an RC circuit
High frequency causes a low voltage output.
Acts as a high frequency blocker and a low frequency pass circuit.
Vout is the integral of V in - electrical integrator
Describe the effects of frequency and output of an CR circuit
If frequency if large then Vout is low.
Acts and a low frequency blocker and a high pass filter.
Vout is the differentiation of Vin - therefore is an electrical differentiator
Describe the function of a tuned circuit
Contains the capacitor, inducer and resistor.
Reactants is inversely proportional to to a capacity and directly proportion to an inductor
The point where inductor reactants meets capacitor reactance is where the resonant frequency of the circuit is. This point is where the Vout/Vin is at the maximum.
