JPS6349920A - Switch input device - Google Patents

Abstract

PURPOSE:To reduce the number of I/O ports by determining a time constant based on the number of times of ON of each switch by a resistor connected to each switch and a capacitor and electrostatically charging the capacitor based on the time constant. CONSTITUTION:An amplifier 4 is connected to an output port 2 of a microcomputer 1, switches 6, 8, 10 for drive, stop and operation of a four-way valve or the like to control the apparatuses of an air conditioner, a serial circuit of resistors 7, 9, 11 for determining time constants and a diode 12 are connected between the output side of the amplifier 4 and the plus side of a comparator 5 and the comparator 5 is connected to an input port 3 of the microcomputer 1. A capacitor 15 is connected between the plus side of the comparator 5 and GRN to determine a time constant selectively by the capacitor 15 and said resistors 7, 9, 11. When the microcomputer 1 outputs an H level signal to its output port 2, the capacitor 15 is charged based on the time constant determined by a selected ON switch and a resistor. The comparator 5 integrates times required up to a prescribed voltage and discriminates the ON switch.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a switch input device for an air conditioner or the like.

2. Description of the Related Art Conventionally, for example, a switch input device uses a microcomputer (hereinafter referred to as a microcomputer) 18 as shown in FIG.
outputs a scan signal through the output port 17, and displays the ○N and OFF states of each device control switch 19 connected to the output port 1 on the microcomputer 16 side, corresponding to the number of each switch. The data is transmitted to several input ports 18 and processed as switch input data.

Problems to be Solved by the Invention In such a conventional configuration, as the number of switch inputs increases, such as in the air conditioner compressor, four-way valve, solenoid valve, etc., the number of input/output ports 18 of the microcomputer and the software increase. However, this has resulted in problems such as increased cost and increased size of the substrate.

The present invention solves the above-mentioned conventional problems and aims to enable connection of many switch inputs with a small number of input/output ports of a microcomputer.

Means for Solving the Problem In order to solve this problem, the present invention provides switches for controlling air conditioner equipment connected to an output port on the microcomputer side via an amplifier, and each switch for controlling the air conditioner. A capacitor that determines the time constant based on the combined resistance value of each resistor connected to the positive side of the comparator, a discharge diode connected to the amplifier side provided at the output port, and a standard that divides the CC voltage. and a circuit that connects a voltage to the negative side of the comparator and inputs it to the microcomputer side.

Effect With this configuration, from the time the microcontroller outputs an H level signal to the output port, the comparator compares the charging voltage due to the time constant of the resistor and capacitor connected to the output port with the reference voltage, and calculates the charging voltage. When becomes larger, the output of the comparator is inverted, and the microcomputer integrates the time until this charging voltage is reached, and the microcomputer uses this time to determine the switch input.

EXAMPLE An example of the present invention will be described below with reference to FIG. Reference numeral 1 designates a microphone convex computer (hereinafter referred to as a microcomputer), and an amplifier 4 that performs all amplification is connected to its output port 2, and an air conditioner is connected between the output side of the amplifier 4 and the positive side of the comparator 5. Connect a switch 6.8.10 for starting/stopping the equipment and operating a four-way valve, etc., a series circuit of resistors 7 and 9.11 and a diode 12 for determining the time constant, and a comparator. 6 is connected to the input port 3 of the microcomputer 1. A reference voltage obtained by dividing vcc by resistors 13 and 14 is applied to the negative side of the comparator 6. A capacitor 16 is connected between the positive side of the comparator 6 and GND, and each switch 6.8.1
The time constant is determined by the number of ON [, 0].

Note that the diode 12 is connected to the output port 2 from the microcomputer 1.
When the L level is output from the capacitor 12
The function is such that the electric charge that has been charged in the amplifier 4 is discharged to the amplifier 4 side.

In the above configuration, if an L level is output from the microcomputer 1 to the output port 2, and the amplifier 4 also outputs an L level, the charge stored in the capacitor 16 will be rapidly discharged via the diode 12. The voltage between the GND of the capacitor 16 and the positive side of the comparator 6 becomes 0. Next, when the microcomputer 1 outputs an H level through all of the output ports 2, this output is received by the amplifier 4 and outputs an H level, and in this H level output state, each of the switches 6.8.10. The resistance values of the resistors 7 and 9.11 change depending on whether they are 0NiOFF or not, and the combined resistance changes. For example, when switch 6 and switch 1o are in the ON state, the combined resistance of resistor 7 and resistor 11 is determined, and a time constant is determined between these two resistors 7 and 11 and capacitor 15. The charging time changes, this charging voltage is input to the positive side of the comparator 6, and the microcomputer 1 counts the time up to this point. on the other hand,
The reference voltage of the distribution voltage generated by the resistor 13 and the resistor 14 is input to the negative side of the comparator 5 and compared with the charging voltage by the comparator 6. Then, the output of comparator 6 is inverted, and input port 3 becomes
At the same time as the signal is transmitted to the microcomputer 1 through the signal, the time currant stops. Based on this count value, the microcomputer 1 determines which switch among the switches 6, 8, and 10 is ON or OFF.

Effects of the Invention As is clear from the description of the embodiments described above, the present invention provides a resistor connected to each switch and a capacitor connected to the GND side. Since a constant is determined and this time constant is used to charge the battery, even if the number of switches increases, the microcontroller only needs one input port and one output port. , the software can be easily configured and the cost can be reduced.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a switch input device for an air conditioner according to an embodiment of the present invention, and FIG. 2 is a circuit diagram of a conventional switch input device for an air conditioner. 1...Microcomputer-14...
・Amplifier, 6... Comparator, 6, 8.10... Mountain switch, 7°9.11... Resistor, 12.
·····diode.

Claims (1)

[Claims] Each switch for controlling the air conditioner is connected to the output port of the microcomputer via an amplifier, each resistor is connected to the positive side of the comparator, and each of the resistors is connected to the positive side of the comparator. A capacitor connected between the GND side and determining the time constant based on the combined resistance value of each of the resistors, a discharge diode connected to the amplifier side provided at the output port, and a reference voltage obtained by dividing the V_c_c voltage. A switch input device comprising: a circuit connected to the negative side of the comparator and input to the microcomputer side.