JPH0141043B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal adjustment method that can be used as a variable attenuator that attenuates and outputs an input signal.

An object of the present invention is to provide a signal adjustment method using a piezoelectric element.

The present invention will be explained below with reference to Examples.

The figure is a block diagram used in the method of the invention.

Reference numeral 1 denotes an operating arm rotatably mounted in an operating box (not shown). The first
A piezoelectric element 2 , and a second piezoelectric element 3 facing the first piezoelectric element 2 with the operating arm 1 in between are fixed in the operation box. The outputs of the first and second piezoelectric elements are input to an adder 4. On the other hand, the output of the first piezoelectric element is input to an output detection circuit 5 that detects the presence or absence of the output of the first piezoelectric element.
The output of the adder 4 is applied to a voltage controlled oscillator 6, and the output of the voltage controlled oscillator 6 is applied as a count input to an up/down counter 7. Output detection circuit 5
The output is applied to the up-down counter 7 as an input for switching between up-counting and down-counting. The output of the up-down counter 7 is input to the digital-to-analog converter 8,
The output of the digital to analog converter 8 is applied to a voltage controlled attenuator 9 to which the input signal is applied to control its attenuation rate.

Note that CL is a clear signal applied to the up-down counter 7.

10 is a display device for displaying the output of the counter 7.

In this embodiment configured as described above, when the operating arm 1 is rotated clockwise, the second piezoelectric element 3 receives a force corresponding to the rotation angle of the operating arm 1, and outputs an output corresponding to the rotation angle. Generates voltage. This output voltage is applied to a voltage controlled oscillator 6 through an adder 4. In this case, since the first piezoelectric element is not generating an output, the output of the adder 4 depends only on the output of the second piezoelectric element 3. Therefore, the voltage controlled oscillator 6 generates an output with a frequency corresponding to the rotation angle of the operating arm 1. Further, the output detection circuit 5 is connected to the first piezoelectric element 2
Since no output is generated, the up/down counter 7 is set as a down counter. Therefore, updown counter 7
counts down the output of the voltage controlled oscillator 6,
The output count value of the up-down counter 7 decreases. Therefore, the voltage-controlled attenuator 9 reduces its resistance through the digital-to-analog converter 8 in accordance with the rotation angle of the operating arm 1, thereby reducing the degree of attenuation of the input signal.

On the other hand, when the operating arm 1 is rotated counterclockwise, the piezoelectric element 2 receives pressure from the operating arm 1.
An output corresponding to the rotation angle of the operating arm 1 is generated.
This output is applied to the voltage controlled oscillator 6 via the adder 4, and the voltage controlled oscillator 6 generates an output at a frequency corresponding to the rotation angle of the operating arm 1 in the counterclockwise direction. On the other hand, the output detection circuit 5 is connected to the first piezoelectric element 2
Since is generating an output, it generates an output and switches the up-down counter 7 to the up-counting operation example. Therefore, the output of the voltage controlled oscillator 6 is up-counted by the up-down counter 7, and the count output value of the up-down counter 7 increases. Therefore, the voltage-controlled attenuator 9 increases its resistance in accordance with the rotation angle of the operating arm 1 via the digital-to-analog converter 8, thereby increasing the degree of attenuation of the input signal.

As described above, according to the present invention, the input signal can be attenuated using the piezoelectric element in accordance with the rotation direction and rotation angle of the operating arm.

[Brief explanation of drawings]

The figure shows an example of a block diagram used in the method of the invention. 1... Operating arm, 2 and 3... First and second
piezoelectric element, 4... adder, 5... output detection circuit, 6... voltage controlled oscillator, 7... up/down counter, 8... digital analog converter, 9...
...voltage controlled attenuator.

Claims (1)

[Claims] 1. Rotating a rotatably mounted operating arm in one direction presses a first piezoelectric element, and rotating the operating arm in the other direction presses a second piezoelectric element to obtain an output; A voltage-controlled oscillator is controlled by a signal obtained by adding these outputs, and the presence or absence of the output of the first piezoelectric element is detected by an output detection circuit, and the output from the voltage-controlled oscillator is counted by an up-down counter; A signal adjustment characterized in that the counting direction is controlled by the output of the output detection circuit, and the output of the up-down counter is further converted into an analog signal, and the input signal of the voltage-controlled attenuator is attenuated by this analog signal and output. Method.