استخدامات اخرى للالكترونيات - مضخات النفط .. الالكترونيات

Other Uses of Electronics - Oil Pumps .. Electronics

Other Uses of Electronics

Electronics are useful for doing unusual things. Usually, a certain process can be done using a special electronic circuit.

Oil Pumps

Electronic oil pumps can replace regular electric pumps and consist of coils placed on the pump and are at the same time low frequency vibrating coils (266) that raise and lower the collector current and the coil current. Valves in the piston or cylinder convert the rapid movement of the piston into a constant and stable pressure for the oil pipe that is applied to a special spring, and it works to supply the pump's burner with the necessary fuel.

Timer

The timer is used to automatically time short periods and repeat them whenever necessary.

Figure (267) shows an electronic timer that works by the time constant of the capacitor S. The collector current of the transistor keeps the relay core in the down position and does not leave it except when its value decreases, then it rises by itself. In addition, the variable resistance is calibrated in seconds. Opening and closing the relay contacts is used to control the operation of various devices in time.

Current control

The silicon rectifier can be controlled - i.e. opened and closed by applying a specific current to its control path (268).

Silicon rectifiers are used to operate motors and devices that require high power.

266 - Transistor fuel pump for vehicles.

267 - Transistor time limiter.

268 - Silicon rectifier controlled with its circuit.

269 - Power pulse width control.

270 - Brushless DC motor.

The switches that include a control gate are somewhat similar to silicon rectifiers, by which the speed of a DC motor can be reduced by a variable resistor that reduces the voltage entering the motor (269A), but this leads to a loss of power in the form of heat lost in the resistor. Another way to reduce the speed of the motor is by using a wide pulse oscillator to control a solid-state rectifier that supplies the motor with the necessary current. In Figure (269B), the current is present all the time the speed reaches its maximum, while in Figure (269C), the current is disconnected for short periods to reduce the average speed of the motor. In positions (269D) and (369E), the periods of disconnection are longer, and thus increase the speed reduction without any energy lost in the form of heat.

Brushless DC Motor

The brush of a DC motor is characterized by being noisy, it wears out easily, and the resulting spark is sometimes dangerous. The brushless DC motor uses power transistors to produce an oscillating current (270). It also has a pole with shaded coils like those used in AC motors and does not need a commutator or a brush.