SU1425824A1 - Touchless switch - Google Patents

Description

(21) 4105751 / 24-21

(22) 05/14/86

(46) 09.23.88. № 35 (72) A.V. Trushin

(53) 621.374 (088.8)

(56) USSR author's certificate

 1010726, cl. H 03 K 17/945, 1983.

USSR Author's Certificate 834918, cl. H 03 K 17/945, 1981.

(54) TOUCH SWITCH

(57) The invention relates to a pulse technique and can be used in control panels. The purpose of the invention is to increase the reliability of the operation of the device due to the improvement of isolation.

touch pads from the generator output and information reading when it touches the second polling pulse. The switch contains generator I, counter 2, sensor cells 3, digital switch 4, shift register 5, elements 6.8 and 9, memory register 7. Each sensor cell 3 consists of a touch pad 10, a voltage divider I1, a differential amplifier 12, transistors 13-17, resistors 18-22. The divider voltage is connected to the resistors 23 and 24. The number of channels in each case is determined by the requirements of the corresponding keyboard. I 3.p.f-ly, I il.

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11425824

The invention relates to a pulse technique and can be used in control panels.

The purpose of the invention is to increase the reliability of the operation of the device by improving the separation of the touch pads from the generator output and reading the information when it touches the second interrogation pulse. 0

The drawing shows an electrical functional circuit diagram of the device.

The device contains a generator 1, the output of which is connected to the input of counter 2, sensory cells 3, digital switch 4, shift register 5, first element 6, memory register 7, second element 8 and third element 9, and each sensor cell 3 consists of a touch pad 10, a division of 20 voltage bodies 11, a differential amplifier 12, the first, the second. the third of its fourth and fifth transistors 13-17 and the first, second, third, fourth and fifth resistor 18-22, the output of the first discharge of counter 2 is connected to the second input of the third element 9, the non-inverting input of the second element Both 8 and the inputs of the sensing cells of the DA 3, the output of the second discharge of the counter 2 is connected to the third input of the third element AND 9, the output of which is connected to the recording resolution input of the shift register 5 and the first input of the first element 6, the outputs of the sensor cells 3 are connected to the corresponding inputs digital comm At 4, the remaining high bits of counter 2 are connected to the corresponding bits of the digital, switch 4 and memory register 7, in each sensor cell 3, the touch pad 10 through the fifth resistor 22 is connected to the emitte

The pulse sequence of generator 1 arrives at the gaps of counter 2 and at the inputs of the second and three of its elements 8 and 9, respectively, on which the pulse of the sequence is formed: on the second element of the 8, synchronization pulses on the third element 9 installation impulse. The signal of the first digit of counter 2 is received simultaneously by all the sensory cells 3. This signal is a meander with logical levels. It enters the ba of the first transistor 13 and through the divider II to the base of the second. Transistor 14. In the absence of contact between the sensor platform 10 at the output of the differential amplifier 12, the voltage is always anti-phase input for the following reasons. The input signal crashes the first and second transistor 13 and 14, respectively. The base then the second transistor 14, having flowed across the parallel connected resistors 23 and 24 of the splitter 11 against the common bus, creates a base voltage for the transistor 14 and therefore the non-inverting input of the differential amplifier 12 for ground potential. this output signal will correspond to the Log. The input signal to Log.1, arriving at the base of the second transistor 14 through the 11d divider, decreases in magnitude, becomes smaller than the signal based on the first transistor 13, i.e. the potential of the inverting input of the differential amplifier 12 is the potential of its non-inverting input. Therefore, the output signal of the differential amplifier 12 changes

rum of the third transistor 15, a collection of j D ° level Log. O. When touched

touch pad 10 An operator body capacitance is connected to the emitter of the third transistor 15 When the sensor cells 3 at the input of the Log.On input act, transistors 13 and 14 are open and the capacitance is applied to the voltage of transistors 15 and 13.

the torus of which is connected to the emitter of the first transistor 13 and the inverting input of the differential amplifier 12, the non-inverting input of which is connected to the emitter of the second transistor 14, the base of which is connected via the voltage divider 11 to the input of the sensor cell 3. In addition, the voltage divider 11 from per50

touch pad 10 An operator body capacitance is connected to the emitter of the third transistor 15. When the sensor cells 3 input the Log.On input signal, the transistor 13 and 14 are open and the input capacitance is charged to the voltage of transistors 15 and 13.

After passing positive

the first resistor 23 and the second resistor, the signal front transistors 13 and 14

pa 24 connected between the common bus and the output of the voltage divider 11. The device operates as follows.

decay and increase in the fallout of them. The capacity of the operator's body begins to charge along the circuit: power supply, resistor

5 0 5 O 0

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The pulse sequence of the generator 1 is fed to an H-bit counter 2 and to the inputs of the second and third parts of its elements 8 and 9, respectively, on which the sequence pulses are formed: on the second element 8, synchronization pulses, and on the third element 9 installation pulses . The signal of the first bit of counter 2 arrives simultaneously on all sensory cells 3. This signal is a meander with logic levels. It goes to the base of the first transistor 13 and through the divider II to the base of the second transistor 14. In the absence of contact between the touch pad 10 at the output of the differential amplifier 12, the voltage is always anti-phase to the input for the following reasons. The input signal from the first and second transistors 13 and 14, respectively. The base current of the second transistor 14, having flowed across the parallel-connected resistors 23 and 24 of the voltage divider 11 to the common bus, creates a voltage drop across them, relative to the ground potential of the base of the second transistor 14, and therefore the non-inverting input of the differential amplifier 12. At the same time the output signal will correspond to the Log. The input signal Log.1, arriving at the base of the second transistor 14 through the voltage divider 11, decreases in magnitude, becomes smaller than the signal at the base of the first transistor 13, i.e. the potential of the inverting input of the differential amplifier 12 potential of its non-inverting input. Therefore, the output of differential amplifier 12 changes

 D ° Level Log.O. When touched

sensor pad 10 An operator body capacitance is connected to the emitter of the third transistor 15. During the action at the input of the sensor cell 3, the signals of Log.O. transistors 13 and 14 are open, and the input capacitance is charged to the voltage of transistors 15 and 13.

After passing the positive

build up, and the voltage drop across them increases. The capacity of the operator’s body begins to charge in a circuit: power supply, resistor

ry 19 and 22, The voltage drop across the resistor 19 against the charging current closes the transistor 15. This reduces the voltage and the input current at the inverting input of the differential amplifier 12, amplifying the signal of its non-inverting input, and the output signal has a high potential, common-mode to the input signal Q of the sensor cell 3. As the capacitance charges, its charge current decreases; the transistor 15 opens, its collector current increases and, accordingly, the voltage on the inverting input of the differential amplifier 12. When the voltage is exceeded The voltage at the non-inverting input of the differential amplifier 12 at this input changes the phase of the output signal to 20 seconds, decreasing to the value of Log.O. Thus, a hitch occurs. the negative edge of the pulse of the high signal for the time determined by the value of the input capacitance. 25

The discharge of the input capacitance occurs after passing the negative front of the output signal of the first discharge of counter 2 through resistor 22 and transistors 15 and 13. Similarly, all the sensor cells 3 work. The signals from them are fed to the corresponding inputs of the digital switch 4. The signal of the portion of the output voltage of the differential amplifier 12 is produced by a digital switch 4 on the input. With synchronization pulses. The output signal of the switch 4 is generated when the output pulse coincides. a potential amplifier 12 and a synchronization pulse. The duration of the synchronization pulse is equal to half the period of the oscillator frequency 1. When the sensor cell 3 is touched

the coincidence of the closed part of the output pulse of the differential amplifier 12 and the synchronization pulse occurs. As a result, a short control pulse appears at the output of switch 4. Moreover, during the polling period of each sensor cell 3, the output of the switch 4 passes two control pulse names when the corresponding sensor cell 3 is turned on and not a single pulse in the absence of touch of the touch pad 10.

Management of switch 4 on inputs A,, ..., A is performed by the eldest with

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Q 20

five

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five

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The 3rd by the tth digit of counter 2. Depending on the counter code, a corresponding touch sensor cell 3 is connected to the output of switch 4. At the end of the polling period of each sensor cell 3, the pulse is set to the shift register 5 at the write resolution input C Log.1 is written into its first bit. Two control pulses, arriving at the shift control input C of the shift register 5, shift and write Log.1 to the third bit of this register. With the next set-up pulse arriving at the first input of the first element 6, a write pulse appears at its output, the counter code 2 corresponding to the activated sensor cell 3 that writes into memory register 7. This code is output to the device. By a negative edge of the write resolution pulse, the shift register 5 is again reset, i.e. Log.1 is written to its first bit, and the remaining three are Log.O and so on. If there are no shift control pulses or if there are single failures, the output code in memory register 7 remains unchanged. If there are more than two shift control pulses, memory register 7 is zeroed by the signal from the fourth output of shift register 5.

The number of channels is determined by the requirements for a particular keyboard.

Claims (2)

1.Touch switch containing generator, sensor cells, digital switch, counter, first AND element and memory register, generator output is connected to the counter input, the senior outputs of which, starting with the third, are connected to the corresponding address inputs of the digital switch and memory register , the output of the first element I is connected to the input of the recording resolution of the register of memory, the outputs of the sensor cells are connected to the corresponding information inputs of the digital switch, each sensor cell contains a sensor area This and the inputs of all sensor cells are combined, distinguishing-. so that in order to increase 51 reliability of operation due to improved separation of the touch pads from the generator output and reading the information when the second interrogation pulse is touched, the second and third elements AND, {the shift register, the number of counter bits are increased by two bits, are inserted into it A differential amplifier, a divider (voltage, five pnp type transistors, and five resistors are inserted into the sensor cell, and the generator output is connected to the inverting input of the second element AND to the first INPUT of the third element AND, the output of the first razr yes the counter is connected | from the non-inverting input of the second element I, to the second input of the third {Element I and the input of the first sensory stream, the output of the second digit of the counter | is connected to the third input of the third element I, and entrance is allowed No record of the shift register, the output of the second element I is connected to the synchronization run of the digital switch, the output of which is connected to the shift control shift input INPUT of the shift register, the first information input of the shift register is connected to the logic 1 bus, and the rest of its information inputs are connected to the logical O pin, the output of the third digit of the shift register is connected to the second input of the first element AND, you 15 20 25 thirty 35 the fourth bit of the shift register goes to the memory register reset input, and in each sensor cell its input is connected to the base of the first transistor and through the voltage divider to the base of the second transistor, whose collectors are connected to the common bus, the emitter of the first transistor is connected to the collector The third transistor and the inverted input of the differential amplifier, the emitter of the second transistor is connected to the collector of the fourth transistor and the non-inverting input of the differential amplifier, the output of which is connected to the output of sen the weed cells, the bases of the third and fourth transistors are connected and ° connected to the base and collector of the fifth transistor and through the first resistor to the common bus, the emitters of the third j: fourth and fifth transistors are connected via the second, third and fourth resistors respectively to the positive power supply terminal, A sensor pad via the fifth resistor is connected to the emitter of the third transistor. 2. The switch according to claim 1, wherein the voltage divider consists of the first and second resistors, the input of the voltage divider through the first resistor connected to the output of the voltage divider, and the output of the voltage divider is che. cut the second resistor connected to the common bus.