I007-Level transducer type SER 2

The SER 2 level transducer is a compact device which works using the capacitive method of measurement. The level transducer can continuously measure filling levels in the defined measurement range in electrically conductive and non-conductive media.
The SER 2 level transducer has a transmitter integrated in the connecting housing and provides a level-proportional measurement current of 4-20 mA.
Capacitive filling level measurement methods are based on the principle of an electrical capacitor. If, between two condensate plates, the filling level of a dielectric changes, the current flowing through the plates also changes in proportion to the filling level. A dielectric is, by definition, an insulating substance, which does not include, however, many filling media, such as water. In order to obtain a usable measurement result nonetheless, the measurement rod that is dipped into the medium is completely insulated. After a 0-100% adjustment of the control electronics, the filling level can be read off, for example, at a remote display. The filling level measurement range can be changed during operation.

Pressure Transducer

1. Gauge pressure transducer
The pressure of the measuring medium acts on the diaphragm. The bulging on the diaphragm, which increases with rising pressure, transmits via an amplifier a steady output signal in the form of a voltage or current.
2. Pressure differential pickup
From each of the two sides, different pressures act on a diaphragm. The higher of the two pressures causes the measuring diaphragm to bulge towards the side of the lower pressure. This generates via an amplifier a steady output signal in the form of a voltage or current.
3. Operating conditions
Perm. pressure see appliance rating plate
Perm. press. differential: see appliance rating plate
Perm. ambient temp.: 0 ... +70 °C
Perm. medium temp. at
the pressure connection: max. +70 °C
Perm. transport and
storage temperature: -60 ... +70 °C
Perm. ambient humidity: Class D
Perm. power supply DC 13-30V
Max. power consumption
(DIN 40040): 30 mA
Type of encl. (DIN 40050): IP 65

Water limiter electrode E4B

The level limiter electrode E4B is, in combination with the switching amplifier B3 (see Operating Instructions H001), a level limiting devices of a "special design type". The combination of equipment recognises the minimum permitted water level LW (= low water) in steam and hot water generators.
The function of the level limiter device is based on the different conductivity of water and steam. When the level limiter electrode is immersed and removed, a bridge switching in the switching amplifier B3 is unbalanced. This signal is amplified and switches the output relay of the switching amplifier, which, with its contacts in the safety chain of the firing, triggers a fault shutdown.
The LW switching point is permanently set through the place of installation, location of the level limiter electrode and electrode rod length and can only be changed as described in Chapter 9 "Assembly".

If the level falls below the LW switching point or if the permitted monitoring current of the insulation monitoring is exceeded, then the light-emitting diode (LED) on the switching amplifier goes off, the relay in the switching amplifier returns to the starting position, and the firing is shut down due to a fault.
With steam generators, the level limiter electrode is installed in a protective pipe to avoid any dangerous incorrect operations as a result of foam formation in the boiler water (foam simulating water).
With hot water generators, it is usually installed in the supply flow adapter piece without any other protection.

low load control

1. General
A low-load control unit is incorporated as standard in everyLoos Switchgear System for oil, gas or dual fuel boilers with 2-step, 3-step or continuously variable control.This control unit prevents unnecessary energy losses as well as alternating temperature stresses of the boiler.
2. Principle of operation
When the boiler is started up, switching to burner step 2 (3) Rotary knob (1) or to continuous burner control is prevented for a preset time of up to 5 minutes. After each control shutdown
and subsequent restart of the burner, this circuit functions analogously. The burner will therefore not perform uncontrolled ON/OFF switching with moderate steamr hot water requirement.
This results in lower pre-ventilation losses as well as reducing thermal stress on the boiler walls, particularly on the firing side.
3. Setting
The timer can be set as required to between 0 - 5 minutes (each scale division corresponds to 0.5 minutes). When putting the system into operation, it is recommended to set the rotary knob to scale value 3 (1.5 minutes delay). This value can be successively increased if no difficulties are encountered during operation as a result of an excessive pressure drop after normal shutdown. If, after a normal shutdown, the pressure in the consumers drops excessively, the setting of the rotary knob (1) must be reduced in small steps by turning it anticlockwise. The longer the delay time, the less energy consumption and the less boiler wear firing operation will entail. The luminous indicator N (green) indicates when voltage is applied to the time-lag relay. The luminous indicator R (red) light up when the delay time has elapsed.
4. Malfunctions
Pressure/temperature drop after control shutdown on the consumer too high:
Cause: Time-lag relay set to too long a delay.
Remedy: Reduce the rotary knob's setting in small steps by turning is anticlockwise.

people choose electric car

Electric cars are not a new concept as we think, people hve been using them for a long time .In fact in the 1900's people used more electric cars than cars run on gas.In the 1920's when the popularity for cars was growing, gas was very costly.Starting a gas run car was also a very tedious process, there was no key to ignite the engine, in fact a rod used to fit into the front of the car which had to be turned round and round to get the car started.

Not only were gas run cars tedious to start , they emitted alot of smoke and were very noisy, as either the mufflers used were not good or there were no mufflers at all. Beleive it or not , at one point of time electric cars were so popular that there were about 50,000 electric cars running on the streets of United States .

As new discoveries were underway to make gasoline cheaper, electric cars started disappearing from the market. The discovery of the electric starter made way for the exit of the crank and the car was started with a key.A car run on gas could travel more distance than the electric car.Thus cars run on gas started getting more pouplar than the electric car.

Now, once again because of the awareness towards protecting the environment and reducing the dangers caused by the emission of the greenhouse gases " green " electric cars are once again getting
popularized.

Gasoline is not used to run an electric car, it runs on the energy stored in batteries in the car. 12,14 or more batteries may be needed to run the car.The operation of the electric car is similar to that a remote controlled one since both have an electric motor that turns the wheel and a battery that that runs the motor.

Charging of the batteries can either be done all night or some cars need to be plugged into a standard electric wall.There are some which need a large electric outlet, something like what is used for an electric stove or electric clothes dryer. These are the various ways electricity is stored in the cars.

The batteries used to run the cars have to be either lead acid batteries, similar to those used in torch lights or ni-cad (nickel-cadium) used to run portable viodeo recorders or video games , only much larger in size. A lot of work is going on to upgrade the batteries to hold more energy and last longer. By the time the fifth graders in 2001 are ready to drive we should have electric cars which will be able to travel 150 to 200 miles before needing to get recharged.

Manufacturers of cars and scientists are making constant endeavours to make better cars which will be more eco-friendly. The revival of electric cars and the challenge to make them more attractive is on in a big way and enticing more people to switch over to electric cars.

Retrieved from "http://www.articlesbase.com/environment-articles/electric-car-popularity-reasons-people-prefer-electric-cars-to-gas-cars-774709.html"

batteray in electic car

Rechargeable battery materials used in electric vehicles include lead-acid ("flooded" and VRLA), NiCd, nickel metal hydride, lithium-ion, Li-ion polymer, and, less commonly, zinc-air and molten salt. The Lithium iron phosphate battery is currently one of the most promising electric vehicle battery variants due to its light weight, high specific energy, and lack of thermal runaway issues that have plagued laptop computer lithium-ion batteries. The amount of electricity stored in batteries is measured in ampere hours or coulombs, with the total energy often measured in watt hours.

Historically, EVs and PHEVs have had problems with high battery costs, limited range between battery recharging, charging time, and battery lifespan, which have limited their widespread adoption. Ongoing battery technology advancements have reduced many of these problems; many models have recently been prototyped, and a few future production models have been announced.

from: wikipedia

Acceleration and drivetrain design in electric car

Electric motors can provide high power to weight ratios, and batteries can be designed to supply the large currents to support these motors.

Although some electric vehicles have very small motors, 15 kW (20 hp) or less and therefore have modest acceleration, many electric cars have large motors and brisk acceleration. In addition, the relatively constant torque of an electric motor, even at very low speeds tends to increase the acceleration performance of an electric vehicle relative to that of the same rated motor power internal combustion engine. Another early solution was American Motors’ experimental Amitron piggyback system of batteries with one type designed for sustained speeds while a different set boosted acceleration when needed.

Electric vehicles can also use a direct motor-to-wheel configuration which increases the amount of available power. Having multiple motors connected directly to the wheels allows for each of the wheels to be used for both propulsion and as braking systems, thereby increasing traction. In some cases, the motor can be housed directly in the wheel, such as in the Whispering Wheel design, which lowers the vehicle's center of gravity and reduces the number of moving parts. When not fitted with an axle, differential, or transmission, electric vehicles have less drivetrain rotational inertia.

When the foot is lifted from the accelerator of an ICE, engine braking causes the car to slow. An EV would coast under these conditions, and applying mild regenerative braking instead provides a more familiar response.

A gearless or single gear design in some EVs eliminates the need for gear shifting, giving such vehicles both smoother acceleration and smoother braking. Because the torque of an electric motor is a function of current, not rotational speed, electric vehicles have a high torque over a larger range of speeds during acceleration, as compared to an internal combustion engine. As there is no delay in developing torque in an EV, EV drivers report generally high satisfaction with acceleration.

For example, the Venturi Fetish delivers supercar acceleration despite a relatively modest 220 kW (295 hp), and top speed of around 160 km/h (100 mph). Some DC motor-equipped drag racer EVs, have simple two-speed transmissions to improve top speed. The Tesla Roadster prototype can reach 100 km/h (62 mph) in 4 seconds with a motor rated at 185 kW (248 hp).