JPH036157Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a voltage regulating circuit used to stabilize the output voltage of a generator.

Generally, in a self-excited generator, as shown in FIG. 1, an excitation current I _f obtained from an excitation winding W1 is passed through an output transistor Q1 to a field winding W
3, while controlling the output voltage within a certain range by controlling the conduction of the output transistor Q1 based on the detection voltage Vd obtained from the detection winding W2 according to the output voltage of the generator. will be carried out. In this case, the output voltage of the excitation winding W1 is set high enough to ensure operation of the generator. On the other hand, the output voltage of the detection winding W2 is set to be relatively low because only the control signal necessary to control the conduction of the output transistor Q1 is obtained. Since the output currents of W1 and W2 of each winding are both alternating current, full-wave rectifiers RD1 and RD
2 and capacitors C1 and C2, respectively, before use. The rectified and smoothed excitation current I _f is guided to the collector of the output transistor Q1 via the field winding W3, and
A part of it is passed through a bias resistor Rb in series and is supplied as the base bias current Ib of the output transistor Q1. On the other hand, the rectified and smoothed pulsating waveform output voltage Vd is divided by resistors R1 and R2 and then applied to the base of the driver transistor Q2 via the Zener diode ZD. The collector side of this driver transistor Q2 is connected to the base of the output transistor Q1, and is connected to the output voltage Vd of the smoothed pulsating waveform and the Zener diode.
The ZD set voltage Vz is compared and the output voltage Vd is
When the transistor Q2 is made conductive in the area where Vz exceeds the set voltage Vz, the base bias current of the output transistor Q1 is bypassed and the output transistor Q1 becomes non-conductive. As a result, the excitation _current If is subjected to switching control (or continuously variable control) based on the output voltage Vd of the pulsating flow waveform, and the output voltage of the generator is feedback-controlled to be within a certain range.

Incidentally, in the conventional voltage regulating circuit as illustrated in FIG. 1, the base bias current Ib of the output transistor Q1 is supplied exclusively from the excitation winding W1 side. However, the excitation winding W
Since the output voltage of the transistor Q1 is set sufficiently high as described above, the voltage drop across the base bias resistor Rb of the output transistor Q1 becomes extremely large. Therefore, there arises a problem that the amount of heat generated in the bias resistor Rb increases and the power loss in this portion also becomes too large to be ignored. In this case, the bias current Ib is equal to the output transistor Q
In order to ensure operation 1, it cannot be made too small.

In addition to the main generator coil for general loads,
In a self-excited alternating current generator in which an auxiliary generator coil for field coil excitation is wound so as to be out of phase with the main generator coil by 90 degrees, the voltages generated in both the main and auxiliary generator coils are each subjected to full-wave rectification. A device has been developed in which the voltage is applied to an excitation circuit in which a field coil and a semiconductor switchgear are connected in series, and the semiconductor switchgear is controlled by a signal voltage from a voltage detection device that detects the voltage generated by the main generating coil. (Tokuko Showa 56-
(See Publication No. 28120). However, even with such a device, it is still not sufficient to reduce power loss.

This idea was made in view of the conventional problems mentioned above, and its purpose is to
In the voltage regulator circuit as described above, the base bias current of the output transistor can be reliably supplied, and the amount of heat generated and power loss in the base bias resistor can be reduced as much as possible, thereby increasing the efficiency of the generator. An object of the present invention is to provide a voltage regulating circuit that can be increased.

A preferred embodiment of this invention will be described below with reference to the drawings. Note that common or corresponding parts in each figure are indicated using the same reference numerals.

FIG. 2 shows an embodiment of the voltage regulating circuit according to this invention. The circuit shown in the figure is basically the same as the conventional example shown in FIG.

That is, while the excitation current I f obtained from the excitation winding W1 of the generator is supplied to the field winding W3 via the output transistor Q1, the excitation current I _f obtained from the excitation winding W1 of the generator is supplied to the field winding W3, while the excitation current I f obtained from the excitation winding W1 of the generator is supplied to the field winding W3 according to the output voltage of the generator from the detection winding W2 of the generator. The output voltage is adjusted within a certain range by controlling the conduction of the output transistor Q1 based on the detected voltage obtained.

Here, the difference from the conventional one is the bias circuit B of the output transistor Q1. This bias circuit B is configured to supply the base bias current Ib of the output transistor Q1 from the detection winding W2 side. As mentioned above, the output voltage of the detection winding W2 can be set significantly lower than the output voltage of the excitation winding W1.
The resistance value of the base bias resistor Rb1 for guiding a portion of the output current on the detection winding W2 side to the base of the output transistor Q1 can also be selected to be low, thereby making it possible to reduce the voltage drop across the resistor Rb1. Therefore, its bias resistance Rb1
In addition to reducing the amount of heat generated and the power loss in the generator, the efficiency of the generator can be increased by the amount of this loss reduction.

Particularly in the present invention, when the generator is started up, the field winding W3 is
A backup coil Wb is added for supplying an initial excitation current to the
The base bias current Ib of the output transistor Q1 is supplied through the output transistor Q1. The above-mentioned backup coil Wb is an output coil of a permanent magnet field type power generation system that is installed independently of the generator, and is only required to obtain a small amount of output voltage necessary for initial excitation of the generator. . Therefore, its output voltage is also the same as that of the detection winding W2.
It is set significantly lower than that of 1. Therefore, the heat generation and power loss in the base bias resistor Rb2 on the side of the backup coil Wb can also be significantly reduced.

As described above, the base of the output transistor Q1 is supplied with the currents Ib1 and Ib2 flowing through the two resistors Rb1 and Rb2 in a superimposed manner, thereby ensuring that the output transistor Q1 receives the bias current Ib necessary for operation. Obtainable. Particularly in the embodiment, a part of the bias current Ib is also supplied from the backup coil Wb side, thereby promoting conduction of the output transistor Q1 in the initial state when the generator starts up. ,
Thereby, the initial rise of the excitation current _If can be accelerated, and the rise characteristics of the generator can be improved.

As described above, the voltage regulating circuit according to this invention adjusts the output voltage of a generator that supplies the field current obtained by rectifying and smoothing the output voltage of the excitation winding to the field winding. Detected by a detection winding, rectified the output voltage of the detection winding by a rectifier, smoothed the rectified output by a smoothing capacitor, and compared the output voltage of the pulsating waveform with the set voltage,
The transistor is turned on or off depending on whether or not the output voltage exceeds the set voltage, and the output transistor connected to the transistor in Darlington controls the field current to be turned off or turned on. In a voltage regulating circuit configured to allow
A backup coil is added to supply initial excitation current to the field winding when the generator starts up, and the output current of the backup coil is supplied to the base of the output transistor through a resistor. Even with this additional configuration, the base bias current of the output transistor can be reliably supplied, and the amount of heat generated and power loss in the base bias resistor can be significantly reduced compared to conventional ones, which also improves the efficiency of the generator. can be increased.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an example of a conventional voltage regulating circuit, and FIG. 2 is a circuit diagram showing an embodiment of the voltage regulating circuit according to this invention. W1...excitation winding, W2...detection winding, W3...
...Field winding, Wb...Backup coil, RD
1 to RD3... Full wave rectifier, Q1... Output transistor, Rb, Rb1, Rb2... Base bias resistance, Ib... Bias current, If... Excitation current, B...
...bias circuit.

Claims (1)

[Scope of utility model registration request] Detecting the output voltage of the generator, which supplies the field current obtained by rectifying and smoothing the output voltage of the excitation winding W1 to the field winding W2.
The output voltage of the detection winding W2 is rectified by the rectifier RD2, and the output voltage of the pulsating waveform obtained by smoothing the rectified output by the smoothing capacitor C2 is compared with the set voltage. The transistor Q2 is turned on or off depending on whether or not the voltage exceeds the voltage range, and the output transistor Q1 connected to the transistor Q2 is connected to Darlington to switch on and off the field current. In the voltage regulation circuit, a backup coil Wb is used to supply the output current of the detection winding W2 to the base of the output transistor Q1 through the resistor Rb1, and to supply an initial excitation current to the field winding at the time of startup of the generator. , and the output current of the backup coil Wb is supplied to the base of the output transistor Q1 through the resistor Rb2.