JPH04118529U - Input switching circuit - Google Patents

Abstract

(57) [Summary] [Purpose] To reach the power ON state without preparing a separate power source and to enable setting to a desired switching position set in advance. [Structure] The switching position of the input selector switch, which does not memorize the switching position when the power is turned off, is held when the power is turned on by a holding switch that works with this input switching switch. By setting the input changeover switch to the switching position when the power is turned on before the power is turned off based on the set position of the switch, it is possible to set the input changeover switch to the desired switching position.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to input switching circuits, especially when changing from a power OFF state to a power ON state. The input switching circuit maintains the switching position before the power is turned off even when the power is turned off. related.

0002

[Conventional technology]

Select the desired input terminal from among multiple input terminals, and input to the selected input terminal. An example of an input switching circuit for extracting a force signal is shown in FIG. Input terminals IN1 and IN2 are connected to selector switch 1 (usually a semiconductor chip such as C-MOS). are connected to the corresponding input terminals 11 and 12 of the external For example, an audio signal to one of the input terminals is selectively output by the switching control signal from be done. The signal to the input terminal selected by selector switch 1 is amplified by amplifier 3. After that, audio is played back from the speaker 4. Also, input to input terminals IN1 and IN2 One of the force signals is selected by the changeover switch 2 and sent to the output terminal OUT. be done. The changeover control signal for changeover switch 1 is the input changeover key (switch) set by the user. Determined by the operation status of keys 61 and 62 of (for speaker output) 6, The operation status information is sent to the CPU 52 via the input port 51 of the microcomputer 5. The switching control is performed according to the processing procedure program input to the ROM 54 and stored in the ROM54. The control signal is sent to the changeover switch 1 via the output port 55 using the RAM 53. be done.

0003

[Problem that the idea aims to solve]

As mentioned above, conventional input switching circuits use the switching operation of semiconductor switches to Selecting and switching power terminals. However, when the semiconductor switch is used as a selector switch, when the power is turned off, , the setting contents in the ON state are erased and the state becomes undefined. Therefore, with the power on Even if you set the input switching position, if the power is turned off, the power will be turned on. After that, the switching position must be set again. In addition, in order to memorize the switching position of the power ON state with a semiconductor switch, it is necessary to A power source must be provided for the conductor switch, which poses cost and configuration issues. occurs.

0004 Therefore, the purpose of this invention is to enable the power to be turned on without having to prepare a separate power source. Both input switches allow setting to a preset desired switching position. The objective is to provide an exchange circuit.

[0005]

[Means to solve the problem]

In order to solve the above-mentioned problem, the input switching circuit according to this invention is An input switch with an input selector switch that does not remember the switching position when the power is turned off. In the switching circuit, Set the input selector switch to the same position as when the power is turned on. A hold selector switch that maintains the set position even when the power is turned off. In preparation, the set position of the holding selector switch when the power is turned on after the power is turned off. the input selector switch is configured to set the input selector switch to the selector position based on It is.

[0006]

[Effect]

In this design, the input selector switch does not memorize the switching position when the power is turned off. The switching position when the power is turned on is maintained by a switching switch that works with this input switching switch. After the power is turned off, this hold selector switch is held when the power is turned on. When the input selector switch is turned on based on the set position of the By setting it to the switching position, you can set it to the desired switching position. possible.

[0007]

【Example】 Next, this invention will be explained with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an input switching circuit according to this invention. In Figure 1, components given the same symbols as in Figure 3 have the same functions as in Figure 3. It is a component that The input audio signal to input terminal IN1 or IN2 is One of input terminals 11 and 12 is selected by circuit 1 and amplified by amplifier 3. After that, the reproduced sound is output from the speaker 4. The operation status of the keys 61 and 62 of the input switching key 6 is determined by the input of the microcomputer 5. The switching control signal input to the power port and the switching control signal to the switching switch 1 is sent to the microprocessor 5. is supplied from the output port 55 of.

[0008] In this embodiment, in conjunction with the switching of terminals 21 and 22 of changeover switch 2, the terminal A changeover switch 7 is provided to set the switching state to 71 and 72. Cut The setting state of the switching switch 7 is input to the input port 51 of the microcomputer 5. It is. Therefore, even if the setting state of selector switch 2 when the power is turned on is when the power is turned off, Since the settings are stored and set in the changeover switch 7, the microcomputer 5 selects the relevant switch. When the setting position information of switch 7 is read and the power is turned on from OFF, The changeover switch 1 made of a semiconductor switch can be set to the state before being turned off.

[0009] In other words, for example, a timer function can be used to turn on the power at a desired time and turn on the power at the desired time. When you want to output the input from speaker 4, set switch 2 to the desired position. Then, the position is determined by the position information of the switch 7 that is linked with the changeover switch 2. The information is supplied to the microcomputer 5 as information. Power is turned on by timer operation Then, the microcomputer 5 outputs the semiconductor switch 1 via the output port 55. selects a switching control signal and sends the signal to a predetermined input terminal through amplifier 3. Send to peaker 4.

0010 FIG. 2 shows a flowchart of the operational processing procedure of the embodiment shown in FIG. It is. First, after initialization (step S1), the switch 7 is connected to the terminal 71. It is determined whether the terminal is set to the terminal 71 side (step S2). If so, switch 1 is set to the 11 side (step S6). Step S2 smell If it is determined that it is not set to the terminal 71 side, switch 1 is set to the terminal 12 side. settings (step S3). After the processing in step S3 and step S6, is the key 61 of switch 6 pressed? Determine whether or not it is pressed (step S4), and if it is pressed, set switch 1 to terminal 11 side. (step S7), and then, or if key 61 is not pressed, press the switch. It is determined whether or not the key 62 of No. 6 has been pressed (step S5), and if it has been pressed, the After setting switch 1 to terminal 12 side (step S8), return to step S4. If the key 62 is not pressed, the process similarly returns to step S4. Furthermore, this invention can also be used to switch the input of a tuner, etc. using a timer. , easy to use.

0012

[Effect of the idea]

As explained above, the input switching circuit according to this invention It uses a microcomputer, so there is no need to install a separate power supply, and it is easy to compare. With a simple configuration, the changeover switch position before turning off the power can be set when turning on the power. Ru.

[Brief explanation of drawings]

FIG. 1 is a configuration block diagram showing one embodiment of an input switching circuit according to the invention.

FIG. 2 is a flowchart showing an operation processing procedure in the embodiment of FIG. 1;

FIG. 3 is a configuration block diagram of a conventional input switching circuit.

[Explanation of symbols]

1, 2, 7 changeover switch 3 Amplifier 4 Speaker 5 Microcomputer 6 Input selection key

Claims (1)

[Scope of utility model registration request] In an input switching circuit having an input selection switch that does not memorize the switching position when the power is turned off, a holding selection switch is set to the same position as the switching position of the input selection switch when the power is turned on, and maintains the set position even when the power is turned off. An input switching circuit, characterized in that the input switching circuit is set to the switching position based on the set position of the holding switching switch when the power is turned on after the power is turned off.