Electrical Engineering

To control linear actuator by PID controller, use the data from the feedback device. Use the potentiometer to adjust the output until it reaches the target value.

In general, a DCS or PLC, handles numerous discrete I/Os. One common I/O module (board) is used to supply 8, 16 or more points. Discrete output circuits from a DCS typically use low power level signals (transistors, micro relays) which cannot be sent directly to the field devices such as electromagnetic valves or motor control circuits. That is why interposing relays are often necessary.

These relays play an important role by amplifying the current capacity of the contact signal of the I/O module allowing larger current flow. In addition, discrete input circuits normally can handle only dry contacts or wet contacts of low voltage, which also require interposing relays.

For example, let's say the relay of a PLC can only accommodate 0.5A at 220 VAC, but the solenoid which is to be connected to the relay requires 1.2A at 220 VAC. In this case, an interposing relay with contacts rated for operation at 1.2A at 220 VAC would be used as an interposing relay "between" the PLC relay and the solenoid. The coil of the interposing relay should require less voltage and current than the driving relay is rated for, and the contacts of the interposing relay must be rated to handle the requirements of the load (solenoid, light, contactor, motor, etc.).

You compare the btu input with the btu output. Divide the input into the output and that will give you the efficiency. With multiple extraction you will have to add all the uses.

For example 100 million btuh input, with all sources of output having 82 million btuh-

divide 100 into 82, for .82, or 82% efficiency.

Yes, you can purchase a circuit breaker just as you can purchase a wall switch. Big box home stores and hardware stores carry circuit breakers. You should know that they can be a bit expensive, and they are not returnable. Additionally, there are several different types of breaker, and if you have an older electrical panel, you might have to do a bit of calling around to locate a breaker that is made for that setup.

The last thing you need to know is that experimenting with electricity by tinkering with a home electrical distribution system can be fatal. Electric shock can kill the careless or less-than-knowledgeable do it yourselfer. Or an electrical fire can damage the home, and endanger anyone home at the time. Damage to equipment that is incorrectly wired is possible, but that pales compared to the other two hazards.

Replacing a breaker is not extremely difficult, but exposes the worker to hazards that must be managed. Opening the mains breakers to completely de-energize the panel busses is the smartest route. Naturally an exact replacement will have to be chosen, particularly as regards the trip rating. And if you're adding a breaker to a panel to accommodate a new circuit, you'll have to have done the math to insure that the panel is rated for the additional circuit. That's in addition to insuring all that the other wiring meets code and is done in a workmanlike manner.

Shortcuts or "amateur" work on electrical systems cause fires and can kill people. No judgment is passed, but the cautions cannot be overstated. A professional consultation is the best idea, and "experimentation" is discouraged.

Interestingly enough, the mechanism of superconductivity is not completely understood. Since the discovery of this phenomenon by Heike Kamerlingh Onnes in 1911, we've still to explain it away. When a superconductive material is cooled below the superconducting transition temperature for that material, its resistance disappears. The material then becomes superconductive. Why? We have some ideas, so let's look at them.

Some strides have been made in an attempt to explain the nature of superconductivity, but we're still not there. Superconductors can "lock out" magnetic fields, and that should be considered. We see the idea of thermodynamic modeling used along with the application of ideas concerning superfluids and condensed matter. It is thought that electrons might form pairs to become boson-like. But the topic is still open and investigators still wonder what's going on.

Use the link below to begin to understand what we do know and what is suggested. From there an investigator might be able to make the leap in understanding to actually explain what happens in superconductive materials. It isn't a certainty, but there may be a Nobel Prize within reach of the individual or individuals who explain away this now nearly 100-year old phenomenon!

An motor can be connected to the side of a 55 gallon drum filled with water and run that way. Or you can purchase "ear muffs" at a marina. They attach to a garden hose. You put the muffs around the intake ports above the propeller, turn on the garden hose and wait to see if water comes out the exhaust port. If it does, you know you have the muffs in the right place. Then turn on your engine. Start it in neutral! If you put it in forward or reverse the prop will spin. Make sure nothing or no one is around the prop.

show how to test igbt and mosfet in an easy way

feeder pillars are used for distribution of electrical supply to customer in which having a such arrangement that the Incomer with Protection (MCB, SFU,MCCB) from this protection the O/G is connected to the Bus bar and from bus bar the O/G are provided to customer,

Without a bypass capacitor it is just equal to Rc

Yes, additional resistors affect current in a series circuit by increasing the total resistance, which decreases the total current.

in order to avoid electrolysis

No. You cannot create a transistor by connecting two diodes together. There is an interaction between the junctions of a transistor, said interaction being not possible when two diodes are connected together.

A space heater.

Voltage drop

A transformer will convert the power to a different voltage, higher or lower depending on the requirement, while wasting very little of the power.

negative polarity is achieved by grounding the positive terminal of power supply system and the battery bank. This is done to prevent electolysis depositions.

Counter-current flow is more efficient then parallel flow. Shahzad, MUET Chemical Engineer

people who have powers

I'm sure this isn't what you want to hear, but you probably need to ask an electrician familiar with your service and what you want to connect.

As a general answer, you can connect a 240v line to line resistive load like an electric water heater to any 240v source. If you also need the 240v to have 120v line to neutral, like a 240v electric stove that contains a 120v clock and oven light, then its possible if the 3 phase power is connected in a "high delta" configuration, and you connect to the correct leads. If you have a high delta service and want to ignore the 3-phase power service and wire most or all of the loads in the building as a single phase load, the utility may have to be consulted.

The neutral wire should be the same size as your conducters

1500v

From ESD Association ESD Handbook ESD TR20.20 section 5.3.2.1:

"When people are charged with static electricity, they can release stored energy to conductive objects such as doorknobs and electronic circuits. This transfer of energy is called an electrostatic discharge. Sometimes the electrostatic discharge causes visible sparks, but more often, it is both unseen and unfelt. Electrostatic discharges can damage ESD sensitive components used in modern electronics.

Static electricity is a natural phenomenon that occurs in all climates and at all levels of relative humidity year round. Most people cannot feel an electrostatic discharge unless the static voltage is greater than 2000 volts. However, some electronic circuitry can be damaged by ESD that is less than 2000 volts. The damage can be done without people having any sensation of the ESD event.

When a wrist strap is worn properly and connected to ground, the person wearing it will stay near ground potential."

If you got a microphone that converts soft acoustic waves to audio voltage, the low output must be amplified. For that purpose it is good to have an amplifier with high voltage gain. The same is needed for the output of your CD player before it goes to the power amp.

Scroll down to related links and look at "Amplification".

Many amplifiers do not need high voltage gain. The final output stage of a good power amplifier usually has high current gain but very low voltage gain. Amplifiers are also used as mixers and filters where there is no voltage gain.