JPS5856211B2 - touch switch device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a touch switch device.

A touch switch device is generally defined as a switch for the purpose of limit control that detects mechanical contact of a detection object and performs switching.

The operating principles of this touch switch device include a method that uses the ground potential of the human body, a method that uses the earth capacitance of the contact body, and a method that uses a pressure-sensitive element. A touch switch device is also known in which a portion of the touch switch operates as a current path.

In the method that uses the earth capacitance of a contacting object, the oscillation condition of the oscillation circuit is either satisfied or not depending on whether or not the body parts are in contact, and the presence or absence of contact is detected based on the oscillation output. be.

Specifically, this type of touch switch device requires an oscillation circuit that includes a coil (inductance L), such as a Colpitts oscillator, and as a result, sensitivity decreases at high temperatures and productivity is low. It has the disadvantage of being costly.

In view of the drawbacks of the above-mentioned method using the earth's capacity, this invention
The purpose of the present invention is to provide a low-cost touch switch device with a simple circuit configuration, high reliability, and high reliability.

The touch switch device according to the present invention includes a pulse oscillator, two transmission paths for transmitting the pulse output, each comprising a resistor and a capacitor, and a contact electrode connected to one of the transmission paths. The resistance of each transmission path and the time constant of the capacitor are set so that the phase of the pulse transmitted through the two transmission paths is reversed depending on whether or not there is a connection between the ground capacitance due to contact of the body part with the Since it is equipped with a Noritsubu flop that applies pulses transmitted through two transmission lines to each of two input terminals, there is no need to configure an oscillation circuit including a coil, and the circuit configuration is simple. is unaffected and is highly reliable and inexpensive.

Further, by changing the time constants of the resistances and capacitors of the two transmission lines, the delay time can be varied, so the sensitivity of the switch can be adjusted.

Furthermore, since the flip-flop 70 knob has the function of phase discrimination and holding the discrimination result, this flip-flop output can drive a relay, etc., and a contact output can be obtained from this relay as a touch output. .

Since the flip-flop serves two functions in this way, the circuit configuration becomes simple.

Embodiments of the present invention will be described below with reference to the drawings.

In Figure 1, NAND used as an inverter
Gate t-1i, i2, resistor 13.14 and capacitor 15
A pulse oscillator 1 is constructed from these.

The pulses output from this pulse oscillator 1 are transmitted through the transmission line 2.
, 3, respectively, to a delay flip-flop (D-flip-flop) 50 input terminal D and a clock pulse input terminal CP.

The transmission lines 2 and 3 each include a resistor 2L31 that equivalently includes the output resistance of the oscillator 1, and a capacitor 2 that equivalently includes the leakage capacitance of the transmission line and the D-flip-flop 5.
2.32.

A contact tank 42 is connected to the transmission line 2 via a capacitor 41 .

The D-flip-flop 5 is composed of a C-MOS-IC and the like.

The pulse transfer functions of the transmission lines 2 and 3 are respectively R1, R2 is the value C1 of the resistors 21 and 31, C2 is the value S of the capacitor 22.32, and S is expressed as a parameter for Laplace transform, and each pulse arrival delay time T1
, T3 are determined by the R1C1 button and R2C2, respectively.

Here, if the constants of each transmission line are set as R1C1<R2C2, the pulse reaching the input terminal of the D-flip-flop 50 connected to the ends of transmission lines 2 and 3 will be as shown in Figure 2. The pulse that reaches the input terminal CP is delayed by the time T1, as shown in Figure 2C, and becomes T1<T3, so that the signal input to the terminal CP is input to the terminal CP. The output of the D flip-flop 5 becomes logic "1".

When a body part comes into contact with the contact tank 42, the ground resistance 43 and the ground capacitance 44 are equivalently connected to the transmission line 2.

Here, if the value of the ground-to-ground resistance 43 is RM, the value of the ground-to-ground capacitance 44 is CM, and the value of the capacitor 41 is C3, then C3
) CM, R1>>RM, so the pulse transfer function of the transmission line 2 is expressed by.

Here, by setting C1+CM>C2, the delay time T2 (determined by R1(C1+CM)) at this time can be made larger than the delay time T3, and therefore, as shown in FIG. The signal input to the
The signal input to the input terminal CP (shown in FIG. 3C) lags behind the signal input to the input terminal CP (shown in FIG. 3C), and the output of the flip-flop 5 becomes logic "0".

In this way, depending on the presence or absence of a capacitive connection between the earth and the earth due to contact between body parts, the delay time of one transmission line 2 can be changed to that of the other transmission line 3.
The delay time can be made long or short, and the flip-flop 5 can be inverted.

If the magnetic relay is driven once by the output of the flip-flop 5, a touch output is obtained as a contact output signal.

In this case, since the delay time can be varied by changing the time constants of the two transmission lines 2 and 30, the sensitivity of the switch can be adjusted.

By changing the resistance value of resistor 31, R2,
Since the delay time T3 (offset delay time) of the transmission line 3 determined by C2 can be varied, it is possible to adjust the sensitivity of the switch.

Also, instead of the D-flip-flop 50, two NO
It is advantageous in terms of cost to use an RS flip-flop composed of an R gate or the like.

This touch switch device can be used for motor control of electric pachinko game machines, automatic stop of electric fans, etc.

In other words, in the case of an electric pachinko game machine, it is configured so that the game cannot be played unless the player touches the contact knob, so that one person does not occupy many machines, and in the case of an electric fan, It can be used to configure the head to stop shaking when it hits an object or person.

Furthermore, it can be used as a switch for general electronic equipment such as automatic tuning switching for radios and televisions, and since it is a capacitance type, it can also be used as an electronic switch for vehicles, since it works even in shielded rooms.

[Brief Description of the Drawings] Fig. 1 is a circuit diagram showing one embodiment of the present invention, Fig. 2 atb
Figures 3 a, b, and c are time charts for explaining Figure 1, respectively. When the parts are in contact, a is the output pulse of the pulse oscillator 1, b is the input signal from the input terminal, and C is the output pulse of the pulse oscillator 1.
indicate the input signals of the input terminal CP, respectively. 1... Pulse oscillator, 2, 3... Transmission line, 42...
・Contact pole, 43... Resistance between top and ground, 44... Capacitance between top and ground, 5... D flip-flop

Claims (1)

[Claims] 1. A pulse oscillator, each consisting of a resistor and a capacitor, having two transmission paths for transmitting the pulse output, and a contact electrode connected to one of the transmission paths, and a body part coming into contact with the contact electrode. The time constants of the resistors and capacitors of each transmission path are set so that the phase of the pulse transmitted through the two transmission paths is inverted depending on whether or not there is a connection between the ground capacitance and the pulse transmitted through the two transmission paths. A touch switch device comprising a flip-flop in which a pulse is applied to each of two input terminals.