Electronics: Currents and Circuits Flashcards
What are the two modes that current can travel in?
Alternating and Direct Current
Most electronics are powered by…
DC
What kind of current is provided by batteries?
DC
Differences between AC and DC
DC only travels in one direction, negative to possitive. Flow and polarity is constant.
AC alternates its flow direction, polarity.
What kind of current do most households receive?
AC
Why are households provided with AC?
AC is easier to transmit across greater distances at large vlotages, without burning the cables.
What kind of current is used by houses that are off the grid?
DC, as they are the power generated are stored in DC batteries
What sort of things are commonly associated with DC
Batteries
Electronics
Telecomunications
Off the grid houses
What are the characterestics on a wavform?
Amplitude peak amplitude cycle period frequency
Amplitude
The measurement of any point of the wave that is either above or below the mean line
Peak Amplitude
the point of the wave that is farthest from the mean line, possitive or negative.
Cycle
One complete evolution of a wave’s shape
Period
The amount of time it takes to complete on cycle. Symbol is T. Measured in seconds and milliseconds
Frequency
The number of complete cycles in a given amount of time. Symbol is f, and is measured in Herz(Hz)
One Hz is equal to…
One cycle per second.
What is the frequency of AC delivered to households in America?
60Hz
What is the relationship between frequency and period?
f = 1/T
T = 1/f
What device can be used to see or visualize waveforms?
oscilloscope
What is an Altenator?
An AC generator
What are the two parts of a generator
The rotor and stator
Different kinds of waveforms
Sine, Square, Sawtooth, and Triangle
Which waveforms are the most common in electronics
Sine and square
Which waveforms are used in cathode ray tubes and vocal harmonics
Sawtooth
What is phase?
The relationship between two waves.
When are waves in phase?
When they overlap
What is phase shift?
If two waves are of the same frequency and voltage but don’t overlap, they have a phase shift. The first wave is called the leading wave, the next wave is the lagging wave.
What happens with a 180 degree phase shift?
The two waves cancel eachother out.
Why is peak possitive and negative voltage important?
Because it allows us to unsure that any circuits we design can tolerate the peak voltages
What is peak voltage?
Voltage measured at the highest or lowest point of the wave. Abreviated P or PK
What is Peak to Peak voltage?
The combined amplitude from peak possitive to peak negative. Abreviated PP
How to caluculate the average voltage of an ac current?
Mulitply the peak voltage with 0.636
How to calculate the DC equivalent or root-mean-square/effective voltage?
Peak Voltage X 0,707
A device that converts AC to DC
Rectifier
A device that converts DC to AC
Inverter
Why is it important for a circuit to offer resitance resulting a voltage drop?
Heat will be produced as a result of friction along the circuit. The heat can damage the circuit and the chemicals in the battery, causing a short circuit
What is an overloaded circuit?
A circuit to which too much power is provided, leading to overheating and damage to the components, or even fire or and explotion
What are two types of protective devices used to prevent a short circuit
Fuses and circuit breakers
What are the three different kinds of circuits
Series, Parallel, and Series-Parallel
Difference between a Series and Parallel circuit?
A series circuit moves the current through the components sequentially. A parallel circuit allows the current to flow down two or more paths simultaneously to do more than one operation.
