JPS5821318Y2 - charging display device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a charge display device for a storage battery that is charged by the rectified output of an alternating current generator.

First, a conventional device of this type is shown in FIG. 1 and will be explained.

In FIG. 1, reference numeral 1 denotes an alternating current generator installed in a vehicle (not shown) and driven by an internal combustion engine (not shown), with an armature coil 101 and a field coil 10 connected in a three-phase star shape.
It has 2.

103 is a neutral point of the armature coil 101; 2 is a full-wave rectifier that rectifies the AC output of the generator 1; 3 is a device that controls the field current flowing through the field coil 102 of the AC generator 1; This is a voltage regulator that controls the output voltage of the alternating current generator 1 to a predetermined value, and is composed of the following parts.

That is, 301 is a surge absorbing diode connected to both ends of the field coil 1020, and 302 is a PN which is a first switching element that cuts off the field current of the field coil 102.
P-type power transistor, 303 is said transistor 3
020 a resistor constituting the base circuit; 304 an NPN transistor that connects and connects the transistor 302; 305
is a resistor forming the base circuit of the transistor 3040,
306 is an NPN type ff11 transistor which is a second switching element that switches on and off the transistor 304, and 307 is a zener transistor that detects the output voltage of the generator 1 and becomes conductive when the output voltage reaches a predetermined value. Diode, 308
．． 309 are resistors connected in series between the output terminals of the full-wave rectifier 2 of the generator 1 and forming a voltage dividing circuit;
310 is a surge absorbing avalanche diode connected between the key switch 6 and ground.

Reference numeral 4 denotes a charging display device that displays the charging state of the storage battery 5, and is composed of the following parts.

That is, 401 is an NPN type power transistor which is the third switching element that connects the charging indicator light 7 connected from the storage battery 5 via the key switch 6, 402 is the transistor, and a resistor forming the base circuit of 401. 403 is an NPN type control transistor which is a fourth switching element that switches on and off the transistor 401; 404 is the transistor 4;
03 is a capacitor inserted in series between the collector and base, 405 is a current limiting resistor inserted in series with the base of the transistor 4030, and 406 is a cathode connected to the resistor 4.
05 is a backflow blocking diode whose anode is connected to the neutral point 103, and 407 is connected to the neutral point 103.
408 is a gauge absorption capacitor of the power transistor 401, and 409 and 410 are each inserted in series between the key switch 6 and the neutral point 103. The resistor 411 is a diode whose anode is connected to the connection point of the resistors 409 and 411, and whose cathode is connected to the collector of the transistor 304 of the voltage regulator 3.

The operation of the conventional device configured as above will be explained.

First, when the key switch 6 is closed when starting the engine, base current flows from the storage battery 5 to the transistor 304 via the key switch 6 and the resistor 305.
4 is conductive.

When the transistor 304 becomes conductive, a base current flows from the storage battery 5 to the transistor 302 via the key switch 6, the emitter-base resistor 303 of the transistor 302, and the collector-emitter of the transistor 304, causing the transistor 302 to become conductive.

When the transistor 302 becomes conductive, a field current flows from the storage battery 5 to the field coil 102 via the key switch 6 and the emitter/collector of the transistor 302, and a field magnetomotive force is generated in the field coil 102.

On the other hand, at this time, from the storage battery 5 to the key switch 6 and the resistor 402
A base current flows to the transistor 401 through the transistor 401, and the transistor 401 becomes conductive.

When the transistor 401 becomes conductive, current flows from the storage battery 5 to the charge indicator 7 through the key 4, switch 6, charge indicator 7, and collector of the transistor 401, and the charge indicator 7 lights up. Displays the non-charging state of the storage battery 5.

At this time, the transistor 304 is conductive, so the storage battery 5
The potential generated in the resistor 409 flows through the key switch 6 between the collector and emitter of the transistor 304 through the diode 411, and the potential at the connection point between the resistors 409 and 410 becomes a low value.

Also, at this time, alternator 1 is not generating voltage, so
No voltage is generated at the neutral point 103, and the transistor 403
remains blocked.

Next, when the engine is started in this state, the generator 1 is driven and rotates.

Then, an AC output corresponding to the rotation speed is induced in the armature coil 101.

The AC output is full-wave rectified by the full-wave rectifier 2, but if this rectified output is below a predetermined value, the voltage dividing point potential of the voltage dividing circuit composed of resistors 308 and 309 is extremely low. Zener diode 307 maintains a non-conducting state,
As a result, the output voltage of the generator 1 increases as the rotational speed increases.

Thereafter, the number of revolutions of the generator 10 further increases, and the output voltage further increases accordingly, and if it exceeds a predetermined value, the voltage dividing point potential of the voltage dividing circuits 308 and 309 also increases, thereby causing the zener diode 307 is conductive, and the base current flows to the transistor 306 through the Zener diode 307, and the transistor 306 is conductive.

When the transistor 306 conducts, the transistor 304
The 0 base current is cut off and transistor 304 is cut off.

When the transistor 304 is cut off, the transistor 304
The collector current, that is, the base current of the transistor 3020 is cut off, the transistor 302 is cut off, the field current flowing through the field a coil 102 decreases, and the output voltage of the generator 1 also decreases.

When this output voltage falls below a predetermined value, the Zener diode 307 and the transistor 306 become non-conductive, the transistors 304 and 302 become conductive, the field current increases again, and the output voltage of the generator 1 increases again.

The output voltage of the generator 1 is controlled to a predetermined value by repeating the above-described operation, and the storage battery 5 is charged to the predetermined voltage using this controlled voltage.

On the other hand, when the generator 1 generates an AC output, a voltage of about 0 of the system voltage is generated at the neutral point 103 of the armature coil 101.

This voltage is the sum of the base-emitter voltage of the transistor 4030 and the forward voltage drop of the diode 406 (approximately 1.5
V), a base current flows through the transistor 403 and it becomes conductive.

When the transistor 403 becomes conductive, the transistor 40
1 becomes non-conductive and the charging indicator lamp 1 goes out to display the charging state of the storage battery 5.

The above is a case where the wiring etc. are appropriately designed, but if the voltage regulator 3 If the intermittent period of
Even if the output voltage of the generator 1 and the voltage at the neutral point 103 decrease, the collector potential of the transistor 304 is high, so the base current flows to the transistor 403 via the storage battery 5, the key switch 6, the resistor 409, the 410 diode 406, and the resistor 405. Since this continues to be supplied, the transistor 401 maintains a cut-off state, and the charging indicator light 7 continues to turn off, so that malfunctions such as blinking and flickering do not occur.

However, in the conventional device described above, when a failure occurs in which the transistor 304 becomes open, the transistor 302 also becomes non-conductive and no field current flows through the field coil 102, so that the generator 1 is turned off by the engine. Even if it is driven, it will not generate electricity.

However, in the charge display device 4, the cathode terminal of the diode 4110 has a high potential, so a base current flows from the storage battery 5 through the key switch 6 resistor 409, 410, diode 406, and resistor 405, and the transistor 403 becomes conductive.

Therefore, the transistor 401 is cut off, and the charging indicator light 7 incorrectly displays the charging state even though the storage battery 5 is in a non-charging state.If the driver does not notice, the storage battery 5 is discharged.
It had a defect that made it impossible to drive.

This invention provides an excellent charging display device that eliminates the above-mentioned drawbacks.

An embodiment of this invention shown in FIG. 2 will be described below.

In FIG. 2, 412 is a diode whose cathode is connected to the base of the transistor 4010 and its anode is connected to the collector of the transistor 403. 413 is a diode whose cathode is connected to the collector of the transistor 306 of the voltage regulator 3, and the collector of the transistor 403 of the charging display device 4. It is a diode with an anode connected to.

The operation of the embodiment device configured as above will be explained.

First, when the key switch 5 is closed when starting the engine, a base current flows from the storage battery 5 to the transistor 401 via the key switch 6, the resistor 402, and the diode 412, making the transistor 401 conductive, and the charging indicator light 7 lights up. Displays the non-charging state of the storage battery 5.

Next, when the engine is started and a voltage is generated in the generator 1, a voltage is also generated at the neutral point 103, and this generated voltage causes the transistor 403 to become conductive and the transistor 401 to become non-conductive, thereby indicating the state of charge of the storage battery 4.

Then, when the output voltage of the generator 1 exceeds a predetermined value of the voltage regulator 3, the transistor 306 starts to turn on and off.

At this time, when the transistor 306 is in a conductive state, it cuts off the base current flowing to the transistor 304 and also cuts off the base current of the transistor 401. Therefore, for some reason, the intermittent cycle of the voltage regulator becomes longer, and the cut-off time is longer. This prevents the charging indicator γ from blinking or flickering due to the voltage drop at the neutral point 103 that occurs.

Furthermore, in the event of an open failure in the transistor 304, which was a problem in the conventional device, the transistor 306 is in a cut-off state and there is no generated voltage at the neutral point 103, so the transistor 401 is conductive and the charging indicator light 7 is lit, indicating that the storage battery 5
Since the non-charging state of the battery 5 is displayed, a warning is issued to the driver, and secondary failures such as inability to drive due to discharge of the storage battery 5 can be prevented.

Similarly, when the generator 1 fails to generate voltage due to an open failure of the transistor 302 and the resistor 303, the charging indicator light 7 lights up to indicate the non-charging state of the storage battery 5.

In the above-mentioned embodiment, the same effect can be obtained even if the field coil 102 is connected to a common type.

As described above, this invention includes a storage battery that is charged by the rectified output of a traffic generator having a field coil, a transistor 117) that intermittents the field current flowing through the field coil, and the first transistor. A collector is connected to the base of the AC generator, and a second transistor is connected to the storage battery, and a second transistor that controls the output voltage of the generator to a predetermined value by intermittent operation of the first transistor according to the rectified output voltage of the AC generator. a charging indicator light capable of displaying the state of charge of the storage battery; a third transistor connected to the lighting circuit of the charging indicator light to control lighting of the charging indicator; and a base connected to the neutral point of the alternator. a fourth transistor whose collector is connected to the base of the third transistor and which controls the third transistor intermittently according to the neutral point output voltage of the alternator; a first diode connected to the base of the third transistor and the collector of the fourth transistor, respectively;
a second diode whose cathode and anode are respectively connected to the collector of the second transistor and the collector of the fourth transistor, and when the second transistor is conductive, the base current of the third transistor is Since the second transistor was bypassed and the third transistor was cut off, for some reason the intermittent cycle of the voltage regulator, that is, the cut-off time became longer, resulting in a voltage drop at the neutral point. Even in cases where the base current of the third transistor is bypassed by the second transistor, the third transistor is cut off, so the charging indicator lamp does not blink or flicker due to the voltage drop at the neutral point. Furthermore, if an accident occurs in which the first transistor becomes open, the fourth transistor is cut off due to the decrease in the neutral point output voltage and the third transistor becomes conductive, so that the charging display is not displayed. The light will turn on, giving a warning to the driver and preventing secondary failures.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram showing a conventional device, and FIG. 2 is an electric circuit diagram showing an embodiment of this invention. In the figure, 1 is an alternating current generator 2 is a full-wave rectifier, 3 is a voltage regulator, 4 is a charging display device, 412 and 413 are diodes,
302 is a first switching element, 306 is a second switching element, 4
01 is a third switching element, 403 is a fourth switching element, 5 is a storage battery, 6 is a key switch, and 7 is a charging indicator light. Note that the same reference numerals in the drawings indicate the same or equivalent parts.

Claims (1)

[Scope of utility model registration request] A storage battery charged by the rectified output of an alternating current generator having a field coil; a first transistor connected to the current-carrying circuit of the field coil to intermittent the field current flowing through the field coil; a second transistor, the collector of which is connected to the base, controls the output voltage of the generator to a predetermined value by intermittent operation of the first transistor according to the rectified output voltage of the alternating current generator; A charging indicator that can display the charging status of the storage battery;
The base of a third transistor connected to the lighting circuit of the charging indicator and controlling the lighting of the charging indicator is connected to the neutral point of the alternator, and the collector is connected to the base of the third transistor. and a fourth transistor for controlling the third transistor intermittently according to the neutral point output voltage of the alternator, the cathode and the anode of which are connected to the base of the third transistor and the collector of the fourth transistor, respectively. a first diode connected to the transistor; and a second diode, the cathode and the anode of which are connected to the collector of the second transistor and the collector of the fourth transistor, respectively.
a diode, and when the second transistor is conductive, the base current of the third transistor is bypassed by the second transistor to cut off the third transistor. Device.