JPH089696A - Power generator - Google Patents

Abstract

(57) [Abstract] [Purpose] The output of the generator 1 is suppressed by suppressing the output increase of the generator 1 when the temperature of the exciting coil 2 is low and suppressing the heat generation of the element that detects the output increase of the generator 1. The heat generation of the exciting current control circuit 7 for controlling is suppressed. [Structure] The exciting coil 2 includes a return circuit 9 for supplying a return current when a switching means 12 for energizing and interrupting the exciting coil 2 is turned off. In this reflux circuit 9,
When the return current detecting element 23 for detecting the return current is provided and the switching means 12 is off and the detected current of the return current detecting element 23 exceeds a predetermined value, the switching element 12 is turned off. keep. When the temperature of the exciting coil 2 rises, the output of the generator 1 decreases and the proportion of current flowing through the return circuit 9 (reflux current detecting element 23) decreases. As a result, heat generation by the return current detecting element 23 for suppressing the increase in the output of the generator 1 when the temperature of the exciting coil 2 is low is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generator which controls the exciting current by intermittently energizing an exciting coil of a generator to control an exciting current.

[0002]

2. Description of the Related Art For example, in a generator for a vehicle, when the temperature of the exciting coil is low immediately after starting the engine, the resistance value of the exciting coil is low. When the resistance value of the exciting coil is low, the exciting current increases, the power generation output increases, and the driving load of the generator increases. Immediately after starting the engine, when the engine is cold, the generated torque of the engine is unstable. Therefore, if the driving load of the generator is large, the rotation of the engine becomes unstable.

As a conventional technique for solving this problem,
The technique disclosed in JP-A-62-104500 is known. As shown in the electric circuit of FIG. 6, this technique uses the switching means 1 in the energizing circuit on the negative potential side of the exciting coil.
01, the switching means 101 is turned on and off.
A circuit for energizing and deenergizing the exciting coil under control is provided. Further, a current value detecting resistor 102 for detecting the value of the exciting current is provided in the energizing circuit of the switching means 101, and it is determined that the exciting current detected by the current value detecting resistor 102 exceeds the set value. When the exciting current exceeds the set value by this comparator 103, the control transistor 104 is turned on to turn on the switching means 101.
It is equipped with a circuit that turns off and stops the excitation coil energization. The energization stop time of the exciting coil by this circuit is set by the discharge time of the capacitor 105, and when the discharge of the capacitor 105 is completed, the switching means 101 is restarted.
Is turned on, energization of the exciting coil is started, and the above is repeated. This technique limits the maximum value of the exciting current to a constant value even if the temperature of the exciting coil changes. For this reason,
It is possible to suppress an increase in the output current of the generator at low temperatures, and to suppress the drive load of the generator on the engine immediately after the engine is started.

[0004]

When the generator operates and the temperature of the exciting coil rises, the resistance value of the exciting coil increases and the exciting current decreases. Then, the current value detected by the current value detecting resistor 102 becomes small, and the comparator 103 and the control transistor 104 do not turn off the switching means 101. On the other hand, when the temperature of the exciting coil rises and the exciting current decreases, the power generation output decreases, so the power generation demand of the generator also increases. As a result, the switching means 101 is turned on, and the time for energizing the exciting coil becomes longer. While the exciting coil is energized, the exciting current always flows through the current value detecting resistor 102. Therefore, in addition to heat generation due to current loss of the switching means 101, heat due to current loss of the current value detection resistor 102 is generated. This allows the circuit that controls the output of the generator to
Heat can cause defects. For this reason, there is a problem that the circuit for controlling the output of the generator needs cooling measures such as increasing cooling air.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to suppress the increase in the output of the generator when the temperature of the exciting coil is low and to control the output of the generator. It is to provide a power generation device capable of suppressing heat generation.

[0006]

The power generation device of the present invention employs the following technical means. [Means for Claim 1] A generator comprises an exciting coil for generating a magnetic field, and a generator equipped with an armature coil for rotating relative to the exciting coil to generate electric power, and energization of the exciting coil. And a cut-off means for controlling the excitation current by controlling the switching means, and an exciting current control circuit for controlling the exciting current by the switching means, when the energization of the exciting coil is cut off by the switching means, a return current to the exciting coil And a reflux circuit. The excitation current control circuit includes a return current detection element that detects a return current value in the return circuit, and the return current detection element detects when the switching means cuts off energization of the excitation coil. The switching means is provided with a power generation suppressing means for interrupting the energization of the exciting coil while the value of the circulating current exceeds a predetermined value.

[Means of Claim 2] In the power generator of Claim 1, the power generation suppressing means has a signal generating means that oscillates at a predetermined cycle to generate an exciting coil cutoff signal. The energization of the exciting coil is cut off based on the generated exciting coil cutoff signal. The cycle of the cutoff signal generated by the signal generating means is preferably sufficiently smaller than the time constant of the exciting coil.

[Means of claim 3] In the power generator of claim 1, the power generation suppressing means has a signal generating means for generating an exciting coil cutoff signal after a predetermined time has passed since the energization of the exciting coil was started. Then, the energization of the exciting coil is cut off based on the exciting coil cutoff signal generated by the signal generating means. It is desirable that the predetermined time from the start of energization of the exciting coil to the generation of the exciting coil cutoff signal by the signal generating means is sufficiently smaller than the time constant of the exciting coil.

[Means of Claim 4] In the power generator of claim 2 or claim 3, the signal generating means has signal stopping means for stopping the generation of the exciting coil cutoff signal at a predetermined temperature or higher.

[Means of Claim 5] In the power generator according to any one of Claims 1 to 4, in the exciting current control circuit, the switching means is provided on the positive potential side of the exciting coil. In the high-side power save circuit, the return circuit including the return current detection element is provided on the negative potential side of the switching means.

[0011]

[Operation and effect of the invention] [Operation of claim 1] When the exciting current control circuit stops the energization of the exciting coil by the switching means, a return current is generated in the return circuit. This return current value depends on the energization amount of the exciting coil when the energization of the exciting coil is cut off.
That is, when the temperature of the exciting coil is low and the resistance value of the exciting coil is low, the initial value of the return current value is large. On the contrary, when the temperature of the exciting coil is high and the resistance value of the exciting coil is large, the initial value of the return current value is small. Then, the return current value generated when the energization of the exciting coil is stopped is gradually attenuated.

This return current value is detected by a return current detecting element provided in the return circuit. The energization of the exciting coil is cut off, and the exciting current control circuit continues to cut off the energization of the exciting coil while the value of the circulating current detected by the circulating current detecting element exceeds a predetermined value. That is, when the temperature of the exciting coil is low and the initial value of the return current value is large,
The shutoff time of the exciting coil becomes longer. Then, when the return current value detected by the return current detection element falls below a predetermined value and there is a power generation request of the generator, energization of the exciting coil is started.

With the above operation, when the temperature of the exciting coil is low, the time for which the return current value exceeds the predetermined value becomes long, and the time for which the exciting coil is de-energized by the switching means becomes long. On the contrary, when the temperature of the exciting coil rises, the time during which the return current value exceeds the predetermined value decreases or disappears, and the time during which the exciting coil is de-energized by the switching means becomes short.

As the temperature of the exciting coil rises and the resistance value of the exciting coil increases, the time during which the exciting coil is energized becomes longer. As a result, the rate at which the return current flows through the return circuit decreases. That is, the ratio of the current flowing through the return current detecting element provided in the return circuit is reduced, and the heat generation of the return current detecting element is suppressed.

[Effect of claim 1] The power generation device of the present invention,
As shown by the above operation, in a normal state where the temperature of the exciting coil is high, the ratio of the return current flowing through the return circuit is reduced, and the heat generation of the return current detection element is suppressed. For this reason,
The heat generation amount of the exciting current control circuit that controls the output of the generator is
By being suppressed to be much smaller than the conventional one, it is possible to reduce the possibility that the exciting current control circuit will malfunction due to heat. Further, since the cooling measures for cooling the heat of the exciting current control circuit can be reduced or eliminated, the cost can be suppressed and the restriction on the position where the exciting current control circuit is mounted can be reduced.

[Operation of Claim 2 and Effect of the Invention] When the signal generating means receives the exciting coil cutoff signal generated at a predetermined cycle, the power generation suppressing means cuts off the energization of the exciting coil by the switching means. In this way, since the energization of the exciting coil is surely cut off at a predetermined cycle, it is possible to reliably prevent the output of the generator from significantly increasing when the temperature of the exciting coil is low.

[Operation of Claim 3 and Effect of the Invention] The signal generating means generates an exciting coil cutoff signal after a predetermined time has passed since the energization of the exciting coil was started. When receiving the exciting coil cutoff signal generated by the signal generating means, the power generation suppressing means cuts off the energization of the exciting coil by the switching means. In this way, the excitation coil is de-energized a predetermined time after the energization of the excitation coil is started, so that the maximum output of the generator is kept substantially constant when the excitation coil is repeatedly energized and interrupted. Be done. That is, the maximum output value of the generator is stable.

[Operation of Claim 4 and Effect of the Invention] The temperature of the exciting coil rises due to the operation of the generator, and the temperature of the exciting current control circuit also rises due to the heat generation of each component. When the temperature of the exciting coil or the temperature of the exciting current control circuit reaches or exceeds a predetermined temperature, the signal generating means
Stop the excitation coil cutoff signal. When the temperature of the exciting coil rises, the resistance value of the exciting coil increases and the generated output of the generator decreases. Then, by stopping the generation of the exciting coil cutoff signal by the signal generating means, it is possible to energize the exciting coil according to the output request of the generator. That is, when the temperature of the exciting coil rises, it becomes possible to constantly energize the exciting coil.

[Operation of Claim 5 and Effect of Invention] First, for comparison, the present invention is applied to an exciting current control circuit of a low side power save circuit in which a switching means is provided on the negative potential side of an exciting coil. The voltage applied to the return current detecting element cannot be directly output to the comparator or the D / A converter, and a circuit for voltage drop is required. Therefore, the present invention is applied to an exciting current control circuit that employs a high side power save circuit in which the switching means is provided on the positive potential side of the exciting coil, so that the voltage applied to the return current detecting element is directly compared with the comparator. And D
It can be output to the A / A converter, and the circuit configuration can be simplified.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a power generator of the present invention will be described based on an embodiment shown in the drawings. [Structure of Embodiment] FIGS. 1 to 3 show an embodiment of the present invention, and FIG. 1 is an electric circuit diagram showing the structure of a power generator installed in an automobile. The generator 1 includes an exciting coil 2 that generates a magnetic field when energized, and an armature coil 3 that generates electric power by relatively rotating in a magnetic field generated by the exciting coil 2. One of the child coils 3 is driven by an engine (not shown). The alternating current generated by the armature coil 3 is converted into direct current by the rectifier circuit 4 and output to the battery 5 and each electric load 6 of the vehicle.

The power generation by the generator 1 is requested according to the voltage of the battery 5, that is, the usage of each electric load 6. The power generation amount of the generator 1 is controlled by energization and interruption of the excitation coil 2, and energization and interruption of the excitation coil 2 are controlled by the excitation current control circuit 7.
The excitation coil 2 is connected to a return circuit 9 including a flywheel diode 8 that causes a return current to flow through the excitation coil 2 due to the inductance component of the excitation coil 2 when the excitation coil 2 is cut off from the energized state. ing.

The exciting current control circuit 7 includes a switching means 12 (power transistor) for energizing and de-energizing the exciting coil 2 in the energizing path for energizing the exciting coil 2 from the battery 5 via the ignition key switch 11. Prepare This switching means 12 is connected to the positive potential side of the exciting coil 2, that is, to the battery 5 rather than the exciting coil 2.
The negative potential side of the exciting coil 2 together with the negative potential side of the rectifier circuit 4 and the negative potential side of the return circuit 9,
Grounded to the vehicle.

The exciting current control circuit 7 turns on the switching means 12 when the voltage of the battery 5 drops to a predetermined voltage.
In addition to the power generation requesting means 13 for energizing the exciting coil 2 to operate the generator 1, the power generation suppressing means 14 for suppressing the exciting current when the temperature of the exciting coil 2 is low such as immediately after the engine is started.

The power generation requesting means 13 comprises a pre-stage transistor 17 for turning on the switching means 12 by the voltage inputted through the ignition key switch 11, the first and second resistors 15 and 16. Also, the power generation requesting means 1
3 is an ignition key switch 11 and a first resistor 1
A first Zener diode 18 is provided for converting the battery voltage VB input via 5 to the first reference voltage V1. Furthermore, the power generation requesting means 13 uses the second reference voltage V1 to set the second and third resistors 19 and 20 to the second reference voltage V1.
Reference voltage V2 (voltage for determining whether the voltage of the battery 5 is equal to or higher than a predetermined voltage) and battery voltage (rectifier circuit 4
Output voltage) VB detection voltage Vb, and generates a Hi signal when the detection voltage Vb of the battery voltage VB is higher than the second reference voltage V2; And a first transistor 22 for turning off 17 and turning off the switching means 12.

The power generation requesting means 13 adopts the above circuit configuration to detect the detected voltage Vb of the battery voltage VB.
Is lower than the predetermined voltage, the front-stage transistor 17
To turn on the switching means 12 to turn on the excitation coil 2
Is energized to operate the generator 1. When the detected voltage Vb of the battery voltage VB is higher than the predetermined voltage, the first comparator 21 turns on the first transistor 22 and turns off the front stage transistor 17. Then, the switching means 12 also
When turned off, the excitation coil 2 is de-energized and the generator 1 stops operating.

The power generation suppressing means 14 is a return current detecting element 23 (resistor) for detecting a return current value flowing through the return circuit 9.
The switching means 12 is turned off and the exciting coil 2 is provided.
When the energization of the device is cut off, the return current detecting element 23
Is a circuit for turning off the switching means 12 while the value of the reflux current detected by is exceeding a predetermined value. In particular,
The voltage value Vi detected by the return current detecting element 23 and the second value
Zener diode 24 to fifth and sixth resistors 25, 2
Third reference voltage V3 set by 6 (voltage for judging whether or not the return current value exceeds a predetermined value)
And a second comparator 27 that generates a Hi signal when the detected voltage Vi detected by the return current detection element 23 is higher than the third reference voltage V3, and the preceding transistor 17 is turned off by this Hi signal. And a second transistor 28 for turning off the switching means 12.

Further, the power generation suppressing means 14 generates a short Hi signal (hereinafter referred to as an exciting coil cutoff signal) at a predetermined cycle, turns on the second transistor 28, and turns off the switching means 12.
A signal generating means 29 is provided for cutting off the energization of the exciting coil 2 at a predetermined cycle by turning on F. The cycle of the cutoff signal generated by the signal generating means 29 is set sufficiently smaller than the time constant of the exciting coil 2, and when the exciting coil 2 is energized, before the exciting current of the exciting coil 2 becomes extremely large. The exciting coil cutoff signal is output again to cut off the energization of the exciting coil 2.

The electric circuit of the signal generating means 29 is shown in FIG. The signal generating means 29 charges the first reference voltage V1 via the seventh resistor 30 to the charging voltage Vc of the capacitor 31.
From the first reference voltage V1 to the eighth and ninth resistors 32, 33
When the capacitor charging voltage Vc is higher than the fourth reference voltage V4, the Hi signal (this Hi signal is used as the above-described exciting coil cutoff signal to cause the second transistor 28 to And a fourth reference voltage V4 applied to the negative input of the third comparator 34 when the third comparator 34 generates a Hi signal. A third transistor 35 for reducing the voltage to V5 and a fourth transistor 36 for discharging the capacitor 31 when the third comparator 34 generates a Hi signal are provided.

The operation of the signal generating means 29 will be described with reference to the time chart of FIG. The capacitor 31 is charged by the current applied through the seventh resistor 30,
The capacitor charging voltage Vc increases and the fourth reference voltage V4
When it reaches, the third comparator 34 generates a Hi signal (excitation coil cutoff signal). When the third comparator 34 generates a Hi signal, the third transistor 35 is turned on, the voltage of the negative input of the third comparator 34 is reduced to the fifth reference voltage V5, and the fourth transistor 36 is turned on and the capacitor is turned on. 31 is discharged,
The capacitor charging voltage Vc drops. When the capacitor charging voltage Vc drops to the fifth reference voltage V5, the third comparator 3
The output of 4 is inverted to the Low signal. Then, the third and fourth transistors 35 and 36 are turned off to stop the discharge of the capacitor 31, and the voltage of the negative input of the third comparator 34 rises to the fourth reference voltage V4. Then, again, the capacitor 31 is charged by the current applied through the seventh resistor 30, and the above is repeated. By repeating the above,
As shown by the solid line A in FIG. 3, the signal generating means 29 generates an exciting coil cutoff signal at a predetermined cycle with a short interval.

Further, the signal generating means 29 of this embodiment incorporated in the exciting current control circuit 7 has a predetermined temperature (for example, 90 ° C.).
A signal stopping means 37 for stopping the generation of the exciting coil cutoff signal when the temperature rises above 0 ° C) is mounted. The signal stopping means 37 adjusts the fifth transistor 38, the operating point of which changes depending on the temperature, and the tenth and eleventh transistors which are turned on when the fifth transistor 38 reaches a predetermined temperature.
The resistors 39 and 40 are provided. When the temperature rises above a predetermined temperature and the fifth transistor 38 turns on, the positive input (capacitor charging voltage Vc) of the third comparator 34 is lowered via the diode 41, and the output of the third comparator 34 becomes Low. To be held by.

[Operation of the Embodiment] Next, the operation of the embodiment will be briefly described with reference to the time chart shown in FIG. In this operation, the battery voltage is lower than the predetermined voltage, and the first transistor 22 of the power generation requesting unit 13 is OF
Then, the ignition key switch 11, the first and second resistors 15 and 16 are provided at the base of the front-stage transistor 17.
A state in which a voltage is applied via the power generation requesting means 13
Indicates a state in which energization of the exciting coil 2 is required).

When the temperature of the exciting coil 2 is low immediately after the engine is started, the amount of heat generated by the exciting current control circuit 7 is small and the temperature inside the exciting current control circuit 7 is also low. Then, until the fifth transistor 38 of the signal generating means 29 incorporated in the exciting current control circuit 7 reaches a predetermined temperature, as shown by the solid line A in FIG. A shutoff signal is generated.

When the exciting coil cutoff signal is generated from the signal generating means 29 at time t1, the second transistor 28 is turned on.
Then, the front stage transistor 17 and the switching means 12 are OF
Then, the excitation coil 2 is de-energized. Then, due to the inductance component of the exciting coil 2,
A return current that circulates in the return circuit 9 flows. This return current has a higher rate of increasing as the temperature of the exciting coil 2 is lower and the resistance value of the exciting coil 2 is lower. This return current value is the return current detection element 23 provided in the return circuit 9.
Detected by. When the voltage value Vi detected by the return current detecting element 23 is higher than the third reference voltage V3, the second comparator 27 keeps the second transistor 28 ON. That is, when the voltage value Vi detected by the return current detecting element 23 is higher than the third reference voltage V3,
The front stage transistor 17 and switching means 12 are OFF
Then, the energization of the exciting coil 2 is maintained in the stopped state.
The energization stop time of the exciting coil 2 becomes longer as the temperature of the exciting coil 2 is lower and the resistance value of the exciting coil 2 is lower, because the circulating current is larger.

When the voltage value Vi detected by the return current detecting element 23 gradually decreases and becomes lower than the third reference voltage V3 (time t2), the output of the second comparator 27 is inverted to Low,
The second transistor 28 is turned off. Then, the pre-stage transistor 17 and the switching means 12 are turned on, and the energization of the exciting coil 2 is started. In this state, when the exciting coil cut-off signal is generated again from the signal generating means 29 (at time t3), the second transistor 28 is turned on, the pre-stage transistor 17 and the switching means 12 are turned off, and the exciting coil 2 is turned on.
The energization is stopped and the above operation is repeated.

After the engine is started for a while, the temperature of the exciting coil 2 rises, and the temperature inside the exciting current control circuit 7 rises due to the heat generated by each component. Then, when the fifth transistor 38 of the signal generating means 29 built in the exciting current control circuit 7 rises to a predetermined temperature, the signal generating means 29 does not generate the exciting coil cutoff signal. Therefore, the exciting current control circuit 7 controls the switching means 12 only by the operation of the power generation requesting means 13 to control the output of the generator 1.

[Effects of the Embodiment] In the present embodiment, the return current detecting element 23 provided for suppressing the output of the generator 1 when the temperature of the exciting coil 2 is low includes the battery 5, the ignition key switch 11, and the switching. Not in the energizing path for energizing the exciting coil 2 via the means 12,
It is provided in the reflux circuit 9. Then, during normal operation when the temperature of the exciting coil 2 is high and the output of the generator 1 is reduced,
The rate at which the return current flows through the return circuit 9 decreases. As a result, during normal operation of the generator 1, the return current detection element 2
The heat generation of 3 is suppressed. Therefore, the exciting current control circuit 7
The amount of heat generation is suppressed to a much smaller value than in the conventional case, and the possibility that the exciting current control circuit 7 will be defective due to heat is reduced. Further, since the heat generated by the exciting current control circuit 7 is reduced, it is possible to suppress the cooling measures for cooling the exciting current control circuit 7. As a result, the cost for installing the power generator can be suppressed, and the restriction on the position where the exciting current control circuit 7 is installed can be reduced.

In the present embodiment, the exciting current control circuit 7 is provided with the signal generating means 29 for generating the exciting coil cutoff signal at a predetermined short cycle, so that when the temperature of the exciting coil 2 is low, Since the energization is reliably cut off in a short cycle, it is possible to reliably prevent the output of the generator 1 from significantly increasing. When the temperature of the exciting current control circuit 7 rises above a predetermined temperature, the signal generating means 29 stops the generation of the exciting coil cutoff signal. Therefore, when the temperature of the exciting coil 2 rises, the generator 1 by the power generation request means 13 is generated. It is possible to energize the exciting coil 2 only by the power generation request.
That is, when the temperature of the exciting coil 2 rises, the exciting coil cutoff signal is not generated, so that the exciting coil 2 can be constantly energized.

In the present embodiment, since the switching means 12 is provided on the positive potential side of the exciting coil 2, the return current detection element 23 is provided on the negative potential side of the switching means 12 and the return current detection element 23 returns the return current. The detection error of can be reduced. Further, since the return current detection element 23 is provided on the negative potential side of the switching means 12, the voltage value Vi detected by the return current detection element 23 is directly output to the second comparator 27. As a result, the circuit configuration of the exciting current control circuit 7 can be simplified.

[Second Embodiment] FIGS. 4 and 5 show a second embodiment. FIG. 4 is an electric circuit diagram of the signal generating means 29, and FIG. 5 is an operation of the signal generating means 29 and a second comparator. Two
7 is a time chart showing the operation of No. 7. Although the signal generating means 29 of the first embodiment has shown an example in which the exciting coil cutoff signal is generated at a predetermined cycle, the signal generating means 29 of the present embodiment.
Is for generating an exciting coil cutoff signal after a predetermined time has passed since the energization of the exciting coil 2 (see the first embodiment), and the signal generating means 29 is excited after the energization of the exciting coil 2 is started. The predetermined time until the coil cutoff signal is generated is set sufficiently smaller than the time constant of the exciting coil 2.

The signal generating means 29 of this embodiment is
When the switching means 12 (see the first embodiment) is OFF, the fact that the voltage of the connection terminal (F terminal) on the positive potential side of the exciting coil 2 is lowered is utilized to utilize the capacitor 3
The positive potential side of No. 1 and the F terminal are connected via the twelfth resistor 42 and the diode 43. by this,
Since the signal generating means 29 starts charging the capacitor 31 after the switching means 12 is turned on, the signal generating means 29 is set to the third time after a predetermined time has passed since the energization of the exciting coil 2 was started.
The comparator 34 is turned on and an exciting coil cutoff signal is generated.

As shown in the present embodiment, the energization time of the exciting coil 2 becomes constant by generating the exciting coil cutoff signal after a predetermined time has passed since the energization of the exciting coil 2 was started. As a result, the value of the energizing current of the exciting coil 2 is stabilized, and the output fluctuation of the generator 1 (see the first embodiment) and the flicker of the lamp and the like can be suppressed as compared with the first embodiment.

In this embodiment, the signal stopping means 37 shown in the first embodiment is mounted, and when the temperature of the exciting coil 2 rises, the generator by the power generation requesting means 13 (see the first embodiment). The excitation coil 2 may be energized only for the first power generation request.

[Modification] In the above embodiment, an example in which the generation of the exciting coil cutoff signal is stopped when the internal temperature of the exciting current control circuit rises above a predetermined temperature has been described. It is also possible to detect the surface temperature or the internal temperature of the generator related to the above, and stop the generation of the exciting coil cutoff signal when the detected temperature of the generator rises above a predetermined temperature. In addition, an example was shown in which the excitation current control circuit was equipped with signal stopping means that stops the generation of the excitation coil cutoff signal when the temperature reaches or exceeds a predetermined temperature. It may be provided so as to generate a coil cutoff signal. An example in which the present invention is applied to the exciting current control circuit of the high side power save circuit in which the switching means is connected to the positive potential side of the exciting coil has been shown.
The present invention may be applied to the exciting current control circuit of the low side power save circuit in which the switching means is connected to the negative potential side of the exciting coil.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram showing a configuration of a power generation device (first
Example).

FIG. 2 is an electric circuit diagram of a signal generating means (first embodiment).

FIG. 3 is a time chart for explaining the operation (first
Example).

FIG. 4 is an electric circuit diagram of a signal generating means (second embodiment).

FIG. 5 is a time chart for explaining the operation (second)
Example).

FIG. 6 is an electric circuit for adjusting the exciting current (prior art).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 generator 2 exciting coil 3 armature coil 7 exciting current control circuit 9 return circuit 12 switching means 13 power generation requesting means 14 power generation suppressing means 23 return current detecting element 29 signal generating means 37 signal stopping means

Claims (5)

[Claims] 1. A generator including an exciting coil for generating a magnetic field and an armature coil for rotating relative to the exciting coil to generate electric power, and switching for energizing and interrupting the exciting coil. An exciting current control circuit for controlling the exciting current by controlling the switching means, and a return circuit for supplying a return current to the exciting coil when the energization of the exciting coil is cut off by the switching means. In the power generator, the excitation current control circuit includes a return current detection element that detects a return current value in the return circuit, and the return current detection unit detects the return current when the switching unit cuts off energization of the excitation coil. While the return current value detected by the element exceeds a predetermined value, the switching means shuts off the energization of the exciting coil. Power generation apparatus comprising: a power generation suppression means. 2. The power generator according to claim 1, wherein the power generation suppressing unit has a signal generating unit that oscillates at a predetermined cycle to generate an exciting coil cutoff signal, and the exciting coil cutoff generated by the signal generating unit. A power generator, wherein the energization of the exciting coil is cut off based on a signal. 3. The power generation device according to claim 1, wherein the power generation suppressing means has a signal generating means for generating an exciting coil cutoff signal after a predetermined time has passed since the energization of the exciting coil was started. A power generator which cuts off energization of the exciting coil based on the exciting coil cutoff signal generated by the means. 4. The power generator according to claim 2 or 3, wherein the signal generating means includes signal stopping means for stopping the generation of the exciting coil cutoff signal at a predetermined temperature or higher. 5. The high-side power save circuit according to any one of claims 1 to 4, wherein the exciting current control circuit has the switching means provided on a positive potential side with respect to the exciting coil. In the power generator, the return circuit including the return current detection element is provided on the negative potential side of the switching means.