Electronics Engineering

When two resistors are in series, you add the elements together. When two elements are in parallel you multiply them and divide that by the sum. ie: parallel elements 7 ohms and 8 ohms (8*7)/(8+7).

If there are more than 2 in parallel however, just fill in this:

1/Req=1/R1 + 1/R2 + 1/RN

Req is the final answer of the equivalent resistance.
Rn means you keep adding the reciprocal of the other resistors in parallel.

No doubt either of those approaches would certainly work.

Personally, since I don't see well enough to wire a CMOS board, and I don't know

how to program a PIC, I would probably go to the big 'home improvement' store

and buy a couple of timers. One of them has to be the kind with two AC outlets ...

one normally on and one normally off.

-- If the interval you want is less than 24 hours, then all you need is a simple

kitchen timer.

If it's more than 24 hours, then you can do it like this:

-- Plug the 'double-throw' timer into the wall. Plug an ordinary kitchen timer

into its normally-off outlet.

-- Now here comes the part where you need to understand electronics and

know how to use solder and black tape: Attach two AC line cords in parallel

to whatever supply you use to power your solenoid.

-- Plug one line cord into the normally-on outlet of the first timer, and the other

line cord into the kitchen timer.

-- Set both timers so that their sum adds up to the interval you want.

While the double-throw timer is running, it powers the solenoid power supply,

and the kitchen timer is unpowered.

When the first timer expires, its two outlets flip. The kitchen timer starts running,

and it powers the solenoid supply until it too expires.

This rig can run any interval from very short to almost 48 hours.

Sometimes I'm so clever I make myself sick. Especially in the abstract.

I'll leave you to work out the kinks and the bugs and actually make it work.

That should be no problem for a guy who can work with CMOS ICs and PICs.

Wiring a T101 timer is easy. All you have to do is color code the wiring into the input sections.

The conventional earth is the use of a copper rod and plate driven into the earth.
In dry areas this may be not sufficient to make a good earth and chemical systems are available. Chemical earths use a more resistant material to copper in the form of a tube packed with chemicals.
These earths are more for the use of lightning conduction rather than electrical safety earth.
Very popular in India.

voltage divider biasing

Measure AC voltage with multimeter. It is easiest way to check how big ripple is.

There is no way to 'calculate' value.

Film capacitors cannot be replaced with ceramic or mica capacitors if used for analog signal processing. However, mica capacitors can be replaced with ceramic capacitors in general.

'Doping' is the word used in sport when athletes use prohibited substances or methods to unfairly improve their sporting performance.

There are many different errors that can happen in a medical ventilator. The medical ventilator could just freeze up and stop working for example.

Assuming that you are familiar with p-type

and n-type doped semiconductor materials,

we will consider silicon, in simple terms.

At the p-n junction area, electrons can more

easily pass from the n side to the p side.

This is due to the availibility of surplus electrons

in the crystal lattice structure of the n-type silicon.

Likewise a shortage of electrons in the crystal

lattice structure of the p-type, makes it a willing

acceptor of the electrons from the n-type at

the other side of the barrier.

This transfer through the junction requires a

specific force, in electrical terms what we call

voltage. For silicon 0.6 to 0.7 volts gets full and

safe current flow through the junction.

Less than about 0.6 V the current will be much less.

If the voltage polarity bias of the junction, is such

that the pressure is now trying to force electrons

from p to n, there will be only a tiny leakage current.

The result can be seen to be that a diode is a

one way valve for electrons. They can go

from n to p but not p to n.

Note that the arrow on the diode symbol is

pointing in the opposite direction to the

direction of electron movement. This symbol

was designed in the conventional current

only era, before we found out that current is

actually the movement of electrons.

YES 455 kc if i remember correctly

Everyone is clear on what a filter is, but there exists a lot of confusion over what is the difference between a duplexer and a diplexer. As you might expect, there are a lot of opinions - even between manufacturers. Traditionally, duplex communications implies the ability to transmit (Tx) and receive (Rx) on the same channel simultaneously. doing so requires a means of separating the transmit and receive paths in a manner rendering them independent of each other, i.e., isolation. Thus, a duplexer

is used. One method is to use a circulator for routing signals from the transmitter to the antenna while routing singles from the antenna to the receiver. If the Tx and Rx operate at different frequencies, the job can be accomplished by a set of filters with a common feed point. A diplexer

is usually thought of as a set of filters, again with a common feed point, that is used to combine or split signals travelling to or from an antenna, respectively, while providing isolation between the two independent paths. If more than two independent paths are required, the name for both usually changes to a common term: multiplexer.

It is the Electrical Engineers that do come up with all the networking standards like IEEE 802.11 and Ethernet. A EE with the CCNA automatically is able to have the title of Network Engineer.

SCADA stands for Supervisory Control And Data Acquisition. It generally refers to an industrial control system: a computer system monitoring and controlling a process,A Human-Machine Interface or HMI is the apparatus which presents process data to a human operator, and through this, the human operator, monitors and controls the process.

Well intrinsic semiconductor is semiconductor crystal with no impurities in it. In intrinsic semiconductor the electrons in valence band(valence electrons) gain energy(due to thermal enegry) and break free into conduction band(means it become free electrons). As this electron breaks free, a vacancy is created in place of it. It is called as a hole. This hole has a positive charge. So current in semiconductor is due to flow of this free electrons and holes. But this current is very small in magnitude. The difference between free electrons and valenece electrons is that valence electrons are often bonded to other atoms in crystal. But free electrons can freely move throughout the crystal.

Generally, the valence electrons in the atoms of the molecules in plastic hang out in Fermi energy levels lower than the energy bands that an electron would have to occupy to support conduction. The electrons are bound to parent atoms, and they also may have some mobility within the molecular matrix of the material, but any energy applied (like voltage) doesn't really get the attention of these electrons. They chill in energy levels too low to be jerked up into the conduction band with any fair amount of applied voltage. And if the electrons are not in or cannot easily reach the conduction band (an energy level high enough to support current flow), the material won't support conduction and is said to be a bad conductor.

it depends on the type of the circuit you are analyzing..it could be a voltage divider, emitter follower, be specific on what type of circuit and maybe i can help you aobut this question.

Complex frequency is utilized in electric circuits in order to simplify the math, essentially. It is very similar to the use of phasors, except complex frequency can cover all types of inputs, not just sinusoids.

A series circuit is where there is only one path for the current. As a result, and as a direct consequence of Kirchoff's current law, the current at every point in a series circuit is the same. The two bulbs have the same current flowing through them.

The fourier series of a sine wave is 100% fundamental, 0% any harmonics.

the reason metals are good conductors is because in their subatomic structure electrons float as if in a sea, also called a sea of electrons that is why you can magnetize most metals and they conduct electricity.

Leading and lagging currents are not so much "currents" as they are "situations" or "conditions" in an electrical circuit. Reactive characteristics, if there are any, will not let voltage and current be in phase in a circuit. (Unless they are equal, and this will be true at only one frequency.) In some circuits, current leads voltage (or voltage lags current), and in other circuits, current lags voltage (voltage leads current), depending on the circuit and also on the frequency of the applied signal. In a capacitor, current leads voltage, and in an inductor, current lags voltage. This carries over to circuits that exhibit primarily capacitive or inductive characteristics. Additionally, reactance varies with frequency. As a given circuit with inductance and capacitance is evaluated, at some frequencies, it will appear capacitive, and current will lead voltage. At other frequencies, the circuit will appear inductive, and current will lag voltage. Only at a frequency where the reactances are equal will the current and voltage be in phase. The ideas here are best reviewed after achieving an understanding of the nature of inductance and capacitance, the associated reactances, and the way frequency affects these characteristics.