JPH075741Y2 - Remote control transmitter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field> The present invention relates to a remote control transmitter (hereinafter, referred to as “remote control transmitter”) that uses a battery as a power source and includes a microcomputer.

<Prior Art> As a remote control transmitter of this type, for example, there is a so-called memory remote control capable of learning and storing a remote control signal of another remote control transmitter for reproduction.

FIG. 4 is a block diagram of a conventional memory remote controller. In the figure, reference numeral 1 denotes an operation unit having a plurality of keys, 2
Is an encoder unit including a microcomputer, 3 is a transmitting unit that transmits a remote control signal to a controlled device, 4 is a power supply unit that supplies power to each unit, ₅₀ is a power supply voltage from the power supply unit 4 to the encoder unit 2. power switch unit, the shut-off switch control, 6 _0, based on the output voltage of the power supply switch unit 5 _0, reset unit for outputting a reset voltage to the encoder unit 2, 7 a remote control signal from another remote control transmitter A receiving unit for receiving, a signal storage unit 8 for storing the received remote control signals from other remote control transmitters, and a display unit 9 for displaying corresponding to the operation.

FIG. 5 shows the power switch section ₅₀ and the reset section of FIG.
6 is a circuit diagram of a _0, 6 is a waveform diagram showing a voltage change of each part of FIG. 5.

Power switch 5 _0, the voltage detection IC 25, and a buffer 27, a Zener diode 26 and a buffer 28, a power supply voltage Va from the power supply unit 4 shown in FIG. 6 (A) is micro-encoder 2 When the specified voltage (for example, 4V) necessary for setting the computer is reached, the power is turned on to supply the power supply voltage to the encoder unit 2 and the battery of the power supply unit 4 is exhausted as shown in FIG. 6 (B). When the power supply voltage Va becomes equal to or lower than the operable voltage of the encoder unit (for example, 3 V), the power is turned off and the supply of the power supply voltage to the encoder unit 2 is stopped. In the power supply switch unit 5 _0, as shown in FIG. 6 (B), the voltage detection IC 25, a buffer 27, a Zener diode
A hysteresis Vh is provided by 26 and resistors 32, 33.

Reset section 6 _0, charging resistor 29, and a capacitor 30 and diode 31, as shown in FIG. 6 (C), at the time of the supply voltage rise of the power supply switch unit 5 _0, the charging resistor 29 and a capacitor At the time constant determined by 30, the reset voltage Vc is raised to set the encoder unit 2 to start the operation. When the power supply voltage Vb falls, the diode 31 discharges the reset voltage Vc to lower the encoder unit. The operation of 2 is stopped.

In the remote control transmitter of the conventional example having the above-mentioned configuration, when the battery of the power supply unit 4 is exhausted, the power supply is changed due to load fluctuations when the remote control signal is transmitted and when the remote control signal is output. The voltage Va is the encoder unit 2
May be reduced below microcomputer operable voltage of, in this case, the supply of power supply voltage vb from the power switch unit 5 ₀ is cut off, the reset voltage Vc from the reset unit 6 _0, Fig. 7 As shown in, diode 31
Since the power supply voltage to the encoder unit 2 falls after being delayed by the forward voltage Vf, the power supply voltage to the encoder unit 2 becomes lower than the operable voltage before the encoder unit 2 stops its operation, that is, before being reset. Therefore, there is a problem that the microcomputer of the encoder unit 2 malfunctions.

<Object of the Invention> The present invention has been made in view of the above points, and an object of the present invention is to prevent the microcomputer constituting the encoder unit from malfunctioning when the power supply voltage drops.

<Structure of Device> In order to achieve the above object, the present invention includes a battery power source, a microcomputer that constitutes an encoder unit, and
A power switch unit for controlling the supply / cutoff of a power supply voltage from the battery power source to the microcomputer; and a reset unit for outputting a reset voltage to the microcomputer based on the output voltage of the power switch unit. In the remote control transmitter provided,
The power supply switch unit is a voltage detection circuit that outputs a detection voltage when the power supply voltage exceeds a predetermined level, and is charged by the detection voltage and discharged at a predetermined time constant in response to a decrease in the detection voltage. The charging / discharging circuit includes a power supply / interruption circuit for supplying / interrupting the power supply voltage to / from the microcomputer based on an output voltage of the charge / discharge circuit, and the reset unit includes the power supply / interruption circuit. The charging / discharging circuit is configured to be charged with a predetermined time constant by the output voltage and to be discharged immediately in response to the decrease in the detection voltage.

According to the above configuration, the reset voltage falls immediately in response to the decrease in the detection voltage, so that the microcomputer is reliably reset before the power supply voltage supplied from the power supply / interruption circuit to the microcomputer falls. Will stop the operation of the microcomputer, which may cause the power supply voltage to drop.
The microcomputer is prevented from malfunctioning.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and the portions corresponding to the conventional example of FIG.

In the figure, 1 is an operation unit having a plurality of keys, 2 is an encoder unit including a microcomputer, 3 is a transmission unit that transmits a remote control signal to a controlled device, 4 is a plurality of batteries, and each unit is provided with a power supply voltage. A power supply unit 5 supplies power, and a power switch unit controls the supply / interruption of the power supply voltage from the power supply unit 4 to the encoder unit 2. 6 a power switch unit 5
A reset unit that supplies a reset voltage to the encoder unit 2 on the basis of the voltage from, a receiving unit 7 that receives a remote control signal from another remote control transmitter (not shown), and a reference numeral 8 that receives the remote control signal from the other remote control transmitter. A signal storage unit for storing remote control signals and the like, and a display unit 9 for displaying a display corresponding to an operation.

FIG. 2 is a circuit diagram of the power switch unit 5 and the reset unit 6 of FIG.

In the remote control transmitter of this embodiment, the power supply voltage Va to be supplied from the power supply unit 4 to the encoder unit 2 is the encoder unit 2
The power switch section 5 and the reset section 6 are configured as follows in order to prevent the microcomputer from malfunctioning when the voltage becomes lower than the operable voltage of the microcomputer constituting the above.

That is, the power switch unit 5 is charged by the voltage detection circuit 10 that outputs the detection voltage Vd when the power supply voltage Va from the power supply unit 4 exceeds a predetermined level, and the detection voltage Vd.
A charge / discharge circuit 11 that discharges at a predetermined time constant, and a power supply / interruption circuit 12 that supplies / interrupts the power supply voltage to / from the microcomputer of the encoder unit 2 based on the output voltage Ve of the charge / discharge circuit 11. The reset unit 6 includes a charging / discharging circuit that is charged by the output voltage of the power supply / interruption circuit 12 with a predetermined time constant and discharges immediately in response to a decrease in the detection voltage. Outputs a reset voltage Vc that rises with a predetermined time constant in response to the rise of the output voltage Vb of the power supply / interruption circuit 12 and falls in response to the fall of the detection voltage Vb.

The voltage detection circuit 10 of the power switch unit 5 is the voltage detection IC 13
(For example, S-805 series manufactured by Seiko Instruments Inc.) and buffer circuit 14 (for example, high-speed CMOS74
1/6 circuit of the HC4050 type buffer IC), and the buffer circuit 14 functions as a drive for the next stage. Charge / discharge circuit 11 of power switch unit
Is composed of a diode 15, a discharge resistor 16 and a capacitor 17. The power supply / interruption circuit 12 includes a buffer circuit 18 (6 of the high speed CMOS 74HC4050 type buffer IC described above).
1/5 parallel circuit) and turns on when the input voltage exceeds the threshold level to supply the power supply voltage to the encoder unit 2.

The reset unit 5 includes a charging resistor 19, a capacitor 20 and a diode 21.

FIG. 3 is a waveform diagram showing a voltage change in each part of FIG. 2, and the operation will be described based on FIG.

First, when a battery is put in the power supply unit 4, the power supply voltage Va becomes
As shown in FIG. 3 (A), the voltage rises, and the voltage detection circuit 10 of the power switch unit 5 causes the power supply voltage Va to rise.
Is a predetermined level (voltage for setting a microcomputer)
When the voltage exceeds V, the high level detection voltage Vd shown in FIG. 3B is output. This detection voltage Vd is given to the charge / discharge circuit 11, charges the capacitor 17 through the diode 15, and outputs the output voltage Ve of the charge / discharge circuit 11 shown in FIG. 3 (C).
Are supplied to the buffer circuit 18 of the power supply / interruption circuit 12.

The input voltage of the buffer circuit 18 is at the threshold level Vs.
When it exceeds, the power is turned on and the power supply voltage Va is supplied to the encoder section 2 as shown in FIG. The output voltage Vb shown in FIG. 3 (D) of the power supply / interruption circuit 12 is applied to the reset unit 6, and the capacitor 20 is charged through the charging resistor 19 of the reset unit 6 to reset the reset unit 6. The voltage Vc rises with a predetermined time constant defined by the charging resistor 19 and the capacitor 20, whereby the microcomputer of the encoder section 2 starts operating.

After the power supply voltage Vb to the encoder unit 2 shown in FIG. 3 (D) rises, the reset voltage Vc rises with a predetermined time constant as shown in FIG. 3 (E). The microcomputer of the encoder unit 2 is set surely and the operation is started.

Next, when the battery of the power supply unit 4 is exhausted and the power supply voltage Va drops to a predetermined level or less of the voltage detection circuit 10, the detection voltage Vd
Is stopped and the output of the voltage detection circuit 10 becomes low level. The voltage detection IC 13 of the voltage detection circuit 10 has a hysteresis Vh, as shown in FIG. 3 (B). When the output of the voltage detection circuit 10 becomes low level, the electric charge of the capacitor 20 of the reset part 6 is immediately discharged through the diode 21, and the reset voltage Vc of the reset part 6 becomes low level, whereby the encoder Some microcomputers are reset and stop operating.

Further, since the output of the voltage detection circuit 10 becomes low level, the charge of the capacitor 17 of the charging / discharging circuit 11 becomes the discharge resistance.
Since it is discharged through 16, the output voltage Ve of the charge / discharge circuit 11
Decreases with a time constant determined by the capacitor 17 and the discharge resistance 16. When the input voltage of the buffer circuit 18 of the power supply / interruption circuit 12 falls below the threshold level Vs due to the decrease of the output voltage Ve, the power is turned off and the power supply voltage of the encoder unit 2 becomes as shown in FIG. 3 (D). Be cut off.

Thus, after the reset voltage Ve shown in FIG. 3 (E) falls and the microcomputer of the encoder section 2 is reset and the operation is surely stopped, as shown in FIG. 3 (D), Power supply voltage to encoder unit 2
Since the supply of Vb is cut off, the encoder section 2 is prevented from malfunctioning as in the conventional example.

Although the above embodiments have been described by applying to the memory remote controller, the present invention is not limited to the memory remote controller and can be applied to other remote controller transmitters as well.

<Advantages of the Invention> As described above, according to the present invention, the supply of the power supply voltage to the encoder unit is cut off after the reset voltage falls and the microcomputer of the encoder unit surely stops its operation. Therefore, as in the conventional example, it is possible to prevent the microcomputer of the encoder section from malfunctioning when the power supply voltage drops.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG.
FIG. 3 is a circuit diagram of the power switch section and reset section in the figure, FIG. 3 is a waveform diagram showing the voltage change of each section in FIG. 2, FIG. 4 is a block diagram of a conventional example, and FIG. 5 is a power switch section in FIG. FIG. 6 is a waveform diagram showing a voltage change in each part of FIG. 5, and FIG. 7 is a waveform diagram showing a fall of the power supply voltage and the reset voltage to the conventional encoder part. 2 …… Encoder part (microcomputer), 5 ……
Power switch, 6 ... Reset, 10 ... Voltage detection circuit, 11 ... Charging / discharging circuit, 12 ... Power supply / interruption circuit.

Claims (1)

[Scope of utility model registration request] 1. A battery power source, a microcomputer constituting an encoder section, a power switch section for controlling the supply / interruption of a power source voltage from the battery power source to the microcomputer, and an output voltage of the power switch section. Based on the above, in the remote control transmitter including a reset unit that outputs a reset voltage to the microcomputer, the power supply switch unit includes a voltage detection circuit that outputs a detection voltage when the power supply voltage exceeds a predetermined level. , A charging / discharging circuit that is charged by this detection voltage and discharges with a predetermined time constant in response to a decrease in the detection voltage, and based on the output voltage of this charging / discharging circuit, of the power supply voltage to the microcomputer. A power supply / interruption circuit for performing power supply / interruption, wherein the reset unit supplies the power While being charged with a predetermined time constant by the output voltage of the cutoff circuit, the remote control transmitter, characterized in that it consists of charging and discharging circuit to immediately discharge in response to a decrease of the detection voltage.