JPH0428240Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is applied to a voltage regulator that adjusts the output voltage of an alternator to a predetermined value by controlling the opening and closing of the field current of the alternator. The present invention relates to an inspection device that shows whether the field control operation of a regulator is being performed normally.

Generally, a voltage regulator used in a device that rectifies the output voltage of an alternator for a vehicle driven by an internal combustion engine to charge a storage battery controls opening and closing of the field current of the alternator. The output voltage of this alternator is adjusted to a predetermined value. In order to check whether the field control operation of such a voltage regulator is being performed normally, conventionally, the waveform of the collector voltage of the transistor controlling the field is measured using an external device such as a synchroscope. The current situation is to monitor.

An object of the present invention is to provide a novel field control operation inspection device having an extremely simple configuration that can be incorporated into a voltage regulator without using an external device such as a synchroscope.

The invention will be described below with reference to illustrated embodiments.

Figure 1 shows a system using a voltage regulator VR to which the inspection device of the present invention can be applied.The output voltage of an alternator is applied to a storage battery B via a full-wave rectifier circuit D and a storage battery switch BS to charge this storage battery. This shows the general electrical circuit of the device. The alternator is driven by an internal combustion engine (not shown) and includes a three-phase star armature winding SC and a field winding FC.

In Figure 1, the voltage regulator VR continuously controls the field current to adjust the armature winding as follows.
Adjust the power generation pressure of SC, and thereby
It functions to keep the charging pressure applied to the battery constant.

The field winding FC is first excited by the storage battery B via the initial excitation resistor RF, and when the alternator starts rotating, the voltage generated in the armature winding SC is the same as that at both ends of the full-wave rectifier circuit D. appears in At the same time, the output voltage of the auxiliary rectifier circuit DS is increased by the voltage dividing resistor R ₃ ,
The reverse voltage of the Zener diode ZD applied to R ₄ and R ₅ and determined by this voltage dividing resistor is:
It is set in advance to be below the breakdown voltage. Therefore, in this state, the control transistor T ₂ is in a non-conducting state and in a conducting state with the main transistor T ₁ , so that the field current flows into the auxiliary rectifier circuit.
DS, field winding FC, continues to flow through the main transistor T ₁ .

Then, as the alternator speeds up and its output voltage increases, the reverse voltage of the Zener diode ZD exceeds the breakdown voltage, so the Zener diode ZD becomes conductive.
Therefore, the control transistor T ₂ becomes conductive, the main transistor T ₁ becomes non-conductive, and the field current is cut off.

In this way, the output voltage of the alternator is adjusted to a predetermined value by controlling the opening and closing of the field current by the main transistor _T1 . Furthermore, in Figure 1,
D ₁ is a diode for surge absorption, Th is a thermistor for temperature compensation, R ₁ is a bias resistor, R ₂ is a base resistor, C ₁ is a ripple absorption capacitor, C ₂ is a feedback capacitor, C ₃ is a surge absorption capacitors, are shown respectively.

FIG _. 2 is a specific electrical circuit diagram showing an embodiment of the field control operation testing device of the present invention. Connected. As shown,
The output terminal F of the voltage regulator VR is connected to a transistor for driving the display via a capacitor C and a resistor _R6 .
Connected to the base of T ₃ . A base resistor _R7 is connected in parallel with resistor _R6 . The collector of transistor T ₃ is a light-emitting diode, which acts as an indicator
The LED is connected to a voltage source +V via a bias resistor _R8 , and its emitter is grounded.

Figure 3 shows the voltage at output terminal F of voltage regulator VR.
_VF waveform diagram, and Figure 3a shows the voltage when the voltage regulator, that is, the main transistor _T1 , controls opening and closing of the field current when consuming current from storage battery B (light load). This is a waveform diagram, which is a kind of pulsating alternating current waveform. On the other hand, Fig. 3b
is a voltage waveform diagram when the main transistor _T1 fails in an open state or when a circuit failure occurs such that the main transistor T1 does not operate normally.
FIG. 2 is a voltage waveform diagram when T ₁ fails due to short circuit or when a circuit failure occurs.

Therefore, in FIG. 2, since the terminal F and the base of the main transistor _T1 are AC-coupled by the capacitor C, the driving transistor is activated at the lowest frequency of the switching operation frequency of the main transistor _T1 .
By setting the circuit constants so that _T3 operates, as long as a voltage with a waveform as shown in Figure 3a is applied to the terminal F, in other words, the field control operation of the voltage regulator VR As long as this is performed normally, the light emitting diode LED will emit light and this state can be recognized.

As mentioned above, according to the present invention, it is possible to monitor the operation of a voltage regulator with an extremely simple and low-cost configuration, and since it has a non-contact configuration, it is earthquake resistant and can be used as a device for vehicles. Optimal.
In the illustrated embodiment, a light emitting diode is used as the indicator, but it goes without saying that a buzzer, lamp, etc. can also be used.

Transistor _T3 in FIG. 2 can be frequency-divided by an IC having a counter function and used for lamp display.

Furthermore, although the present invention has been described as being incorporated into an on-vehicle charging device, because of its simple configuration, it can also be incorporated into an on-vehicle alternator-related tester; checker, etc.

[Brief explanation of the drawing]

FIG. 1 shows an electric circuit of a device for charging an on-vehicle storage battery to which the present invention can be applied. FIG. 2 is an electrical circuit diagram showing one embodiment of the present invention. Figures 3a to 3c represent the voltage regulators shown in Figures 1 and 2.
It is a voltage waveform diagram at terminal F of VR. Symbol explanation, VR...Voltage regulator, B...Storage battery, D...Full wave rectifier circuit, FC...Field winding, SC
... Armature winding, ZD ... Zener diode,
_T1 ...Main transistor, _T2 ...Control transistor, _T3 ...Drive transistor, C...Capacitor, LED...Light emitting diode.

Claims (1)

[Scope of utility model registration request] A field current switching control element T ₁ provided in a voltage regulator VR that adjusts the output voltage of the alternator to a predetermined value by controlling switching of the field current of the vehicle alternator SC. and a field control operation inspection device connected to a connection point F with the field winding FC of the alternator, a capacitor C connected to the connection point, and the switching control element connected to the capacitor. a drive control element that inputs an AC signal having a switching operation frequency of the switching control element applied to the connection point from the capacitor through the capacitor;
1. A field control operation inspection device comprising: T ₃ and an indicator LED connected to the drive control element and driven by the drive control element when the alternating current signal is input.