Pneumatics

All electronic logic functions can be implemented with pneumatic logic devices which simply operate using compressed air and vent into a cabinet (i.e. there are no problems with oil or fluid leaks).

Pneumatic memory has set, reset and output lines like electronic memory. The logic state is remembered by a small valve spool (maybe 20 mm long). A one bit memory may be the size of a matchbox or larger but it also needs ancillary components (other logic, timers, air supply, filter etc.). They are probably not widely used today - most likely in hazardous environments.

47

Inductive load power is reactive, it is given by the formula:

pL(t)=VL(t)IL(t),

in time domain (instant power);

PL(s)=VL,RMS(s)IL,RMS(s),

in Laplace transform domain (RMS denotes root mean square amplitude).

VL is the voltage across the inductor L and IL is its current (current enters in the "+" voltage reference pin, by applying user convention in which absorbed power is positive).

Power is reactive since voltage and current are always in quadrature:

VL(s) = s L IL(s),

in Laplace domain (derived from the time-domain formula vL(t)= L diL(t)/dt).

A real-life inductor will also show an active power term, which arises from parasitic resistance non-ideality; it can be modeled as a resistance DCR in series with the inductor itself:

pACT(t)=DCR IL(t)

<<>>

An inductive load such as an induction motor draws power from the supply with a power factor of less than 1.

Power = voltage x current x power factor.

This happens because the current reaches its peak in the ac cycle after the voltage, so that for a small part of the cycle power flows back into the supply from energy stored in the motor's internal magnetic field. The time-lag is measured in degrees and called the phase difference. 360 degrees denotes one complete cycle.

The power factor is the cosine of the phase difference, so that (for example) a resistive load has no phase difference so that the power factor is 1, while for a pure inductor the phase difference is 90 degrees and the power factor is zero.

If the rms voltage and current are expressed in complex-number form, also known as vectors or phasors, the real power is the real part of VI*, where the asterisk denotes the complex conjugate.

Another way to calculate the real power is to calculate the average value of the instantaneous power V x I. If the voltage is Vcos(wt) and the current is Icos(wt+phi) then those expressions can be multiplied together and trigonometry formulas used to show that the power factor is cos(phi) as stated.

Real power is measured from the average value of volts times amps with an instrument that contains a voltage coil and a current coil. The force produced is equal to the instantaneous power, and the instrument measures its average value muliplied by the time.

Pneumatic means "containing air", so a "pneumatic tire" means just that: a tire which is full of air.

Such tires are made of a flexible rubber compound, about the same shape as a big ring doughnut, that has to be made the right size to fit a particular size of wheel rim. The tire must have a one-way valve to allow it to be pumped full of enough air under pressure to make it roll smoothly whilst absorbing bumps from uneven road surfaces, pot-holes, etc. - yet no so hard that it bursts!

Well before pneumatic tires were invented, tires made of wood or iron were fitted to stone, wood or metal wheels to make the wheels last longer. If you don't have a separate tire, the whole wheel has to be replaced when its outside edges get chipped and worn away. So it is probable that tires were invented very soon after wheels because the people who invented wheels found out it was a good idea to have tires on them which could be replaced when they wore out.

pneumatic system use air and air has its limitation of use mainly due to its high compressibility as gas.high power applications may compress air to such an extent leading to destruction of the system.whereas hydraulics also have compressibility which is at an unnoticed level even at high pressure.

I meant motors or generators that run on air released from a reservoir of compressed air.

providing auto proportional/servo valve test bench and other electro-hydraulic automatic controlequipment and all kinds of electro-hydraulic control system integration...

SCUBA tanks are metal (usually steel or aluminum) that are filled with compressed air. This is loosely related to a pneumatic system.

As a female, she is particularly "pneumatic"- usually taken to mean that she has attractive breasts, but perhaps also meaning that she is especially exciting during intercourse

A pneumatic tyre (or in North America tire), is a tire which is inflated by air. This is in contrast to a solid rubber tire which some wheelchairs might use.

on buses for brakes and in engineerring

Whatever breaks first.

Its Green for water

Sky blue for air

Black for effluent

Brown for diesel

Aluminum for staem

Red for fire extinguisher

There is difference between Indian standards and British standard colour

coding

It all comes under Fluid dynamics/mechanics, and it's the same set of symbols for circuits. Many hydraulic symbols will include a drain to the tank. Pneumatic circuits use the atmosphere as their "tank".

Many, many places. Good examples of hydraulic systems include automotive brakes, and the control systems of large aircraft. Pneumatic systems include many types of tools found in an automotive repair shop. Both systems supply forces somewhere remote from where it is practical to locate large machinery. Hydraulics give high forces with low losses, thanks to the virtual incompressibility of hydraulic fluids. Pneumatics are usually less efficient, though simpler since the "resevoir" in the circuit is the atmosphere. That eliminates return piping and leakage problems.

The amount speed put out from any prime mover depends on the amount of energy put into the system. Hence there can be no absolute answer to your question.

Pneumatic. Pneu = Air. Hydra = liquid

Quickly. Power. Remote control.

550 to 700 kpa

You need to collect and evaluate your requirements. Load it must provide, stroke required, pressure available, end connections needed are some that come to mind.

The Haylett Formula is a composite index of labour, materials, plant and fuel. It represents the input costs of building contractors, but does not include contractors' profit margins. From Nicky Day of African Dream Building and Maintenance Services c.c.

Design pressure multiply by 1.1 equal pneumatic test pressure.

Design pressure multiply by 1.5 equal Hydrotest Pressure

Note: Design Pressure is different from Operating pressure.

Design Pressure is equal to Maximum Operating Pressure

From: galdo.gaspar@ymail.com

pump-charged gun

Air. Pneumatic systems use compressed air.

Because air is in constant supply - thus, a leak in the system won't necessarily render the brakes inoperable, whereas, with hydraulic brakes, the fluid would leak out until it had emptied.

Example:

A bicycle tire pump uses mechanical energy (your body) and converts it into pneumatic energy (air out of the hose).