The regulating relay of tension of the generator is the important device of electrical system of the vehicle. It carries out stabilization of voltage level in the set range that ensures normal functioning of the car.
Any option of workmanship of the generating equipment provides the voltage controller. Irrespective of rotating speed of the rotor the automatic stabilization system of tension allows to provide the parameter, necessary for electric equipment. If to consider the basic principle of work of this engineering device, then in the general words it is possible to tell that tension at the output of the generator in direct ratio the rotor rotational speed which can be regulated by intensity of current given on its winding.
General concepts
It is important to understand of what constructive parts the automobile generator consists.
The rotor creates electromagnetic field on the winding of excitation.
The stator removing alternating voltage in the range from 12-30 Volts has three windings which are connected according to the scheme "star".
The zigzag rectifier which consists of six diode semiconductors.
As change of voltage level in the generator can happen in rather big range, its normal work first of all is connected with the device of automatic regulation. It should be noted, for example, that the regulating relay on the VAZ 2107 cars irrespective of workmanship of fuel injection system (injector or the carburetor) has identical design. It consists of the following devices: the comparing, operating, setting and executive and also special sensor. Basic element of this design is the body of regulation which is mechanical and electric.
At rotation of the rotor in the generator unit of the car at its exit there is voltage which level on winding of excitation is operated by body of adjustment. Besides, the generator is directly connected to the storage battery because of what on excitation winding tension constantly moves. At change of rotational speed of the rotor there is also tension variation at the output of the generator which is regulated by the regulating relay connected to it.
Increase and lowering of the level of tension at the output of the generator unit of the car is made as follows. At first the sensor fixes its change and gives the corresponding signal on the comparing device which in turn compares it with the put level. Then this signal arrives on control device where its transformation and giving on operating mechanism is carried out. And already adjustment device is engaged in change of intensity of current arriving on rotor winding owing to what at the output of the generator there is reduction or increase in size of tension.
What types of devices often meet
The simplest in design the two-level regulator is considered. It consists the generator, the rectifier and the accumulator. The winding of the electric magnet which is the cornerstone of adjustment device connects in this case to the sensor. As the setting device the ordinary spring is used here, and role of the comparing device (switching) is played by the lever of the small sizes. The contact unit works as operating mechanism. Constant resistance is body of adjustment. Despite the outdated scheme of this regulating relay, such design still meets rather often.
Operation of the two-level regulator happens as follows. Tension which has appeared at the output of the generator arrives on relay winding. The arisen electromagnetic field attracts lever arm which the spring of the comparing device influences. During creation of tension exceeding the set parameters, contacts of the relay are disconnected, and the direct current which level is much less comes to electrical circuit. Respectively at reduction of tension there is short circuit of contacts of the relay because of what current intensity begins to increase.
As the above-stated two-level regulators differ in excessive wear of mechanical elements, modern voltage controllers began to use the semiconductors of a such type working as keys instead of the electromagnetic relay. In this case the operation principle of regulating relays has not changed, however replacement of mechanical parts by radio-electronic is followed by the fact that the sensitivity of the voltage divider executed on constant resistors significantly has increased. Besides, as the setting device the stabilitron is used here.
The modern voltage controllers of the generator used, for example, in domestic cars are rather reliable and durable devices. In them executive part works on semiconductor transistors. Besides, at the output of the generator after the electronic key serving as the switchboard if necessary also additional resistance can be connected.
It should be noted that the overall performance of three-level designs of voltage regulation considerably increases. Despite their general basic similarity to mechanical two-level regulating relays, after all there are also differences. In them information processing about voltage level at the output of the generator moves through divider on the special scheme. Any car can be equipped with such regulators. In this case it is important to deal with its device and the scheme of connection only.
In three-level regulating relays of tension of generators the comparison of its current indicator with extreme (min and max) values is carried out. In this case at voltage level deviation from the set parameters there is forming of signal of mismatch which influences regulation of current intensity on winding of excitation of the rotor. Besides, the scheme of such regulator means availability of several additional resistance which are after electronic key.
It is necessary to know that the modern systems of voltage regulation on expensive cars use more perfect multilevel devices which contain from three and more additional resistance in the schemes. In addition in them the watching systems of regulation can be applied. And in some models of cars instead of additional resistance are used the principle of increase in frequency of operation of key. The last developments of multilevel guidance systems are based on frequency modulation. In them additional resistance operate logical constructive parts.
As dismantling of the regulating relay is made
To remove the regulating relay it is not necessary to have any special skills and to use difficult tools. It is enough to have the screw-driver ("minus" or "plus") and to be guided by simple rules.
As a rule, the regulator is on back cover of the automobile generator. And for its dismantling it is not required to remove the generator or its drive. The output of the device can come from operating condition at full deleting of graphite brushes or breakdown of semiconductor element. And removal of the regulator needs to be begun with shutdown of the accumulator. Further it is necessary to disconnect the regulator from the generator, having turned off the screw-driver fixture. After this rather simple manipulation it is possible to extend outside tension regulating relay body.
Check of working capacity
Operating condition of the device can be established by survey of brushes which length has to be not less than 5 mm. And diagnosing condition of the regulator is made by use of constant voltage source on which it is possible to change initial parameter. For these purposes it is enough to have the accumulator, pair of finger-type batteries and the normal glow lamp on 12 Volts or the voltmeter.
At first it is necessary "+" to connect from power supply to the corresponding connector of the regulating relay, and "-" - to the general plate of the device. Further the lamp or the voltmeter is connected to brushes on which voltage of 12 Volts moves at this time. It is important to understand that when giving on the regulator over 15 Volts between brushes will be absent tension. It also demonstrates to operating condition of the device. The knot will be diagnosed as faulty in cases when the control lamp does not light up or burns at any value of tension.