JPH036160Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a voltage regulator for a self-excited alternating current generator, and its purpose is to provide a device that is extremely simple in construction, inexpensive, and capable of supplying a stable constant voltage output. It is. Another object is to provide an apparatus capable of highly accurate control over load fluctuations or temperature changes. The present invention will be explained in detail below using the drawings. Figures 1 and 2 are circuit diagrams of one embodiment of the present invention and operation waveform diagrams of each part thereof. In the figures, MC is the armature winding of a self-excited alternator;
FC is the field winding, L is the load, SW is the power switch,
SCR is a thyristor that controls the field current of the field winding FC, _D2 is a flywheel diode, SC is a phase control circuit that forms the main part of the present invention, and DZ is a thyristor that controls the field current of the field winding FC. _D1 and _{R1 R2} are diodes and voltage dividing resistors for detecting the output voltage during the other half cycle of _the AC output (terminal'); C is a capacitor that is charged to the output detection voltage through the constant voltage diode DZ during the other half cycle of the AC output, and is discharged through the voltage dividing resistor _R2 during the other half cycle of the AC output. The dividing point b of the voltage dividing resistor R ₁ R ₂ is connected to the gate pole G of the thyristor SCR, and a gate circuit is formed which turns on the gate G of the thyristor SCR when the voltage difference between the reference voltage and the discharge voltage of the capacitor C is applied. is forming. The circuit of the present invention is configured as described above. Next, the operation will be explained with reference to FIG. First, when a generator is driven by an engine or the like, an electromotive force (several volts) is generated in the armature winding MC due to the residual magnetism of the iron core. When this electromotive force is a positive half cycle (terminal) armature winding MC - resistance
A gate trigger current flows through the path R ₃ - resistor R ₂ - gate G of thyristor SCR, cathode K - armature winding MC', and thyristor SCR becomes conductive. Next, a field current flows through the path of armature winding MC - field winding FC - thyristor SCR - armature winding MC, the armature winding voltage increases, and the difference between the armature winding voltage and field current increases. Due to the mutual effect, the generator generates a predetermined AC output voltage and performs normal operation. The operation during normal operation will be explained below. Figure 2 is a diagram of the operation waveforms of each part based on GND in Figure 1. A is the output voltage (terminal -') waveform of the generator, B is the output detection voltage waveform (terminal), and C is the reference voltage waveform (terminal). D shows the voltage waveform of the thyristor SCR (terminal -K). First, during the negative half cycle (terminal ') of the output voltage (Fig. 2 A), the armature winding MC
'Constant voltage diode DZ <Resistance R ₂ Capacitor> C ₁ - Resistor R ₁ - Diode D ₁ - A current flows through the armature winding path, and at the same time generates the output detection voltage shown in Figure 2 B at the terminal point. This detected voltage charges the capacitor C to the polarity shown, and the capacitor C maintains this charged charge. Note that the charging voltage of the capacitor C is proportional to the voltage dividing ratio of the voltage dividing resistor R ₁ R ₂ and a change in the power supply voltage. Then, during the positive half cycle (terminal) of the output voltage, the armature winding
A current flows through the path of MC - resistor R ₃ - constant voltage diode DZ - armature winding', and a reference voltage shown in FIG. 2C is generated at the terminal. Therefore, during the positive half cycle, the potential of the terminal becomes the difference between the reference voltage and the charging voltage of the capacitor C charged during the negative half cycle with respect to GND. On the other hand, since the charge in the capacitor C gradually discharges due to the time constant with the resistor _R2 , the operating waveform becomes an upward-sloping waveform as shown in Figure 2B, and the thyristor SCR
The gate voltage of is gradually increased. And when this voltage reaches the firing voltage of the thyristor SCR (time
t ₁ ) Thyristor SCR is terminal - resistor R ₃ - resistor R ₂
-Gate current flows through the path of thyristor gate G and cathode K-terminal', turning on the thyristor SCR.
urge As a result, as described above, a field current flows through the field winding FC, increasing the output voltage. According to the present invention, the capacitor C is charged in accordance with the voltage value during the negative half cycle of the AC output voltage to maintain (memorize) the charge corresponding to the output detection voltage, and the capacitor C is charged during the positive half cycle. It is configured so that the charge is discharged via resistor _R2 with a constant time constant, and at the same time it is directly compared with the reference voltage of the voltage regulator diode, and a gate signal is given when the difference voltage reaches the gate voltage VGt of the thyristor. be. Therefore, when the output voltage decreases (dotted line in Figure 2), the charging voltage of capacitor C also decreases in proportion to this, so the operating waveform changes during the positive half cycle of AC output as shown by the dotted line in Figure 2. As a result, the voltage difference between the reference voltage and the discharge voltage reaches the gate voltage of the thyristor SCR earlier (time t ₂ ), and the firing phase advances.
The conduction angle of the SCR becomes wider, the excitation current increases, and the output voltage increases. On the other hand, when the output voltage increases, the charging voltage of capacitor C also increases, but the discharge time constant during the next cycle is constant, so the voltage across resistor _R2 , that is, the difference voltage from the reference voltage, is the voltage difference between the thyristor SCR
The time when the gate voltage is reached is delayed, the ignition phase is delayed, and the conduction angle of the thyristor SCR is narrowed. Through these phase controls, the output AC voltage is controlled to a substantially constant value. Fig. 3 is a circuit diagram of another embodiment of the present invention, and the difference from Fig. 1 is that a diode _D1 of the phase control circuit and a resistor _{R4 and a thermistor S are installed at one end of the series circuit of voltage dividing resistors R1 and R2} . A temperature compensation circuit TC consisting of the following components is provided. With this configuration, since the temperature compensation circuit is inserted into the capacitor charging circuit, it is possible to achieve high output voltage detection accuracy and highly accurate phase control regardless of temperature fluctuations.
In FIG. 3, _R5 is a gate resistance D, and R5 is a diode for preventing wraparound.

As is clear from the above description, according to the present invention, it is possible to provide a device that can provide a stable constant voltage output with a simple configuration, and therefore has great practical effects.

[Brief explanation of the drawing]

1 and 2 are circuit diagrams of one embodiment of the present invention and operation waveform diagrams of each part thereof, and FIG. 3 is a circuit diagram of another embodiment of the present invention. In the figure, L is the load, SW is the power switch, MC is the armature winding, FC is the field winding, SCR is the thyristor, SC is the phase control circuit, DZ
is a constant voltage diode, C is a capacitor, R ₁ , R ₂
is a voltage dividing resistor, LC is a lamp coil, REC is a rectifier,
TC is a temperature compensation circuit, and S is a thermistor.

Claims (1)

[Scope of utility model registration request] 1. A self-excited alternator having an armature winding MC and a field winding FC, a thyristor SCR that controls the field winding current, and a firing phase of the thyristor that is controlled according to the output voltage of the generator. In a voltage regulator for a self-excited alternator equipped with a phase control circuit SC, the phase control circuit SC includes a diode D1.
a circuit in which a resistor R ₃ is connected in parallel to a series body of voltage dividing resistors R ₄ and R ₂ for voltage detection; a constant voltage diode DZ connected in series to the circuit with the same polarity as the diode D ₁ ; A series body of a temperature sensing element S and a capacitor C connected to both ends of the resistors R ₄ and R ₂ , a dividing point of the voltage dividing resistor and a connection point of the temperature sensing element S and the capacitor C are respectively connected to the gate of the thyristor. a voltage difference between a reference voltage generated by the constant voltage diode during one half cycle of the output voltage and a voltage of the capacitor that is charged during the other half cycle and discharged during the one half cycle; A voltage regulator for a self-excited alternating current generator, characterized in that a voltage is generated at a voltage dividing point of the voltage detecting voltage dividing resistor, and thereby the thyristor is controlled via the gate circuit.