Problems of “undercharging”, as well as “overcharging” of the battery in principle, can be caused by many reasons, but the very first and most common on many cars (our VAZs are no exception here), as well as on many motorcycles, is the output of the generator relay-regulator from building. This device, despite its compactness, will protect your battery and make its service life much longer. However, if they fail, it can simply kill the battery in a matter of weeks, so if you see white streaks, and also, the engine does not start after night, even the starter does not “turn” - it’s time to check the relay regulator of your car, and here’s how it works do it yourself, and today I’ll tell you in detail...
To begin with, the definition
Relay regulator is a device that regulates the current from the car’s generator, preventing the battery from overcharging, protecting it from overcharging, which is detrimental to the battery. Thus, this device greatly extends the battery life.
Essentially, this is just a voltage stabilizer that prevents the voltage from the generator from exceeding the threshold of 14.5 Volts; it is a very accurate device and is required for all types of cars. However, it can be distinguished into two types.
Types of relay-regulator
To exaggerate, there are only two types, but each works on the same principle, namely, “cuts” or increases the voltage to the desired level.
- Combined with brush assembly. Usually it is mounted on the generator itself, in the housing where the brushes are located, there is also a relay regulator.
- Separate. Usually it is mounted on the car body, the wires go from the generator to it, and only then to the battery.
The housings are non-separable and tight and of a different type (often filled with sealants or special adhesives), that is, they cannot be repaired. To be honest, they are quite cheap, especially for our VAZs, so it’s easier to buy a new one than to tinker with an old one.
These are the most common types, of course, previously there were so-called ones combined with terminals, but they didn’t catch on because the device is not very convenient, so I won’t talk about them.
If your relay is “broken” and is constantly recharging, then it’s worth changing it, but first you need to make sure that this is the problem. Now there are only two ways to check: - without removing it on the car itself, and checking an already removed relay. Let's look at both options.
How to check the relay - regulator without removing it from the car?
Indirect signs
If your “regulator” is out of order, you will notice it very quickly, especially if it is winter and frost outside. The fact is that there will be either an “undercharge”. When undercharged - you simply won’t start your car - you come to the parking lot, insert the key, and the car barely turns the engine, or doesn’t start at all, sometimes even the lights go out.
When recharging – almost the same thing will happen, only the reason will be boiling away of the electrolyte from the battery cans. It can be indirectly determined by the rapid decrease in electrolyte in the banks, and a white coating on the top of the battery, as well as on parts of the body underneath it. It’s worth thinking about it and checking the regulator relay.
However, this is not our method, we need to make sure more precisely.
Correct method
To do this, we will use our voltmeter; we need to measure the voltage at the battery terminals with the engine running. To begin with, I would like to note that when the engine is not running it should be within 12.7V, perhaps a little less, but if you already have 12V, then the battery needs to be recharged! Or look for reasons for undercharging.
- Start the engine
- We set it to a value of up to 20 Volts
- Connecting the probes to the terminals
- If the voltage is approximately 13.2 - 14V, this is normal.
- We increase the speed (say to 2000 - 2500), the voltage will begin to increase, from about 13.6 to 14.2 V, this is also normal.
- Next, we try at maximum speed (more than 3500), the voltage should be from 14 to 14.5V, but no more!
If you have deviations, up or down, namely at any speed the voltage remains at 12.7V, or even drops to 12V, then this indicates a malfunction of the relay regulator.
Also, if the voltage is higher than 14.5V, for example - 15 - 16V, again the relay regulator is faulty and needs to be replaced.
To be completely honest, it is not always the relay that indicates a malfunction; often the generator itself fails. If the “regulator” is located separately, then you need to change it first; if nothing has changed, remove the generator and completely check the system. If the brush assembly is combined with the relay, then the generator must be removed!
Checking the combined relay-regulator of the car
First we will check the combined relay-regulator circuit together with the brush assembly. These are now installed on many foreign cars, and by the way, on many domestic cars (often labeled Y212A).
As you understand, it is necessary to remove the generator and disassemble it, since this combined unit is attached at the back next to the generator shaft, along which these brushes run. For this:
- We look for a special “window” on the back of the generator where the brushes are immersed.
- Unscrew the fastening bolt.
- Remove the brush assembly.
- We clean it - as a rule, it will be covered in graphite dust; the brushes are made of graphite, using special carbon.
Then we need to check it, but for this we assemble a certain circuit, it is advisable to use a power supply with an adjustable load or a charger. We also need to take a regular 12V light bulb from a car, for example from a “dimensions”, we will need wires to assemble the entire system.
We may need a battery, because many chargers do not work without it. But from the wire from the battery we connect the relay-regulator, to the brushes of which we connect a 12V light bulb, this can be done with small alligator clips, the main thing is not to break the graphite elements. A small diagram for understanding.
If you connect everything in a calm state, the light will simply light up and stay lit, this is normal, since the brush assembly is a conductor of electricity from the shaft. Let me remind you that in a calm state, the voltage on the brushes will be approximately 12.7V.
Now we need to raise the voltage on the charger to 14.5 V, the lamp will light, but when this threshold is reached it should go out! That is, 14.5 V is a kind of “cutoff” for a further increase in voltage! If you lower the value, the lamp should light up again. Then your relay-regulator is working, it passed the test.
If the voltage reaches 15 - 16V and the light is on, this means the relay has failed and needs to be replaced! It does not cause a “cut-off” and will help recharge the battery. Here's a simple check. Now a short video on the topic.
Testing an Individual Relay
Similarly, you can check a new type of regulator, that is, a separate one, here the verification process is much easier. For example, let’s take a model like Y112B; they were installed on many domestic cars before (VAZ).
This is a separate element, so we simply unscrew it from the body (sometimes from the generator cover) and attach it to our stand. Once again, I would like to remind you that it is advisable to have a 12V power supply, then the testing process will be much easier. If not, we use a charger (with adjustment modes) and connect it according to the lower diagram.
The check is the same, we increase the voltage to 14.5 V, the lamp should go out, if not, or turns off at a voltage much higher, then the relay has failed and needs to be replaced.
Old type or check 591.3702-01
This is a very old type of relay; it was installed on “penny” cars, as well as on many rear-wheel drive cars. It has also always been separately mounted on the body, but the check here is slightly different in terms of contacts.
If you take their markings, then there are only two of them - “67” and “15”. The first contact “67” is a minus, as is the relay body itself, but “15” is a plus. The principle of operation is the same, we connect our charger - we start checking, increase the voltage to 14.5V, then look at the lamp. If it turns off well, no, it’s bad, replace it.
Rice. 1. Methods of controlling the excitation current: G - generator with parallel excitation; W in - excitation winding; R d - additional resistance; R - ballast resistance; K - current switch (regulating body) in the excitation circuit; a, b, c, d, e are indicated in the text.
A modern automobile internal combustion engine (ICE) operates over a wide speed range (900:.. 6500 rpm). Accordingly, the rotor speed of the automobile generator changes, and therefore its output voltage.
The dependence of the generator output voltage on the internal combustion engine speed is unacceptable, since the voltage in the vehicle's on-board network must be constant, not only when the engine speed changes, but also when the load current changes. The function of automatic voltage regulation in a car generator is performed by a special device - car generator voltage regulator. This material is devoted to the consideration of voltage regulators of modern automobile alternators.
Voltage regulation in generators with electromagnetic excitation
Methods of regulation. If the main magnetic field of the generator is induced by electromagnetic excitation, then the electromotive force E g of the generator can be a function of two variables: the rotor rotation frequency n and the current I in the excitation winding - E g = f(n, I in).
It is this type of excitation that takes place in all modern automobile alternating current generators that operate with a parallel excitation winding.
When the generator operates without load, its voltage U g is equal to its electromotive force EMF E g:
U g = E g = SF n (1).
Voltage U g of the generator under load current I n is less than the emf E g by the amount of voltage drop across the internal resistance r g of the generator, i.e. we can write that
E g = U g + I n r g = U g (1 + β) (2).
The value β = I n r g /U g is called the load factor.
From a comparison of formulas 1 and 2 it follows that the generator voltage
U g = nSF/(1 + β), (3)
where C is a constant design factor.
Equation (3) shows that both at different frequencies (n) of rotation of the generator rotor (n = Var), and with a changing load (β = Var), the constant voltage U g of the generator can only be obtained by a corresponding change in the magnetic flux F.
The magnetic flux F in a generator with electromagnetic excitation is formed by the magnetomotive force F in = W I in the excitation winding W in (W is the number of turns of the winding W in) and can be easily controlled using the current I in the excitation winding, i.e. Ф = f (I in). Then U g = f 1, which allows you to keep the voltage U g of the generator within the specified control limits for any changes in its speed and load by appropriately selecting the control function f (I in).
The automatic regulation function f(Iv) in voltage regulators comes down to reducing the maximum value of the current Iv in the excitation winding, which occurs when Iv = U g /R w (Rw is the active resistance of the excitation winding) and can be reduced in several ways ( Fig. 1): by connecting to the winding W in parallel (a) or in series (b) an additional resistance R d: by short-circuiting the excitation winding (c); rupture of the excitation current circuit (d). The current through the excitation winding can be increased by short-circuiting the additional series resistance (b).
All these methods change the excitation current in steps, i.e. There is intermittent (discrete) current regulation. In principle, analogue regulation is also possible, in which the value of the additional series resistance in the excitation circuit changes smoothly (d).
But in all cases, the voltage Ug of the generator is kept within the specified control limits by corresponding automatic adjustment of the excitation current value.
Discrete - pulse control
In modern automobile generators, the magnetomotive force F in the excitation windings, and hence the magnetic flux F, is changed by periodic interruption or an abrupt decrease in the excitation current I with a controlled interruption frequency, i.e. discrete-pulse regulation of the operating voltage U g of the generator is used (previously analog regulation was used, for example, in carbon voltage regulators).
The essence of discrete-pulse regulation will become clear from a consideration of the principle of operation of a generator set, consisting of a simple contact-vibration voltage regulator and an alternating current generator (ACG).
Rice. 2. Functional (a) and electrical (b) diagrams of a generator set with a vibration voltage regulator.
A functional diagram of a generator set operating in conjunction with an on-board battery (AB) is shown in Fig. 2a, and the electrical diagram is in Fig. 26.
The generator consists of: phase windings W f on the stator ST, a rotating rotor R, a power rectifier VP on semiconductor diodes VD, an excitation winding W in (with active resistance R w). The generator rotor receives mechanical rotational energy A m = f (n) from the internal combustion engine. The vibration voltage regulator RN is made on an electromagnetic relay and includes a switching element CE and a measuring element IE.
The switching element CE is a vibrating electrical contact K, which makes or breaks an additional resistance Rd, which is connected in series with the excitation winding W of the generator. When the switching element is triggered (opening contact K), a signal τR d is generated at its output (Fig. 2a).
The measuring element (IE, in Fig. 2a) is that part of the electromagnetic relay that implements three functions:
- comparison function (CS) of the mechanical elastic force F n of the return spring P with the magnetomotive force F s = W s I s of the relay winding S (W s is the number of turns of the winding S, I s is the current in the relay winding), and the result of the comparison is the formed in a gap with period T (T = t p + t h) armature oscillations N;
- the function of the sensitive element (SE) in the feedback circuit (DSP) of the voltage regulator, the sensitive element in vibration regulators is the winding S of the electromagnetic relay, connected directly to the voltage U g of the generator and to the battery (to the latter through the ignition key VZ);
- the function of a master device (SD), which is implemented using a return spring P with an elastic force F p and a support force F o.
The operation of a voltage regulator with an electromagnetic relay can be clearly explained using the speed characteristics of the generator (Fig. 3 and 4).
Rice. 3. Change in U g, I c, R b in time t: a - dependence of the current value of the generator output voltage on time t - U g = f (t); b - dependence of the current value in the excitation winding on time - I in = f (t); c - dependence of the arithmetic mean value of the resistance in the excitation circuit on time t - R b = f(t); I is the time corresponding to the frequency (n) of rotation of the generator rotor.
While the voltage U g of the generator is lower than the voltage U b of the battery (U g
As the engine speed increases, the generator voltage increases and when a certain value is reached U max) > U b) the magnetomotive force F s of the relay winding becomes greater than the force F p of the return spring P, i.e. F s = I s W s > F p. The electromagnetic relay is activated and contact K opens, and additional resistance is connected to the excitation winding circuit.
Even before contact K opens, the current I in the excitation winding reaches its maximum value I in max = U g R w > I vb, from which, immediately after contact K opens, it begins to fall, tending to its minimum value I in min = U g /(R w + R d). Following the drop in the excitation current, the generator voltage begins to decrease accordingly (U g = f(I in), which leads to a drop in the current I s = U g /R s in the relay winding S and contact K is opened again by the force of the return spring P (F p > F s). By the time contact K opens, the generator voltage U g becomes equal to its minimum value U min, but remains slightly higher than the battery voltage (U g min > U b).
Starting from the moment contact K opens (n = n min, Fig. 3), even with a constant frequency n of rotation of the generator rotor, armature N of the electromagnetic relay enters the mode of mechanical self-oscillations and contact K, vibrating, begins periodically, with a certain switching frequency f to = I/T = I/(t p + t h) then close and then open the additional resistance R d in the generator excitation circuit (green line in the section n = n av = const, Fig. 3). In this case, the resistance R in the excitation current circuit changes stepwise from the value of R w to the value of R w + R d.
Since during operation of the voltage regulator, contact K vibrates with a sufficiently high frequency f to commutation, then R in = R w + τ r where the value of τ r is the relative time of the open state of contact K, which is determined by the formula τ r = t r /( t з + t р), I/(t з + t р) = f к - switching frequency. Now the average value of the excitation current established for a given switching frequency f can be found from the expression:
I in avg = U g avg /R in = U g avg /(R w +τ r R d) = U g avg /(R w + R d t r /f k),
where R in is the arithmetic mean (effective) value of the pulsating resistance in the excitation circuit, which, with increasing relative time τ p of the open state of contact K, also increases (green line in Fig. 4).
Rice. 4. Speed characteristics of the generator.
Processes during switching with excitation current
Let us consider in more detail what happens during switching with the excitation current. When contact K is closed for a long time, the maximum excitation current I in = U g / R w flows through the excitation winding W.
However, the excitation winding W of the generator is an electrically conductive coil with high inductance and a massive ferromagnetic core. As a result, the current through the excitation winding after closing contact K increases with deceleration. This happens because the rate of current increase is hampered by hysteresis in the core and the self-inductive emf of the coil counteracting the increasing current.
When contact K opens, the excitation current tends to a minimum value, the value of which, with a long-open contact, is determined as I in = U g /(R w + R d). Now the self-induction EMF coincides in direction with the decreasing current and somewhat prolongs the process of its decrease.
From the above it follows that the current in the excitation winding cannot change instantly (abruptly, like additional resistance R d) either when closing or opening the excitation circuit. Moreover, at a high vibration frequency of the contact K, the excitation current may not reach its maximum or minimum value, approaching its average value (Fig. 4), since the value t r = τ r / f k increases with increasing frequency f k switching, and the absolute time t from the closed state of contact K decreases.
From a joint consideration of the diagrams shown in Fig. 3 and fig. 4, it follows that the average value of the excitation current (red line b in Fig. 3 and Fig. 4) with increasing speed n decreases, since at the same time the arithmetic mean value (green line in Fig. 3 and Fig. 4) of the total, pulsating in time, resistance R in the excitation circuit (Ohm's law). In this case, the average value of the generator voltage (U avg in Fig. 3 and Fig. 4) remains unchanged, and the output voltage U g of the generator pulsates in the range from U max to U min.
If the generator load increases, then the regulated voltage U g initially drops, while the voltage regulator increases the current in the field winding so much that the generator voltage rises back to its original value.
Thus, when the generator load current changes (β = V ar), the regulation processes in the voltage regulator proceed in the same way as when the rotor speed changes.
Regulated voltage ripple. At a constant frequency n of rotation of the generator rotor and at a constant load, the operating pulsations of the excitation current (ΔI in Fig. 46) induce corresponding (in time) pulsations of the regulated voltage of the generator.
The amplitude of the pulsations ΔU g - 0.5(U max - U min)* of the voltage regulator U g does not depend on the amplitude of the tone ripples ΔI in the excitation winding, since it is determined by the control interval specified using the measuring element of the regulator. Therefore, the voltage pulsations Ug at all generator rotor speeds are almost identical. However, the rate of rise and fall of voltage U g in the regulation interval is determined by the rate of rise and fall of the excitation current and, ultimately, by the rotation frequency (n) of the generator rotor.
* It should be noted that ripple 2ΔU g is an inevitable and harmful side effect of the operation of the voltage regulator. In modern generators, they are connected to ground by a shunt capacitor Сш, which is installed between the positive terminal of the generator and the housing (usually Сш = 2.2 μF)
When the load of the generator and the rotational speed of its rotor do not change, the vibration frequency of contact K is also unchanged (f к = I/(t з + t р) = const). In this case, the voltage U g of the generator pulsates with an amplitude ΔU р = 0.5(U max - U min) around its average value U avg.
When the rotor speed changes, for example, towards an increase or when the generator load decreases, the time t from the closed state becomes less than the time t p of the open state (t
As the generator rotor frequency decreases (n↓), or as the load increases (β), the average value of the excitation current and its ripple will increase. But the generator voltage will continue to fluctuate with an amplitude ΔU g around a constant value U g avg.
The constancy of the average voltage value Ug of the generator is explained by the fact that it is determined not by the operating mode of the generator, but by the design parameters of the electromagnetic relay: the number of turns Ws of the relay winding S, its resistance Rs, the size of the air gap σ between the armature N and the yoke M, as well as force F p of the return spring P, i.e. the value U avg is a function of four variables: U av = f(W s, R s, σ, F p).
By bending the support of the return spring P, the electromagnetic relay is adjusted to the value U cf in such a way that at the lower rotor speed (n = n min - Fig. 3 and Fig. 4), contact K would begin to open, and the excitation current would have time to reach its maximum value I in = U g / R w. Then the pulsations ΔI in and time t z of the closed state are maximum. This sets the lower limit of the controller operating range (n = n min). At average rotor speeds, time t s is approximately equal to time t p, and the pulsations of the excitation current become almost two times smaller. At rotation frequency n, close to the maximum (n = n max - Fig. 3 and Fig. 4), the average value of the current I in and its pulsations ΔI in are minimal. At n max, the regulator's self-oscillations fail and the generator voltage U g begins to increase in proportion to the rotor speed. The upper limit of the operating range of the regulator is set by the value of the additional resistance (at a certain resistance value R w).
conclusions. The above about discrete pulse regulation can be summarized as follows: after starting the internal combustion engine (ICE), with an increase in its speed, there comes a moment when the generator voltage reaches the upper control limit (U g = U max). At this moment (n = n min) the FE switching element in the voltage regulator opens and the resistance in the excitation circuit increases stepwise. This leads to a decrease in the excitation current and, as a consequence, to a corresponding drop in voltage U g of the generator. A drop in voltage U g below the minimum control limit (U g = U min) leads to reverse closure of the FE switching element and the excitation current begins to increase again. Further, from this moment, the voltage regulator enters the self-oscillation mode and the process of current switching in the generator excitation winding is periodically repeated, even at a constant generator rotor speed (n = const).
With a further increase in the rotation frequency n, proportional to it, the time t from the closed state of the FE switching element begins to decrease, which leads to a smooth decrease (in accordance with the increase in frequency n) of the average value of the excitation current (red line in Fig. 3 and Fig. 4) and amplitudes ΔI in its pulsation. Due to this, the voltage U g of the generator also begins to pulsate, but with a constant amplitude ΔU g around its average value (U g = U avg) with a fairly high oscillation frequency.
The same processes of switching current Iv and voltage ripple Ug will also take place when the generator load current changes (see formula 3).
In both cases, the average voltage value U g of the generator remains unchanged throughout the entire operating range of the voltage regulator at frequency n (U g av = const, from n min to n max) and when the generator load current changes from I g = 0 to I g = max .
This is the basic principle of regulating the generator voltage by intermittently changing the current in its field winding.
Electronic voltage regulators for automobile generators
The vibration voltage regulator (VVR) with an electromagnetic relay (EM relay) discussed above has a number of significant disadvantages:
- as a mechanical vibrator, the VRN is unreliable;
- contact K in the EM relay burns out, which makes the regulator short-lived;
- VVR parameters depend on temperature (the average value U avg of the operating voltage U g of the generator floats);
- The VVR cannot operate in the mode of complete de-energization of the excitation winding, which makes it low-sensitive to changes in the generator output voltage (high voltage ripple U g) and limits the upper limit of the voltage regulator operation;
- electromechanical contact K of the electromagnetic relay limits the maximum excitation current to 2...3 A, which does not allow the use of vibration controllers on modern powerful alternating current generators.
With the advent of semiconductor devices, it became possible to replace the K contact of the EM relay with the emitter-collector junction of a powerful transistor with its base control by the same contact K of the EM relay.
This is how the first contact-transistor voltage regulators appeared. Subsequently, the functions of the electromagnetic relay (SU, CE, UE) were fully implemented using low-level (low-level) electronic circuits on semiconductor devices. This made it possible to produce purely electronic (semiconductor) voltage regulators.
A feature of the operation of the electronic regulator (ER) is that it does not have an additional resistor Rd, i.e. in the excitation circuit, the current in the excitation winding of the generator is almost completely switched off, since the switching element (transistor) in the closed (open) state has a fairly high resistance. This makes it possible to control a larger excitation current and at a higher switching speed. With such discrete-pulse control, the excitation current has a pulsed nature, which makes it possible to control both the frequency of current pulses and their duration. However, the main function of the ERN (maintaining a constant voltage Ug at n = Var and β = Var) remains the same as in the ERN.
With the development of microelectronic technology, voltage regulators first began to be produced in a hybrid design, in which unpackaged semiconductor devices and mounted miniature radio elements were included in the electronic circuit of the regulator along with thick-film microelectronic resistive elements. This made it possible to significantly reduce the weight and dimensions of the voltage regulator.
An example of such an electronic voltage regulator is the YA-112A hybrid-integral regulator, which is installed on modern domestic generators.
Regulator Ya-112A(see diagram in Fig. 5) is a typical representative of the circuit solution to the problem of discrete-pulse regulation of the generator voltage U g by the excitation current I v. But in design and technological design, currently produced electronic voltage regulators have significant differences.
Rice. 5. Schematic diagram of the Ya-112A voltage regulator: R1...R6 - thick-film resistors: C1, C2 - mounted miniature capacitors; V1...V6 - unpackaged semiconductor diodes and transistors.
As for the design of the YA-112A regulator, all of its semiconductor diodes and triodes are unpackaged and mounted using hybrid technology on a common ceramic substrate together with passive thick-film elements. The entire regulator unit is sealed.
The Ya-112A regulator, like the vibration voltage regulator described above, operates in an intermittent (switch) mode, when the excitation current control is not analog, but discrete-pulse.
The principle of operation of the voltage regulator Ya-112A of automobile generators
As long as the voltage U g of the generator does not exceed a predetermined value, the output stage V4-V5 is in a constantly open state and the current I in the field winding directly depends on the voltage U g of the generator (section 0-n in Fig. 3 and Fig. 4). As the generator speed increases or its load decreases, U g becomes higher than the response threshold of the sensitive input circuit (V1, R1-R2), the zener diode breaks through and the output stage V4-V5 closes through the amplifying transistor V2. In this case, the current I in the excitation coil is turned off until U g again becomes less than the specified value U min. Thus, when the regulator operates, the excitation current flows through the excitation winding intermittently, changing from Iv = 0 to Iv = Imax. When the excitation current is cut off, the generator voltage does not immediately drop, since there is inertia in the demagnetization of the rotor. It may even increase slightly with an instantaneous decrease in the generator load current. The inertia of magnetic processes in the rotor and the self-inductive emf in the excitation winding exclude an abrupt change in the generator voltage both when the excitation current is turned on and when it is turned off. Thus, the sawtooth ripple voltage U g of the generator remains even with electronic regulation.
The logic for constructing a circuit diagram of an electronic regulator is as follows. V1 - zener diode with divider R1, R2 form an input current cut-off circuit I in at U g > 14.5 V; transistor V2 controls the output stage; V3 - blocking diode at the input of the output stage; V4, V5 - powerful transistors of the output stage (composite transistor), connected in series with the excitation winding (switching element FE for current I V); V6 shunt diode to limit the EMF of the self-induction of the excitation winding; R4, C1, R3 feedback chain, accelerating the process of cutting off the excitation current I.
An even more advanced voltage regulator is an electronic regulator in an integrated design. This is a design in which all of its components, except for the powerful output stage (usually a composite transistor), are implemented using thin-film microelectronic technology. These regulators are so miniature that they take up virtually no volume and can be installed directly on the generator housing in the brush holder.
An example of the design of the IRI is the BOSCH-EL14V4C regulator, which is installed on alternating current generators with a power of up to 1 kW (Fig. 6).
As you know, in any vehicle the generator is one of the main components, the failure of which will not allow the engine to start. Such a device consists of many components, but one of the most basic is a three-level regulator. What is this voltage device, what is its purpose, what types are there, how to diagnose - read below.
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Characteristics of the voltage regulator
How much voltage should the generator produce, what types of remote relays are there, how does the element work? What are the signs of a malfunction, how to increase or increase the output, what to do if the voltage jumps? First of all, it is necessary to understand the issues of design and purpose.
Purpose
So, what are the signs of a malfunction, what functions does a three-level voltage regulator perform? When the engine of any car starts, first of all, under the influence of direct current, the crankshaft begins to work. It is because of the direct current that it begins to set the movement of the rotor, and only after these actions does the car generator directly begin to work. A three-level voltage regulator monitors all these processes; this element is also often called a DC relay.
Without this device, the current in the on-board network will not be able to start the generator itself into operation, especially since the current supply will not be controlled. In addition, a three-level voltage regulator allows you to keep the current within a certain range.
Design
Even the simplest and homemade regulator should be able to optimally regulate the voltage, which is achieved as a result of the operation of the rotor. As a rule, in modern cars the rotor rotates to the right, but there are exceptions.
Any generator voltage regulator, even a homemade and simple one, will consist of the following components:
- Impeller. This component is mounted on the outside of the device. Its purpose is to blow and further cool the winding.
- The housing cover is designed to close access to the internal components of the device in order to protect the structure from dirt, dust and other debris. In addition, the lid can be additionally equipped with a casing. If there is a casing, the regulator itself will be installed behind it.
- Rectifier device. This circuit consists of several diodes. As a rule, there are six diodes. It should be noted that all diodes of the circuit are connected to each other via a so-called bridge.
- Rotor with winding. This component rotates around an axis, so the rotor must produce a magnetic field in the housing.
- The stator is another circuit component. On the stator housing there are three windings that are connected to each other. These circuit windings make it possible not only to supply a large amount of charge and power to the battery, but also to provide direct current to the entire on-board circuit of the machine.
- Directly relay. Thanks to an automotive relay, the circuit can maintain an optimal voltage level in the required range. The voltage should not be too high - it is always optimal (video author - Nikolay Purtov).
How much power in amperes should the car regulator produce after connection? The voltage generation circuit is carried out according to a certain principle. As a result of rotor rotation, the field winding is always exposed to a small voltage while the generator is connected to the battery. While rotation occurs, alternating current appears at the terminals and flows into the winding. The rotation of the rotor is ensured by the generator belt.
How much energy this device should produce is a secondary question, because when this energy is generated, first of all, a large voltage must be rectified. Diode bridges are used for this purpose. Since the voltage is high, the electronic voltage regulator comes into play. This component responds to changes in current that occur in the circuit, and then sends this information to a comparison device designed to analyze the required readings with those that were received. If the voltage at the generator terminals becomes lower, the regulator begins to increase the level of direct current in the circuit, raising it to the required level.
Principle of operation
If you connect a winding without a regulator to the power source, the DC level will be too high. Thanks to the relay in the diagram, this parameter is equalized to prevent equipment failure. The regulator itself is essentially a switch. If the current level increases to 13.-14 volts, the device automatically disconnects the winding from the network and turns it on if the current level is too low. As a result, the wiring is regularly switched at a high frequency; accordingly, the generator can produce a higher voltage (video author - Alex ZW).
Varieties
To connect to the vehicle's on-board circuit, there are several types of regulators designed to operate under direct current in amperes. It should be noted that some of them are characterized by certain malfunctions. But, as practice shows, in most cases, the malfunctions of these devices are usually identical to each other. Before we talk about how to check the DC voltage regulator in a car and how to identify faults, let’s pay attention to the types.
This way you can understand which type is better:
- Two-level type is obsolete, but our car enthusiasts continue to use it today. These regulators are based on an electromagnet that is connected to a winding sensor. Springs act as setting elements, and the function of a comparing component is performed by a movable lever. Its dimensions are quite small, and it is used to perform switching. The main drawback, which often leads to malfunction, is the device’s short lifespan.
- 40 Amp Electronic Devices are considered semiconductors. They are characterized by a long service life; accordingly, owners of cars with electronic regulators encounter malfunctions less often.
- Three-level designs in their structure they practically do not differ from those that we have already considered. The only fundamental difference is that such devices are equipped with additional resistance.
- Multi-level is another type. Some experts believe that such regulators are better than others, since they are equipped with three or even five additional resistances. In addition, there are models that can operate in tracking mode.
The cost of regulators may vary depending on the type and model. Which one is better to buy is entirely up to everyone. On average, the cost of such elements varies around $5. If your budget allows, it is better to purchase two regulators at once. Why is it better? Because this part is indispensable on the road.
Do-it-yourself diagnostics of the voltage regulator
How to check a car's voltage regulator to identify faults with your own hands? What is better to measure with your own hands - amperes or volts, which is better to use. To identify faults with your own hands, you need to use a multimeter or voltmeter. It is necessary that the device has a scale for measuring 15-30 volts. Do-it-yourself diagnostics of car relay faults at 40 amperes or lower using a multimeter should only be done with a charged battery.
- First you need to turn on the ignition.
- Start the engine yourself, let it run, while turning on the headlights. Let the engine run until the number of revolutions is about 2.5-3 thousand. As a rule, this requires waiting about 10 minutes.
- Using a voltmeter, measure the voltage at the battery terminals. The parameter should be about 14.1-14.3 volts.
If during diagnostics the indicators turn out to be lower or higher, it is better to purchase a new 40 amp relay. During diagnostics, the plugs should never be bridged, as this can lead to deformation and inoperability of the rectifier unit. To obtain more accurate readings, you need to make sure that the alternator belt is well tensioned.
Video “Diagnostics of the state of the regulator relay”
Find out how to check the malfunctions of this element yourself from the video below (the author of the video is Vyacheslav Chistov).
Sorry, there are no surveys available at this time.In electrical networks, automatic switching on and off of the generator is very often used. For this purpose there is a voltage regulator relay. With its help, the generator is protected from overloads and allows automatic regulation of voltage and current within established limits. This device is mainly used in the electrical networks of all cars and is installed in the engine compartment.
Purpose and design of the relay regulator
This device is a three-element one, consisting of three independent machines. These are a reverse current relay, a current limiter and a voltage regulator. These components are mounted on a common base and closed with a common lid. To connect wires, three terminals are installed on the base.
Automatic connection of the generator to the network is carried out using a reverse current relay, provided that it exceeds the battery voltage by a certain value. When the voltage drops, the generator automatically turns off. It consists of a coil and a core with two windings - shunt and serial with a different number of turns of wire, as well as a yoke and an armature with a contact system.
Preset generator voltage limits are maintained using a regulator. It includes a coil and a core with a winding, an armature with a contact system, a yoke, a magnetic shunt, and a cylindrical spring.
One end of the coil winding is connected to ground and the other to the generator terminal, passing through the yoke, resistance and windings. Thus, the value of current and magnetic flux depends on the voltage that develops. The voltage regulator allows you to automatically regulate the charging current obtained due to the voltage difference between the battery and the generator.
Using a Current Limiter
A current limiter is used to protect the generator from overloads. The composition includes a coil and a core with a winding, as well as a resistance winding, a yoke and an armature with contacts, as in other component devices. The principle of operation of the device coincides with the voltage regulator, when the entire generator load is passed through the limiter winding.
The general normal operation of the relay regulator can be determined using the button located on the instrument panel and by the condition of the battery itself. If the ammeter constantly shows a high charging current value, despite the fact that the battery is in good condition, this means that the voltage regulator relay is operating at high voltage.
This device is a rather complex device that requires precise adjustments and competent handling. Adjustment should only be carried out using precise control instruments.
Relay regulator voltage rectifier
When the voltage relay breaks down, problems arise in the operation of electrical equipment. There can be many reasons for a failure in the voltage regulator, but the most common of them is boiling off of the electrolyte in the battery. The voltage regulator (VR) cannot be repaired; it is simply replaced with a new one. However, before you change it, you need to make sure that it is the one that is faulty. You can check the generator relay regulator yourself.
In a car and in other vehicles, for the normal functioning of electrical equipment and other systems, a direct current of -13.5–14.5 V is required. If the voltage does not reach the norm or, on the contrary, exceeds it, electrical appliances will begin to fail, and the battery due to excess charge will shorten its service life. The relay-regulator acts as a stabilizer of this on-board voltage within specified limits, depending on the electrical load, generator rotor speed and ambient temperature. It passes the permissible voltage into the vehicle’s on-board network, thereby providing it with the required parameters.
Voltage regulator relay
Types of voltage relays and their design
To exaggerate, there are two types of devices and they both work on the same principle:
- individual or contact. Installed on the vehicle body under the hood using brackets. First, the wires come from the generator, and then go to the battery. This type is less common, as it was released about 30 years ago. There are also modified models that are just coming into use. Their key design elements are:
- Two resistance blocks;
- Magnetizing coil;
- Contact Group;
- Metal core.
- combined or electronic with brush assembly. Mounts directly onto the generator. Location of the relay in the housing with brushes.
What both have in common is that they have non-separable housings; often they are simply filled with sealants or special glue. Since they cannot be repaired, their prices are low. Previously, there was another type - combined with terminals, but it was not widely used, so it is not worth talking about them.
Old and new relay regulators
External signs of damage
Signs of a faulty relay may include:
- recharging the battery(there is not enough charge released or the electrolyte boils away);
- headlight brightness(changes during a breakdown, when the shaft speed is 2 thousand/min. The voltage level is higher than normal);
- burning smell inside the cabin.
Why does it break?
Today's relays are much more durable than their predecessors, but nothing is immune from failures. Factors such as:
- short circuit;
- moisture penetration(may happen while washing the car);
- mechanical damage;
- quality of the product itself(purchasing a device from unknown manufacturers does not guarantee long service life).
When the relay breaks down and recharging occurs, you need to diagnose the problem. There are two ways to check the generator voltage regulator - not removed from the car or filmed. Let's consider both options.
Checking the voltage without removing the relay regulator
How to check the regulator relay without removing it from the car?
It is easy to identify a “lack of charge” or “overcharge” of a battery. If there is a shortage, the car will not start, or after inserting the key, the motor will slowly start spinning, sometimes this is accompanied by the lights going out. When overcharging, the same symptoms will occur, only the reason will lie in boiling of the electrolyte. This can be understood by its quantity in the banks or by the white coating on the battery itself and around it. But you should make sure for sure by testing the on-board current using a multimeter, which you need to measure the voltage at the battery terminals while the engine is running. Note that the normal voltage may be 12.7V, but if it is lower, for example 12V, then there is a problem.
Very often the terminals themselves can be the culprit of the problem, as they can oxidize, so before checking it is necessary to remove any deposits and oxides on the terminals and contacts.
Stages of work:
- Start the engine and warm up for a few minutes.
- Connect the multimeter probes to the battery terminals, observing the polarity. Set the value on the device to 20 Volts.
- We look at the voltage when the low beam is on, at this time all other electrical consumers must be turned off. The shaft speed should be in the range of 1.5–2.5 thousand rpm. If voltage within 13.5–14.8V, this is normal, but if it exceeds, then the relay is unusable. In the case when the incoming current is less than 13.5V, then the cause of the failure may be either in the generator or in the wiring.
- Now we raise the load and evaluate at increased speeds to 2000–2500 thousand rpm. To do this, we turn on the high beams, heater, and windshield wipers. The voltage should not be less than 13.5V and more than 14.8V.
We told you how to check the generator voltage regulator with a multimeter; now we begin to check the combined relay-regulator circuit together with the brush assembly, since they are the most popular.
Checking the relay regulator
Testing the removed regulator (with circuit)
An electronic relay is most often mounted on the surface of the generator next to the generator shaft along which the brushes move, in the area of the generator armature slip rings. The entire combined unit is covered with a plastic cover. It is removed with a screwdriver, the shape of which can be either a cruciform or a hexagon.
Stages of work:
Using the same principle, you can check a separate type of regulator of a new type. To do this, you need to disconnect it from the body or cover of the generator and attach it to the circuit. Carry out the check in the same way. As for the old type of relay-regulator installed on kopecks, you need to check it a little differently. Their markings – “67” and “15”. The first contact “67” is a minus, and “15” is a plus. Otherwise the principle is the same.
