JP3638925B2 - Heater control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle heater control device, and more particularly to a vehicle heater control device when a heater provided in each part of a vehicle is driven by a power supply voltage output from a battery.
[0002]
[Prior art]
Generally, in a vehicle such as a two-wheeled vehicle or an automobile, a heater for keeping each part warm is provided. For example, in motorcycles, etc., a heater is provided in the handle grip, or in automobiles, etc., a heater is provided in the seat seat, and each part is kept warm by controlling the power supplied to these heaters. It is intended to provide.
[0003]
Conventionally, this type of vehicle heater control device has a configuration as shown in FIG. 6, for example. In the figure, HT-L and HT-R are heaters provided on the left and right handle grips of a two-wheeled vehicle or the like, and supply the power supply voltage Vbatt from the battery BATT to the heaters HT-L and HT-R via the switch SW. In addition, a variable resistor RV is provided in series with these heaters HT-L and HT-R, and the electric current consumed by the heater is controlled by changing the current flowing through the heaters HT-L and HT-R. The grip was kept at an appropriate temperature.
[0004]
[Problems to be solved by the invention]
However, in such a conventional heater control apparatus for a vehicle, a variable resistor is provided in series with the heater so as to control the power consumed by the heater. However, there is a problem that the battery cannot be used efficiently. In particular, in the case of a grip heater provided on a handle such as a two-wheeled vehicle, the power consumption is large because it directly touches the outside air, and the variation range of the outside air temperature is large. There was a problem that it could not be used efficiently.
The present invention is intended to solve such problems, and an object thereof is to provide a vehicle heater control device that can efficiently use a battery.
[0005]
[Means for Solving the Problems]
In order to achieve such an object, a vehicle heater control device according to the present invention includes a periodic voltage generating means for generating a periodic voltage whose voltage value periodically changes, and a predetermined comparison according to a temperature adjustment operation on the heater. A comparison voltage output means for outputting a voltage, a rectangular wave output means for outputting a rectangular wave signal having a duty ratio corresponding to the temperature adjustment operation by comparing the periodic voltage and the comparison voltage, and a response to the rectangular wave signal And switching means for controlling on / off of the electric power supplied from the battery to the heater.
Therefore, a periodic voltage whose voltage value changes periodically is compared with a predetermined comparison voltage according to a temperature adjustment operation for a heater, for example, a grip heater of a handle, and a rectangular wave signal is output. Thus, the power supplied to the heater is turned on / off by the power supply voltage from the battery.
[0006]
Also, the power supply voltage output from the battery is monitored, and when the power supply voltage drops below a predetermined value, a rectangular wave signal that controls the switching means to be turned off is forcibly output by holding the comparison voltage at a predetermined value. Battery voltage monitoring means to be provided. Therefore, the power supply voltage output from the battery is monitored, and when the power supply voltage drops below a predetermined value, the comparison voltage is held at the predetermined value and a rectangular wave signal for controlling the switching means to be turned off is forcibly output. The
In addition, when the comparison voltage from the comparison voltage output means becomes indefinite, a fail safe means for forcibly outputting a rectangular wave signal for controlling the switching means to be turned off by holding the comparison voltage at a predetermined value is provided. Is. Therefore, when the comparison voltage from the comparison voltage output means becomes indefinite, the comparison voltage is held at a predetermined value and a rectangular wave signal for controlling the switching means to be turned off is forcibly output.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be described with reference to the drawings.
FIG. 1 is a circuit diagram of a vehicle heater control apparatus according to an embodiment of the present invention. Here, a case where a grip heater provided on a handle grip of a motorcycle or the like is controlled will be described as an example.
In the figure, 1 is a constant voltage output unit that outputs a predetermined constant voltage Vc based on a power supply voltage Vbatt input from a battery (storage battery) BATT mounted on the vehicle via a switch SW, and 2 is a constant voltage Vc. A triangular wave generator (periodic voltage generating means) that outputs a triangular wave voltage (periodic voltage) Vt that changes at a predetermined cycle based on the reference voltage 3, and a comparison voltage output unit that outputs a comparative voltage Vp for temperature adjustment based on the constant voltage Vc It is.
[0008]
4 is a fail-safe unit for setting the comparison voltage Vp to a predetermined voltage value when the comparison voltage Vp becomes indefinite, and 5 is for outputting a predetermined rectangular wave signal Vout by comparing the triangular wave voltage Vt with the comparison voltage Vp. The rectangular wave output unit 6 monitors the power supply voltage Vbatt from the battery BATT based on the reference voltage Vs generated from the constant voltage Vc. When the power supply voltage Vbatt falls below a predetermined value, the comparison voltage Vp is set to a predetermined voltage value. The battery voltage monitoring unit to be set, TR is a transistor for controlling on / off of the current supplied to the heaters HT-L and HT-R based on the rectangular wave signal Vout supplied from the rectangular wave output unit 5 through the resistor R (Switching means).
[0009]
4A and 4B are explanatory views showing a grip heater, in which FIG. 4A shows a handle grip portion such as a two-wheeled vehicle, and FIG. 4B shows an entire handle portion such as a two-wheeled vehicle.
In FIG. 4A, 41 is a handle, 42 is a brake lever, 43 is a handle grip formed in a cylindrical shape from an insulator such as synthetic resin or rubber, and 44 is a grip heater. In this case, the grip heater 44 is composed of a flexible printed wiring board (FPC) having a predetermined pattern circuit, and is embedded in the handle grip 43.
[0010]
In FIG. 4B, 45 is a panel portion provided with a speedometer, 46 is a body portion below the panel portion 45, and 47 is a vehicle heater control device disposed in the body portion 46.
The vehicle heater control device 47 is provided with a knob 48 of the variable resistor RV3 in which the above-described switch SW (see FIG. 1) is integrated. By operating this knob 48, the switch SW is turned on / off. Off control and temperature adjustment of the heater 44 connected via wiring (not shown) are performed.
[0011]
5A and 5B are explanatory views showing a heater control device for a vehicle, in which FIG. 5A is a front view, FIG. 5B is a side view, and FIG. 5C is a cross-sectional view.
In FIG. 5 (c), 51 is a board unit in which each of the circuit sections described above (see FIG. 1) is configured, 52 is a vent hole for venting the inside of the apparatus, and the end of the vent hole 52 on the inside of the apparatus Is covered with a water-permeable air-permeable sheet 53 for preventing water from entering from the outside.
As shown in FIG. 5A, the switch SW is turned off by operating the knob 48 to the OFF position, and the temperature of the heater is adjusted by operating between the LO position and the HI position.
[0012]
Next, the operation of the present invention will be described with reference to FIG.
The power supply voltage Vbatt of the battery BATT is supplied to the constant voltage output unit 1 through the switch SW. In the constant voltage output unit 1, a resistor R1 and a Zener diode ZD1 are connected in series between the power supply voltage Vbatt and the ground potential, and a constant voltage Vc is output from the middle point. C11 and C12 are smoothing capacitors.
In the triangular wave generator 2, the operational amplifier IC2 compares the reference voltage Vd obtained by dividing the constant voltage Vc with the resistors R21 and R22 with the charging voltage (= triangular wave voltage Vt) of the capacitor C2, and the output of the resistor R23 The triangular wave voltage Vt is generated by charging / discharging the capacitor C2 via. A chattering prevention resistor R24 is provided between the output terminal and the + input terminal of the operational amplifier IC2.
[0013]
FIG. 2 is a timing chart showing the voltage of each part when the heater is driven. In the triangular wave generator 2, a predetermined value as shown in FIG. 2 is obtained based on the time constant between the capacitor C2 and the resistor R23 and the reference voltage Vd. A triangular wave voltage Vt having a period and an amplitude is generated and output to the rectangular wave output unit 5.
On the other hand, in the comparison voltage output unit 3, the comparison voltage Vp corresponding to the temperature adjustment operation is output to the rectangular wave output unit 5 from the middle point of the variable resistor RV3 connected in series between the constant voltage Vc and the ground potential. The
[0014]
In the rectangular wave output unit 5, the triangular wave voltage Vt and the comparison voltage Vp are compared by the operational amplifier IC5, and when the triangular wave voltage Vt is lower than the comparison voltage Vp, the rectangular wave signal Vout is set to “H level” (constant voltage Vc level). When the triangular wave voltage Vt is higher than the comparison voltage Vp, the rectangular wave signal Vout is set to “L level” (ground potential). A resistor R5 for preventing chattering is provided between the output terminal and the + input terminal of the operational amplifier IC5.
[0015]
The rectangular wave signal Vout is supplied to the gate terminal of the transistor TR (FET) via the resistor R, and the transistor TR is turned on / off according to the level of the rectangular wave signal Vout.
As a result, as shown in FIG. 2, the heaters HT-L and HT-R are turned on / off at a predetermined duty ratio, that is, at a ratio of a predetermined on-time (energization time) Ton and off-time (non-energization time) Toff. The duty ratio is adjusted by the comparison voltage Vp from the variable resistor RV3. C is a capacitor for removing electrostatic noise from the transistor TR.
[0016]
In this way, the triangular wave generator 2 that outputs a predetermined triangular wave voltage Vt and the comparative voltage output unit 3 that outputs a comparative voltage Vp corresponding to the temperature adjustment operation are provided, and the triangular wave voltage Vt and the comparative voltage Vp are obtained. Since the transistor TR is controlled by the rectangular wave signal Vout output as a comparison result, the duty ratio of the current supplied from the battery BATT to the heaters HT-L and HT-R is changed. Compared to the conventional case where a variable resistor is provided in series with the heater to control the power consumed by the heater, there is no wasteful power consumption in the variable resistor, and the battery can be used efficiently. it can.
[0017]
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a timing chart showing voltages at various parts when the power supply output voltage Vbatt of the battery is lowered.
The battery voltage monitoring unit 6 divides the power supply voltage Vbatt obtained from the input stage of the constant voltage output unit 1 by resistors R61 and R62, thereby generating a proportional voltage Vb that changes in proportion to the power supply voltage Vbatt. C6 is a capacitor for noise removal.
[0018]
The constant voltage Vc from the constant voltage output unit 1 is divided by resistors R63 and R64 to obtain a reference voltage Vs, and the reference voltage Vs and the proportional voltage Vb are compared by the operational amplifier IC61, so that the power supply is always supplied. The voltage Vbatt is monitored. A resistor R65 for preventing chattering is provided between the output terminal and the + input terminal of the operational amplifier IC61.
When the battery BATT is sufficiently charged and the power supply voltage Vbatt is high to some extent, the proportional voltage Vb becomes a value higher than the reference voltage Vs, and the output of the operational amplifier IC61 becomes “L level” (ground potential).
[0019]
The output of the operational amplifier IC61 is compared with the reference voltage Vs in the operational amplifier IC62 having an open collector (open drain) output. In this case, the operational amplifier IC61 outputs "L level" lower than the reference voltage Vs. “H level” is output.
The output of the operational amplifier IC62 is connected to the + input terminal of the operational amplifier IC5 of the rectangular wave output unit 5, that is, the comparison voltage Vp. Since “H level” is output and disconnected (open) here, the comparison voltage Vp is output. Is not changed, and the rectangular wave signal Vout as described above (see FIG. 2) is output to the transistor TR.
[0020]
On the other hand, when the battery BATT is insufficiently charged and the power supply voltage Vbatt decreases and the proportional voltage Vb falls below the reference voltage Vs, the output of the operational amplifier IC61 becomes “H level” (constant voltage Vc). Therefore, since “H level” higher than the reference voltage Vs is output from the operational amplifier IC61, “L level” is output from the operational amplifier IC62.
As a result, the comparison voltage Vp is drawn into the operational amplifier IC62, drops to almost the ground potential, and is held at a value lower than the lowest voltage Vmin of the triangular wave voltage Vt as shown in FIG.
[0021]
Accordingly, the “L level” rectangular wave signal Vout is output from the IC 5 of the rectangular wave output unit 5, the transistor TR is held in the OFF state, and the driving of the heaters HT-L and HT-R is stopped.
As described above, the power supply voltage Vbatt output from the battery BATT is monitored, and when the voltage falls below a predetermined voltage value, the rectangular wave output unit 5 outputs the rectangular wave signal Vout indicating the heater driving stop. Even when the switch SW is left on, overdischarge of the battery mounted on the vehicle can be avoided.
[0022]
Next, a third embodiment of the present invention will be described with reference to FIG. Here, a fail safe unit 4 is provided between the comparison voltage output unit 3 and the rectangular wave output unit 5 to stabilize the comparison voltage Vp.
In the comparison voltage output unit 3, a variable resistor RV3 is used to output a predetermined comparison voltage Vp corresponding to the heater temperature in accordance with the operation.
In general, a variable resistor has a contact that slides on a resistor in response to an operation, and there is a possibility that contact failure may occur due to aging or dust.
[0023]
In the fail safe unit 4, the + input terminal of the operational amplifier IC5 to which the comparison voltage Vp is input and the ground voltage are connected by a resistor R4 having a sufficiently large value compared to the variable resistor RV3, for example, and the variable resistor RV3 Since the rectangular wave signal Vout indicating the heater drive stop is output from the rectangular wave output unit 5 by setting the comparative voltage Vp to the ground potential when the comparative voltage Vp from the reference voltage Vp becomes indefinite. When the comparison voltage Vp output from the output unit 3 becomes indefinite, excessive heat generation by the heater can be suppressed and consumption of the battery mounted on the vehicle can be reduced.
[0024]
In the above description, when the battery voltage monitoring unit 6 and the fail safe unit 4 stop driving the heater, the rectangular voltage signal Vout indicating the heater driving stop is output by reducing the comparison voltage Vp to the ground potential. Although the case where it did was demonstrated, it is not limited to this.
In the operational amplifier IC5, when the comparison voltage Vp is lower than the lowest voltage Vmin (see FIG. 3) of the triangular wave voltage Vt, the rectangular wave signal Vout (“L level”) indicating the heater drive stop is always output. The comparison voltage Vp may be lowered to a value lower than the lowest voltage of the triangular wave voltage Vt. The minimum voltage Vmin of the triangular wave voltage Vt is determined by the constant voltage Vc, the resistors R21, R22, R24, the “L level” output voltage value of the operational amplifier IC2, and the like.
[0025]
In the above description, the triangular wave Vt is used as a periodic voltage whose voltage value periodically changes, and the triangular wave having a duty ratio corresponding to the temperature adjustment operation is compared by comparing the triangular wave voltage Vt with the comparison voltage Vp. Although the case where the signal Vout is generated has been described, the periodic voltage is not limited to the triangular wave voltage.
As the periodic voltage, any signal can be used as long as it can obtain a rectangular wave signal whose duty ratio changes as a comparison result by changing the voltage value of the comparison voltage Vp, that is, by changing the voltage value of the comparison voltage Vp. For example, a sine wave or the like may be used as the periodic voltage.
[0026]
【The invention's effect】
As described above, the present invention includes the periodic voltage generating means for generating a periodic voltage whose voltage value periodically changes, and the comparison voltage output means for outputting a predetermined comparison voltage corresponding to the temperature adjustment operation on the heater. A rectangular wave signal having a duty ratio corresponding to the temperature adjustment operation is generated by comparing the periodic voltage with the comparison voltage, and the power supplied from the battery to the heater is turned on in accordance with the rectangular wave signal. As compared with the conventional case where a variable resistor is provided in series with the heater to control the power consumed by the heater, there is no wasteful power consumption in the variable resistor. The battery can be used efficiently. In particular, in the case of a grip heater provided on a handle such as a two-wheeled vehicle, the power consumption is large because it directly touches the outside air, and the variation range of the outside air temperature is large. Is possible.
[0027]
In addition, the battery voltage monitoring means is provided to monitor the power supply voltage output from the battery. When the power supply voltage drops below a predetermined value, the switching means is turned off by holding the comparison voltage at the predetermined value. Since the rectangular wave signal to be controlled is forcibly output, overdischarge of the battery mounted on the vehicle can be avoided even when the switch SW is left on.
In addition, when the comparison voltage from the comparison voltage output means becomes indefinite by providing fail-safe means, a rectangular wave signal for controlling the switching means to be turned off is forced by holding the comparison voltage at a predetermined value. Since the output is performed, even when the comparison voltage from the comparison voltage output means becomes indefinite, excessive heat generation can be suppressed by the heater, and consumption of the battery mounted on the vehicle can be reduced.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of a vehicle heater control apparatus according to an embodiment of the present invention.
FIG. 2 is a timing chart showing voltages at various parts when a heater is driven.
FIG. 3 is a timing chart showing voltages at various parts when the power supply output voltage Vbatt of the battery decreases.
FIG. 4 is an explanatory view showing a grip heater.
FIG. 5 is an explanatory diagram showing a vehicle heater control device.
FIG. 6 is a circuit diagram of a conventional vehicle heater control device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Constant voltage output part, 2 ... Triangular wave generation part (periodic voltage generation means), 3 ... Comparison voltage output part, 4 ... Fail safe part, 5 ... Rectangular wave output part, 6 ... Battery voltage monitoring part, TR ... Transistor ( Switching means), HT-L, HT-R ... heater, BATT ... battery (storage battery), Vc ... constant voltage, Vd ... reference voltage, Vt ... triangular wave voltage, Vp ... comparison voltage, Vb ... proportional voltage, Vs ... reference voltage. , Vout ... rectangular wave signal.

Claims (3)

In a heater control device for controlling a heater provided on a vehicle and driven by electric power supplied from a battery,
Constant voltage output means for outputting a predetermined constant voltage based on a power supply voltage from the battery;
A proportional voltage is generated from the voltage at the input stage of the constant voltage output means, a reference voltage is obtained from the constant voltage from the constant voltage output means, and the power supply voltage is calculated by comparing the reference voltage with the proportional voltage. Battery voltage monitoring means for monitoring and outputting a signal indicating a drop in the power supply voltage when the power supply voltage falls below a predetermined value;
A heater control device comprising: means for cutting off electric power supplied from the battery to the heater according to an output signal of the battery voltage monitoring means. In a heater control device for controlling a heater provided on a vehicle and driven by electric power supplied from a battery,
Comparison voltage output means for outputting a predetermined comparison voltage according to a temperature adjustment operation on the heater;
A comparison circuit having a periodically changing voltage as an input voltage of the first input terminal and the comparison voltage as an input voltage of the second input terminal; and an input voltage of the first input terminal and the second input terminal Output means for outputting a signal corresponding to the temperature adjustment operation by comparing the input voltage of the input terminal with the comparison circuit;
Means for controlling the power supplied from the battery to the heater according to the output signal of the output means;
When the power supply voltage output from the battery drops below a predetermined value, a signal indicating the drop in the power supply voltage is supplied to the second input terminal of the comparison circuit, and the power supplied from the battery to the heater is cut off. And a battery voltage monitoring means. In the heater control device according to claim 1 or 2,
The heater control device, wherein the heater is a grip heater provided on a grip of a vehicle.

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