JPH0232857B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a load drive device for a vehicle.
In particular, the present invention provides a device for detecting whether or not an alternating current generator is generating power, and driving a load depending on whether or not an alternating current generator is generating power.

[Conventional technology]

Conventionally, as shown in Japanese Unexamined Patent Publication No. 55-23747, when the generated voltage of an alternator rises and the generated voltage is below a predetermined value, a first transistor is made conductive to drive a lamp. When the value exceeds the value, the second transistor is made conductive to drive the electric load.

[Problem that the invention seeks to solve]

However, in the conventional system described above, the first and second transistors are made conductive depending on whether the generated voltage is higher than a predetermined value, but the generated voltage of the generator rises steeply and includes many ripples. Therefore, there is a problem that the first and second transistors may become conductive at the same time, resulting in damage to these transistors.

[Means to solve the problem]

Therefore, in order to solve the above-mentioned problems, the present invention provides a generator for charging a battery, and adjusts the generated voltage of the generator to maintain the battery at a predetermined voltage by turning on a key switch. a voltage regulator; a first electrical load and a second electrical load connected in series to both ends of the battery via a key switch; and a first electrical load connected to both ends of the second electrical load. a second transistor connected to both ends of the first electrical load; first and second comparing means for respectively driving the first and second transistors; and power generation of the alternating current generator. Along with smoothing the voltage,
a smoothing circuit connected to the first and second comparing means, and the first comparing means detects when the generated voltage smoothed by the smoothing circuit is equal to or less than a first set value.
The first transistor is driven to supply current to the first electric load, and the second comparison means is configured to drive the first transistor to supply a current to the first electric load, while the second comparison means is configured to drive the first transistor to supply a current to the first electric load, The present invention provides a load driving device for a vehicle, characterized in that when the current is equal to or higher than a set value of 2, the second transistor is driven to supply current to the second electric load.

[Effect]

In order to reduce the steep rise and ripple of the generated voltage of the generator, the first and second comparison means have a smoothing circuit and input the output of this smoothing circuit. transistors, respectively, and can drive two electrical loads, respectively.

〔Effect of the invention〕

As described above, in the present invention, even when the generated voltage rises sharply and includes ripples, simultaneous conduction of the first and second transistors is reliably prevented, and each electrical load is reliably controlled. It has the excellent effect of being able to be driven.

〔Example〕

The present invention will be explained below with reference to embodiments shown in the drawings. FIG. 1 shows a first embodiment, in which 1 is an alternator equipped with a rectifier, 3 is a battery that is charged by the generated voltage of the alternator 1, and 4 is a key switch connected to the battery 3. The key switch 4 is connected to first and second electric loads 5 and 6 connected in series.

Furthermore, a transistor 21 that controls the excitation current of the alternator 1, a voltage regulator 22 that detects the charging voltage to the battery 3 of the alternator 1 at a terminal 201, and thereby controls the transistor 21;
A load drive circuit 23 that drives the first and second loads 5 and 6 is provided.

Next, the load drive circuit 23 will be explained.

The Zener diode 231 is for forming a constant voltage, and this constant voltage is connected to the resistors 234 and 23.
5,236 to produce two different values of divided voltage. These become reference voltages applied to the (-) side input terminals of the first and second voltage comparators 251 and 252, respectively.

The smoothing circuit 24 is for rectifying and smoothing the generated output voltage of the alternator 1 (-phase voltage of the armature coil) inputted to the terminal 203, and this smoothed generated output voltage is applied to the voltage comparator. 251 and 2
52 (+) side input terminal.

Transistor 261 is controlled by the output of voltage comparator 251, and this transistor 261 controls first transistor 262. Further, transistor 271 is controlled by the output of voltage comparator 252, and this transistor 271 controls second transistor 272.

The first electric load 5 such as a charging indicator light has the transistor 272 non-conducting and the transistor 262
The second electric load 6, such as a chiyoke coil, is driven by the transistor 262 being conductive.
is non-conductive and transistor 272 is conductive. Here, the chiyoke coil is used for the automatic chiyoke that warms up the engine, and by supplying current to the chiyoke coil after the generator starts generating electricity, this chiyoke coil generates heat, warms the bimetal, and activates the chiyoke valve. Used for things that open automatically.

The operation will be described below. First, a case will be described in which the AC generator 1 starts generating power and the generated voltage generated at the terminal 203 increases. Rectified and smoothed power generation output voltage Vp applied to the (+) side input terminals of voltage comparators 251 and 252,
The first reference voltage applied to the (-) side input terminal of the voltage comparator 251 is Vref1, and the second reference voltage applied to the (-) side input terminal of the voltage comparator 252 is Vref1.
Set it to Vref2. Here, Vref1<Vref2. Since the AC generator 1 is Vp0 when not generating electricity,
The outputs of voltage comparators 251 and 252 turn off transistors 261 and 271, respectively. Therefore, the second transistor 272 becomes non-conductive, and the first transistor 262 becomes conductive, so that the first load 5 is driven.

When AC generator 1 starts generating electricity, Vp increases. In the region where the power generation output voltage Vp is still Vp<Vref1, the state is the same as in the case of no power generation, but when Vref1<Vref1
When Vp<Vref2, the output of the voltage comparator 251 is inverted, and the transistor 261 changes from non-conductive to conductive. For this reason, the first transistor 262
becomes non-conducting. Second transistor 272 also remains non-conducting. Then, when Vp further increases and becomes Vref2<Vp, the output of the voltage comparator 252 is inverted, and the transistor 271 changes from non-conductive to conductive. Therefore, the second transistor 272 changes from non-conductive to conductive, and since the first transistor 262 is already in the non-conductive state as described above, the second load 6 is driven.

Conversely, when the AC generator 1 stops generating electricity and Vp decreases, the process is reverse to the above-described case where Vp increases. In other words, when Vref2<Vp, the transistor 272 was conductive and the transistor 262 was non-conductive, but when Vref1<Vp<
At Vref2, transistors 262 and 272
Both become non-conductive, and when Vp<Vref1, the transistor 262 becomes conductive and the transistor 272 becomes non-conductive. In this way, both the first and second transistors 262 and 272 do not become conductive at the same time even in the transition region where the value of Vp increases or decreases.

In other words, even if the generated voltage Vp of the generator 1 rises steeply or includes ripples, the first,
Simultaneous conduction of the second transistors 262 and 272 can be reliably prevented, and the first and second electric loads 5 and 6 can be reliably driven, respectively.

Next, a second embodiment will be explained with reference to FIG. As shown in FIG. 2, the same reference voltage is applied to the (-) side input terminals of the first and second voltage comparators 251 and 252, and the (+) side input terminal of the first voltage comparator 251 Even if the generated output voltage Vp is applied to the input terminal of the second voltage comparator 252, and aVp (a<1) obtained by dividing the generated output voltage by a resistor is applied to the (+) side input terminal of the second voltage comparator 252, the embodiment shown in FIG. The same effect as described in can be achieved.

In each of the above embodiments, one phase of the three-phase output is taken out as the power generation output of the alternator 1, but this may be a signal whose output changes depending on whether the alternator is generating or not generating power. It may be realized by any means. For example, it may be a three-phase neutral point output or an output terminal obtained by full-wave rectification of the three-phase output using an auxiliary rectifier.

Further, in each of the above embodiments, the transistor 26
Although an NPN type is used for the transistor 2 and a PNP type is used for the transistor 272, each may be changed to a type of opposite conduction type, and there is no particular restriction on the conductivity type of these transistors.

[Brief explanation of drawings]

FIG. 1 is an electrical wiring diagram showing a first embodiment of the invention, and FIG. 2 is an electrical wiring diagram showing a second embodiment of the invention. 1... AC generator, 3... Battery, 4... Key switch, 5, 6... First and second electric loads,
22... Voltage adjustment circuit, 23... Load drive circuit,
24... Smoothing circuit, 251, 252... Voltage comparator, 262, 272... Transistor.

Claims (1)

[Scope of Claims] 1. A generator 1 for charging a battery 3; A voltage regulator 22 that adjusts the generated voltage of the generator to maintain the battery at a predetermined voltage by turning on the key switch 4; A first electric load 5 connected to both ends of the battery through a key switch and connected in series.
and a second electric load 6; a first transistor 262 connected to both ends of the second electric load; a second transistor 272 connected to both ends of the first electric load; and the first transistor 272 connected to both ends of the first electric load. , first and second comparison means 251 and 252 that drive the second transistors, respectively; and smoothing the generated voltage of the alternator,
and a smoothing circuit 24 connected to the first and second comparing means, and the first comparing means is configured to perform a smoothing operation when the generated voltage smoothed by the smoothing circuit is equal to or lower than a first set value.
the first transistor is driven to supply a current to the first electric load; 2. A load driving device for a vehicle, wherein the second transistor is driven to supply current to the second electric load when the current is equal to or higher than a set value of 2.