JPH0430286A - counting circuit - Google Patents

Abstract

PURPOSE:To correctly count the number of pieces of passing hard money by switching a reference level according to the results of a signal inputted from a metal sensor and the reference level. CONSTITUTION:When the value of a detection signal supplied from a variable reluctance sensor 2 is larger than the value of the reference signal supplied from a reference level switching circuit 3, a comparator 4 detects it, and generates a hard money detection signal, and supplies it to a one-shot multivibrator 5. The one-shot multivibrator 5 generates the '1' signal of pulse width T1 every time the hard money detection signal is supplied, and supplies it to a counter 6. Then, the counter 6 increases a count value every time the '1' signal is supplied from the one-shot multivibrator 5, and supplies this counted result to a display device 7, and the display device 7 displays it as the number of pieces of the passing hard money 8. Thus, the number of pieces of the passing hard money 8 can be correctly counted.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a counting circuit used in a counting device for counting coins, medals, etc.

(Prior art) In a counting device that counts coins, medals, etc., a microswitch equipped with an actuator, etc. is installed in the conveyance path of coins, etc., and the coins, etc. are moved through the conveyance path based on the on/off results of the microswitch. Counting the number of coins, etc.

However, such a mechanical counter has a problem in that it is unable to count coins at high speed due to poor responsiveness.

Therefore, as a method to solve such problems, a counting circuit using a variable reluctance type differential sensor has been developed.

FIG. 4 is a circuit diagram showing an example of such a counting circuit.

The counting circuit shown in this figure: an oscillation circuit +01, a variable reluctance sensor 102, a reference signal generation circuit 103,
It is equipped with a comparator 104, a one-shot multivibrator 105, a counter 106, and a display 107.
The presence or absence of passing O8 is detected, and this is counted to display the number of passing sheets on a display 107).

The oscillation circuit 101 has a preset period T.

The AC signal is configured to oscillate and generate an AC signal at a constant level, and this AC signal is sent to the variable reluctance sensor 1.
02 input terminals 102a and 102b.

The variable reluctance sensor 102 has input terminals 102a, 1
Primary coil +10 connected to 02b and output terminal 10
2c and 102d, and the primary coil is excited by the alternating current signal supplied from the oscillation circuit 101 to generate a magnetic field.
A coin 10 is placed near the secondary coil 11O and the secondary coil I11.
8 passes and the mutual inductance between the primary coil +10 and the secondary coil II+ changes according to the magnetic permeability of the coin 108, an electromotive force (detection signal) shown in FIG. 5 (a>) is generated in the secondary coil Ill. generates and converts this into comparator 1
04 non-inverting input terminal.

Further, as shown in FIG. 4, the reference signal generating circuit 103 generates a reference signal having a voltage value TH, which is lower than the output level when the coin 108 is detected by the variable reluctance sensor 102, and sends this to the inverted input of the comparator 104. Supply to the terminal.

The comparator 104 is the reference signal generating circuit 10.
When the value of the detection signal supplied from the variable reluctance sensor 102 is larger than the value of the reference signal supplied from the variable reluctance sensor 102, this is detected and the coin detection signal shown in FIG. 5(b) is generated and this is one-shot. It is supplied to the multivibrator 105.

The one-shot multivibrator 105 is a re-trigger type one-shot multivibrator with a time constant of 1, and generates an "l" signal with a pulse width T every time a coin detection signal is supplied from the FjM self-converter 104. and supplies it to the counter 106.

In this case, when the coin detection signal is continuously supplied from the comparator 104 within a time period T, the one-shot multi-by-break 105 stops being supplied from the time when the coin detection signal is supplied, as shown in FIG. 5(c). Time T1
A "1" signal is continuously generated and supplied to the counter 106 until the time period elapses.

The counter 106 operates as shown in FIG. 5(d) every time the one-shot multivibrator 105 supplies the "1" signal
The count value is incremented as shown in , and the count result is supplied to the display 107.

When the count result is supplied from the counter 106, the display +07 displays it as the number of passing coins +08.

By the way, in such a conventional counting circuit, depending on the material of the coin 108, etc., when one coin +08 passes, the waveform of the detection signal output from the variable reluctance sensor 102 may be as shown in No. 611(a). Due to the disturbance, the interval between the coin detection signals output from the comparator 104 may be longer than the time T as shown in FIG. 6(b).

At this time, as shown in FIG. 6(C), a plurality of "】" signals are output from the one-shot multi-by-break 105, the counter 106 is incremented as shown in FIG. 6(d), and the actual passage is displayed on the display. More values than the number of sheets are displayed.

(Object of the Invention) The present invention has been made to eliminate the above-mentioned conventional drawbacks, and even when the waveform of the detection signal output from the variable reluctance sensor is disturbed due to the material of the coin, etc., the coin The object of the present invention is to provide a counting circuit that can accurately count the number of passing sheets.

(Summary of the Invention) In order to solve the above problems, in a counting circuit according to the present invention, a counting circuit that detects passage of a metal object by a metal sensor and counts the number of passing metal objects, includes a a level discriminator that discriminates the level of the signal by comparing the output signal with a reference level; a reference level switching section that can learn the reference level of the level discriminator according to the discrimination result of the level discriminator; The present invention is characterized by comprising a counting section that performs a counting operation based on the discrimination result of the level discriminating section.

(Examples) Hereinafter, the present invention will be described in detail based on illustrated examples.

FIG. 1 is a block diagram showing one embodiment of the present invention.

The counting circuit shown in this figure includes an oscillation circuit 1, a variable reluctance sensor 2, a reference level switching circuit 3, a comparator 4, a one-shot multivibrator 5, a counter 6, and an indicator 7. The reluctance sensor 2 detects whether or not the coins 8 have passed, and the number is counted and the number of coins passed is displayed on the display 7.

The oscillation circuit 1 has a preset period T. It is configured to oscillate at a constant level to generate an alternating current signal.
This AC signal is input to the input terminal 2 of the variable reluctance sensor 2.
a, 2b.

The variable reluctance sensor 2 includes a primary coil 10 connected to input terminals 2a and 2b, and a secondary coil 11 connected to output terminals 2c and 2d. The coils are excited to generate a magnetic field, and these secondary coils 10 and 11
When the coin 8 passes near the coin 8 and the mutual inductance between the primary coil 10 and the secondary coil 11 changes according to the magnetic permeability of the coin 8, an electromotive force (detection signal) is generated in the secondary coil 11. and supplies this to the non-inverting input terminal of the comparator 4.

The reference level switching circuit 3 also includes a first reference signal generator 12 that generates a reference signal with a voltage value TH, and a first reference signal generator 12 that generates a reference signal with a voltage value THI (
However, the second reference signal generator 13 that generates a reference signal of TH,<TH,) and the first and second reference signal generators I
2.13, and when the one-shot multivibrator 5 outputs a "0" signal, the switch 15 selects the first reference signal output from the first reference signal generator 12. This is selected and supplied as a reference signal to the inverting input terminal of the comparator 4, and also from the one-shot multi-by-break 5.
When the I'' signal is being output, the second reference signal output from the second reference signal generator I3 is selected by the switch 5 and is supplied to the inverting input terminal of the comparator 4 as a reference signal.

A comparator 4 detects when the value of the detection signal supplied from the variable reluctance sensor 2 is greater than the value of the reference signal supplied from the reference level switching circuit 3, generates a coin detection signal, and switches it to one. Supply to shot multi-by break 5.

The one-shot multivibrator 5 is a re-trigger type one-shot multivibrator having a time constant T1, and generates a "1" signal with a pulse width T every time the coin detection signal is supplied from the comparator 4. This is supplied to the counter 6.

In this case, when the coin pressure detection signal is continuously supplied from the comparator 4 within the time T1, the one-shot multivibrator 5 maintains "l" from the time the coin pressure detection signal is supplied until the time T1 elapses after it is no longer supplied. A signal is continuously generated and supplied to the counter 6.

Counter 6 is iH one-shot multivibrator 5
Every time a "1-" signal is supplied from , the count value is incremented and the count result is supplied to the display 7.

When the count result is supplied from the counter 6, the display 7 displays it as the number of coins 8 that have passed.

Next, the operation of this embodiment will be explained with reference to FIG.

First, when the variable reluctance sensor 2 does not detect the coin 8 and the comparator 4 does not output a coin detection signal, the one-shot multivibrator 5 outputs a 10'' signal.

As a result, the switch 14 of the reference level switching circuit 3 selects the first reference signal output from the first reference signal generator 12 and supplies it to the inverting input terminal of the comparator 4 as a reference signal.

When the passage of the coin 8 is detected by the variable reluctance sensor 2, a detection signal is output from the variable reluctance sensor 2 as shown in FIG. 2(a), and this is the value TH of the first reference signal.

When the value exceeds 0, a coin detection signal is output from the converter 4 as shown in FIG. 2(b).

As a result, the one-shot multivibrator 5 is triggered to output the "l" signal as shown in FIG. 2(d), and the switch 15 of the reference level switching circuit 3 is switched by this "1'" signal. The second reference signal output from the second reference signal generator 13 is selected, and the value of the reference signal supplied to the inverting input terminal of the humpator 4 is lowered as shown in FIG. 2(c).

As a result, even if the detection signal output from the variable reluctance sensor 2 is disturbed due to the material of the coin 8, the one-shot multivibrator 5 is triggered every time T0, and the one-shot multivibrator 5 continuously transmits "
1” signal is output.

When the coin 8 is no longer detected by the variable υ roughtance sensor 2 and a time T has elapsed since the coin detection signal is no longer output from the comparator 4, the one-shot multi-by-break 5 outputs the 'l'' signal. As a result, the counter 6 increments the count value and increases the number of passing coins 8 displayed on the display 7 by "1".

At this time, the switch 15 of the reference level switching circuit 3 selects the first reference signal output from the first reference signal generator J2 and supplies it as a reference signal to the inverting input terminal of the comparator 4 to start the circuit. return to the state of

As described above, in this embodiment, the reference level of the comparator 4 is set to the value TH until the value of the detection signal outputted from the variable reluctance sensor 2 becomes large to a certain extent to prevent malfunctions due to noise etc. When the value exceeds the value TH, the reference level of the comparator 4 is lowered to the value TH□, so the waveform of the detection signal output from the variable reluctance sensor 2 is distorted depending on the material of the coin 8, etc. Even at times, the number of passing coins 8 can be accurately counted.

FIG. 3 is a small block diagram of another embodiment of the counting circuit according to the invention. In this figure, parts corresponding to those in FIG. 1 are given the same reference numerals.

The counting circuit shown in this figure differs from the circuit shown in FIG. 1 in that a D-type flip-flop 20 and a microprocessor 21 are provided in place of the counter 6.

Each time the value of the AC signal output from the oscillation circuit 1 exceeds a positive predetermined value, the D-type flip-flop 20 takes in the output of the one-shot multi-by-break 5 through the input terminal and outputs it from the set output terminal Q. and supplies it to the microprocessor 21.

Therefore, when the one-shot multivibrator 5 continuously outputs the "1-" signal, the D-type flip-flop 20 continuously outputs the "1" signal from the set output terminal Q and transmits it to the microprocessor 21. supply to.

The microprocessor 21 is a flip-flop 2 of the above type.
When the 0 to "l" signal is not supplied, the switch I5 of the reference level switching circuit 3 is controlled to select the first reference signal output from the first reference signal generator 12, and this is used as the reference signal to the comparator. It is supplied to the inverting input terminal of No. 4. When a "1" signal is supplied from the flip-flop 20, the microprocessor 21
The switch 15 of the reference level switching circuit 3 is switched in synchronization with the rise of the second reference signal generator! After selecting the second reference signal output from the one-shot multivibrator 3 and supplying it as a reference signal to the inverting input terminal of the comparator 4, when the "1" signal is no longer supplied from the one-shot multivibrator 5, the counter The number is incremented and the number of passing coins 8 displayed on the display 7 is "!"
“Increase only.

Even with this configuration, the coin 8
Even when the waveform of the detection signal output from the variable reluctance sensor 2 is disturbed due to the material of the variable reluctance sensor 2, the number of passing coins 8 can be accurately counted.

(Effects of the Invention) As explained above, according to the present invention, even when the waveform of the detection signal output from the variable reluctance sensor is disturbed due to the material of the coin, etc., it is possible to accurately count the number of passing coins. can.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the counting circuit according to the present invention, FIGS. 2(a) to (e) are waveform diagrams and timing diagrams each illustrating an example of the operation of the same embodiment, and FIG. 3 is a block diagram of the present invention. A block diagram showing another embodiment of the counting circuit according to the invention, FIG. 4 is a block diagram showing an example of a conventionally known counting circuit, and FIGS. 5(a) to (d) are each shown in FIG. 4. A waveform diagram and a timing diagram explaining an example of the operation of the counting circuit, Fig. 6 (
a) to (d) are a waveform diagram and a timing diagram respectively illustrating an example of the operation of the counting circuit shown in FIG. 4; 2... Metal sensor (variable reluctance sensor), 3.
-Reference level switching section (reference level switching circuit), 4...
・Level discriminator (converter), 5... One-shot multivibrator, 6... Counter (counter)

Claims (1)

[Claims] (1) In a counting circuit that detects the passing of a metal object by a metal sensor and counts the number of passing metal objects, a level that discriminates the level of the signal by comparing the signal output from the metal sensor with a reference level. A discrimination section, a reference level switching section that switches the reference level of the level discrimination section according to the discrimination result of the level discrimination section, and a counting section that performs a counting operation based on the discrimination result of the level discrimination section. A counting circuit featuring: