JPH0321450Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] This invention relates to a numerical value input device for a recorder used to write numerical values such as date and time on recording paper. [Technical background of the invention] When recording the waveform of a signal under test, it is convenient to record the measurement date, measurement time, and other numerical values on recording paper along with the input waveform, etc., for later analysis of the data. It is. As such numerical input means, one having a numeric keypad structure in which keys from 0 to 9 are arranged is commonly used. However, when using a numeric keypad, many parts are required and the circuit configuration is complicated. Although it is good if there are many opportunities to input numerical values, it is not worth the cost if it is used infrequently. [Purpose of the invention] This invention was made in view of the conventional circumstances mentioned above, and its purpose was to
To provide a numerical value input device for a recorder that allows desired numerical values to be input with simple operations. [Examples] Hereinafter, this invention will be described in detail with reference to embodiments shown in the accompanying drawings. As illustrated in FIG. 1, this recorder includes an input circuit 1 for inputting a signal under measurement, an offset voltage generation circuit 2 for superimposing a predetermined offset voltage on the output of the input circuit 1, and an offset voltage generating circuit 2 for superimposing a predetermined offset voltage on the output of the input circuit 1. For example, the measured signal analog signal on which
A/D converter 3 that converts into a bit digital signal
and a microcomputer 4, and a central processing unit (CPU) 5 of the microcomputer 4.
Based on the digital signal output from the A/D converter 3, the recording head 7, which is comprised of, for example, a discharge multi-needle electrode or a thermal head, is driven to record the input waveform on recording paper (not shown). This invention has a switch means 8 that is operated when inputting a numerical value, and by turning on this switch means 8 and adjusting the offset voltage,
It is possible to input the desired numerical value.
That is, when inputting numerical values, nothing is connected to the input circuit 1 and the input of the signal to be measured is cut off, and only the offset voltage from the offset voltage generation circuit 2 is applied to the A/D converter 3. Then, when the switch means 8 is turned on, the CPU 5 of the microcomputer 4 executes the A/D according to the calculation program stored in the memory 6.
A corresponding numerical value from 0 to 9 is obtained from the output value of the D converter 3, and the numerical signal is outputted to the recording head 7. Here, the offset voltage generation circuit 2 outputs an offset voltage in the range of 0 to 4V by operating a rotary switch etc., and the relationship between the corresponding output value of the A/D converter 3 is as shown in the table below. Assuming that the setting is set, the CPU 5 performs the calculation (A/D output value + 8)/25 as shown in the operation flowchart in Figure 2, and calculates the offset voltage by rounding down to the decimal point. Get the corresponding numerical value. in this case,
According to the relationship shown in the table below, there will be a situation where the above calculated value becomes 10 or more, but in that case, the value will be treated as 9. In this example, a constant value of 8 is added to the A/D output value, but this is because the offset voltage and A/D output value are set in the relationship shown in the table below. You can choose an appropriate constant value depending on how you set it.

[Table] By adjusting the offset voltage as described above, a corresponding value from 0 to 9 can be obtained. For example, to remove noise caused by fluctuations in the power supply, you can do the following. Bye. That is, while maximizing the measurement range and minimizing the gain of the amplifier, the output value of the A/D converter 3 is read several tens to hundreds of times, and the same calculation as above is performed using the average value. All you have to do is In this case, the time to read the output value of the A/D is 100 ms, which is the least common multiple of 50 Hz (20 ms) and 60 Hz (16.67 ms), or an integral multiple thereof. For reference, FIG. 3 shows an operation flowchart of the CPU 5 when noise is removed in this manner. Note that, unlike the above embodiment, the output value of the A/D converter 3 is preset in the CPU 5.
A discriminating circuit is formed for discriminating which of the ranks it belongs to, and memory cells storing numerical values from 0 to 9 corresponding to those ranks are prepared in the memory 6, and the A/D conversion value by the above discriminating circuit is formed. Numerical values may be read from the memory cells according to the ranking. Further, a switch is provided at the output end of the input circuit 1, and the switch interlocks with the switch means 8, and when the switch means 8 is turned on, the output of the input circuit 1 to the A/D converter 3 is automatically turned off. You can also do that. [Effects] As is clear from the above description of the embodiment, according to this invention, the offset voltage output from the existing offset voltage generation circuit 2 can be adjusted simply by using, for example, a rotary switch, without using a numeric keypad. Numerical values such as date and time can be entered through operations.

[Brief explanation of drawings]

Figure 1 is a block diagram of one embodiment of this invention, and Figures 2 and 3 are shown in Figure 1.
This is a flowchart of CPU operation. In the figure, 1 is an input circuit, 2 is an offset voltage generation circuit, 3 is an A/D converter, 4 is a microcomputer, 5 is a CPU, 6 is a memory, 7 is a recording head,
8 is a switch means.

Claims (1)

[Claims for Utility Model Registration] (1) An input circuit for a signal under test, an offset voltage generation circuit for superimposing a predetermined offset voltage on the signal under test, and an analog signal output from each of these circuits into a digital signal. Convert A/
a D converter, and drives a recording head based on a digital signal from the A/D converter to record the input waveform of the signal to be measured on recording paper, when the input circuit is in an OFF state. From the A/D conversion value of the offset voltage output from the offset voltage generation circuit, the corresponding numerical value 0 to
9, and a switch for activating the same numerical value selection means, and by changing the offset voltage, the offset can be changed via the numerical value selection means. A numerical input device for a recorder, characterized in that it obtains a numerical signal corresponding to voltage. (2) In claim (1) for utility model registration, the numerical value selection means selects M/10, where the output value range of the A/D converter is 0 to M, and each output value is X. (However, the decimal point is rounded down) as the denominator, (X+k) is the numerator (k is a constant), and the division is performed, and the quotient is rounded up or down to obtain the numerical value corresponding to the offset voltage. A numerical input device for a recorder. (3) In claim (1) for utility model registration, the numerical value selection means includes a circuit that determines whether the output value of the A/D converter falls within one of ten preset ranks; and a memory storing numerical values from 0 to 9 corresponding to each rank, and the record is characterized in that the corresponding numerical values are read out from the memory as the output values of the A/D converter are classified into ranks. A numerical input device in a meter.