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Circuits
Overachieving and under-appreciated, circuits are the foundation that our technological society is built on. Now's your chance to find out not only how they work, but why. Questions regarding the physics behind voltage, resistance, capacitance, inductance, transistors, LEDs, switches, and power supplies; and how they're used to create analog and digital circuits, should be directed here.
1,646 Questions
What is the effect of changing the numbers of batteries in a circuit?
Before we can attempt an answer to that question, we'll need to agree on the
meaning of the fuzzy, slippery phrase "amount of electricity". I'm going to interpret
that phrase to mean the current through the circuit.
If the batteries are connected in series, then more batteries produce more current
through the circuit.
If the batteries are connected in parallel, then the number of them has no effect
on the magnitude of current through the circuit. But whatever the current is, more
batteries will cause it to flow in the circuit for a longer time, before they run down.
What does the voltage rating of a capacitor mean?
The voltage rating of a capacitor is the maximum amount of voltage that a capacitor can hold. Going above this rating can damage and destroy the capacitor.
AnswerExceeding a capacitor's voltage rating can cause its dielectric to break down. A capacitor's voltage rating is generally expressed as a d.c. voltage so, if it is to be used with an a.c. system, it's necessary to know the peak value of the a.c. voltage, which is determined by dividing the a.c. (rms) voltage by 0.707.
Circuit Switching
Circuit switching is used for ordinary non-digital telephone systems. It allows communications equipment and circuits to be shared among users. Each user has sole access to a circuit (functionally equivalent to a pair of copper wires) during network use.
A circuit switching network is the one that establishes a dedicated circuit or channel between nodes and terminals before the user may communicate. Each circuit that is dedicated cannot be used by other callers until the circuit is released and a new connection is set up. Even if no actual communication is taking place in a dedicated circuit's channel, that channel still remains unavailable to other users. Any other channel that is available remains unconnected (set to "idle") until a new call appears.
Why is the main switch connected in series together with the rest of the circuits in the house?
It is connected so that it can disconnect the entire power grid in the house with one switch. This switch is usually integrated into a circuit breaker. No matter how one looks at it, this switch must be made to withstand (and be able to switch) great currents (in excess of 16A) at relatively high voltages (120V/230V).
Special care must be taken during the design phase, as the switch will most likely have to suffer severe arcing as well as heating, during normal operation.
What is harmonics in electrical circuits?
By simple definition, harmonics are any "non-linear" current or voltage in an electrical distribution system. An electrical harmonic shouldn't be thought of as an acoustic or vibrational harmonic, but simply as any electrical device that draws current un-proportionally to voltage. Harmonics are commonly produced by devices that rectify AC Voltages into a DC Voltages. Common harmonic producing devices are VFDs, lighting, and computers.
When do harmonics cause problems?Current HarmonicsThese important bridge rectifier circuits produce current harmonics. Current harmonics do have an affect on the electrical equipment supplying harmonic current to the device (transformers, conductors). Current harmonics can cause issues with distribution equipment which has to handle the current from the utility transformer all the way down to the device, but generally don't affect other equipment connected to the electrical system. Harmonic currents can cause excessive heating to transformers. For electrical systems feeding single phase loads the third harmonic has gained attention in design consideration and transformer selection for causing the neutral conductor to draw excessive current.
Voltage Harmonics
Voltage harmonics can effect sensitive equipment throughout your facility. Voltage harmonics arise when current harmonics are able to create sags in the voltage supply. When any device draws current it creates a voltage dip which is required for current to flow. This voltage dip is visible with larger loads when turning on a hair dryer or a table saw and seeing the lights dim down. The amount of sag depends on many factors like transformer impedance wire size. Current harmonics create voltage harmonics, but the magnitude of the voltage harmonics depends on the "stiffness" of your electrical distribution's "system impedance."
An example to help understand current distortion verse voltage distortion is the common CFL light bulb. This low cost light bulb may have a 75% current THD (total harmonic distortion). This means that 75% of the current drawn by the bulb is considered "harmonic current". These light bulbs usually do not affect other devices in your home because even though the current drawn by the bridge circuit is rich in harmonic current, it creates very little sag in your home's voltage supply, and if you had a voltage analyzer attached you would probably see a voltage THD of well less than 1 percent.
Avoiding Harmonic Issues
If possible it is best to select equipment with a low current THD, and the result would be reduced voltage THD. If you are not able to purchase equipment with a low current THD there may be options available to you like adding line chokes or isolations transformers to reduce the harmonic currents. If you are unable to reduce current distortions and are having issues with the affects of voltage distortion there are options, such as tuned capacitor to supply harmonic current, or possibly redesigning your systems distribution to reduce system impedance.
Solutions for Mitigating HarmonicsThere are many solutions to alleviating the affects of harmonics, below are some commonly applied solutions.
Reduce Current Harmonics
Add line chokes to harmonic producing equipment.
Add isolation transformer to harmonic producing equipment.
Use 12-pulse or 18-pulse rectifier circuits, instead of 6-pulse.
Reduce Voltage Harmonics
Add tuned capacitor banks to supply harmonic current, or change transformer size/impedance.
Other
Isolate sensitive loads instead of mitigating harmonics.
What wire size is needed for 15 volt circuit?
The wire size depends on how much current it will conduct.
What type of a circuit do flashlights use?
A flashlight is a series circuit. The batteries positive end connects to the flashlights switch. The switch connects to the center pin of the light bulb. The bulb filament is connected to the center pin of the bulb and the outer metal shell of the bulb socket. The shell of the bulb socket is connected to the metal flashlight's body which returns to the negative end of the battery. Turn on the switch and you have light.
A latching circuit is a circuit with two stable states, which one can think of as 1 and 0, thereby being able to store one bit of information. In circuit diagrams, these are represented by cross-coupled NOR or NAND logic gates.
T1 line
Advantages of semiconductor diode over vacuum tubes?
A semiconductor diode has these advantages over a vacuum tube:
- smaller
- cheaper
- runs cooler
- much more rugged
- very long life
- no heater, so needs no power supply to work
- less electrically noisy
- can be made part of an I.C.
When V(gs) is less than V(t). The minimum external energy which is provided to V(gs) in order to cross v(t) is know as clip voltage.
Total opposition to current flow in an AC circuit?
I oppose alternating current. Direct is the only way for me. That is 1 in opposition.
Calculate the voltage of required to push eleven amperes through a 20-ohm resistance?
U = RxI so 11x20=220 volts
Standard TTL (which stands for Transistor-Transistor Logic) circuits operate on a 5V power supply. The typical level for a logical "0" is between 0V and 0.8V, and the typical level for a logal "1" is somewhere between 2.2V and 5V. Typically, a value little lower than Vcc (power source voltage) is used; in case of a 5V supply, this is usually around 4.5V, but TTL devices are built to withstand full Vcc as input, just in case.
What happen ohmmeter hook up to a live circuit?
Depending on the voltage, make sure to be safe, but I don't think that it is too bad, although it does depend on the circuit
Advantages series and parallel connection?
If a switch is added, all of the bulbs/lights/motors can be turned on and off at the same time, instead of needing several switches.
Also, if a bulb is dead, you can't tell what bulb is dead because they are all connected.
No. This practice is a violation of Article 210.19 (A) of the NEC. "Conductors of branch circuits supplying more than one receptacle for cord-and-plug-connected portable loads shall have an ampacity of not less than the rating of the branch circuit."
What provides energy to circuit?
One possibility for what affects the voltage,
is how many light bulbs, motors etc you have in the circuit causing the energy ( voltage ) to be shared.
What board holds microchips or integrated circuits and the circuitry that connects these chips?
The board that holds microchips and electronic circuity is called a printed circuit board (PCB).
More information: http://en.wikipedia.org/wiki/Printed_circuit_board
I do not agree with the above answer... i believe the correct answer you are looking for is an "adapter card".
What is vaccume circuit breaker?
In VCB, The two contacts are present in a vaccum, When there is a fault these contacts are forced to open resulting arch ,as all we know arch does not flow through Vaccum so it extinguishes thus vcb seperates two circuits.
Can you change a 470 microfarad 16 volts capacitor with a 470 microfarad 35 volts?
C=Q/V12 where Q/ V12 is the Charge per Potential Difference between the plates of the capacitor. If you solve for Q, you see that the charge is proportional to this potential difference. You are likely to surpass your load requirements by increasing the charge/discharge amplitude with the 35 volt cap. In other words, your cap will charge up to 35 volts and then discharge that 35 volts onto your load that was set at resonance to operate with 16 volts discharging. Any separation of circuits using this cap would probably fry something on one side or the other over time. Hope this helps.
