RU1783495C - Multi-channel temperature controller - Google Patents

Abstract

The invention can be used in automatic temperature control and is intended for thermoregulating an object according to a given program simultaneously in several heating zones. The purpose of the invention is to improve performance by introducing a PWM pulse regeneration unit 9, consisting of a group of identical regeneration elements 10. having input I, II, III and output IV terminals connected respectively to the output of the second group of keys 8, to the clock output of the counter 14 , to the output of the GTI 12 and the actuator 11 With the help of the regeneration unit 9, all channels are controlled in parallel, including the time intervals when the thermal converter is disconnected from the control circuit. 3 ill.

Description

Fie. 1

The invention relates to automatic temperature control and can be used to thermally control an object according to a given program simultaneously in several heating zones.

A device is known that contains blocks of primary and secondary sensors, a block of circulating devices, a time-sharing unit for measuring and regulating processes, a control block, correction blocks, drives of analog quantities, actuators, a block of digital manual adjusters, a digital-to-tax converter, an input register , resistive divider, voltage switch, reference voltage source, switch, summing and ratio unit, OR element, key, first and second inverters, first and second sums tori 1.

A disadvantage of the Device is its low speed.

Closest to the invention in technical essence is a device comprising a controller, a temperature setting unit, a digital-to-analog converter, a comparison circuit, a proportional block, a threshold element, a sawtooth voltage generator, an amplifier, key groups, a thermal converter, discrete filling blocks, actuators, variable coefficient setting unit, clock generator, frequency divider, switches, ring counter, decoder 2.

A disadvantage of the device is its low speed.

The aim of the invention is to increase the speed, which is achieved by introducing into the multichannel controller a PWM pulse regeneration unit, consisting of a group of identical regeneration elements with a total number equal to the number of adjustable channels, and each of their outputs is connected to the corresponding actuator, the first inputs are connected with the corresponding outputs of the second group of keys, the second inputs are combined and connected to the output of the least significant bit of the counter connected to the input of the sawtooth generator p voltage, the other counter bitwise outputs connected to inputs of the decoder, the outputs of which are connected with the address inputs of the set point temperature, the third inputs of all elements of the regeneration unit are also combined and connected to the output of the clock, the frequency divider output coupled to an input of the counter

In FIG. 1 is a functional diagram of a multi-channel temperature controller; in FIG. 2 is an embodiment of a regeneration unit; Fig 3 is a cyclogram

device operation.

The device comprises thermal converters 1, a first group of keys 2, a digital temperature controller 3, a digital-to-analog converter 4, a comparison circuit 5, a sawtooth voltage generator 6, a threshold element 7, a second group of keys 8, a pulse-width modulated pulse generator 9 consisting of elements 10 , actuators 11, clock generator 12,

5 frequency divider 13, pulse counter 14, decoder 15. Element 10 contains AND 16, 17, HE 18, 19 elements, reversible counters 20, 21, IK-trigger 22, RS-trigger 23, differentiating element 24, OR element 25, input I, II III and output IV terminals.

The device operates as follows. In the initial state, the device is de-energized. At the time of submission to the device

5 of the supply voltage, the circuit elements are zeroed. The decoder 15 is in the initial position at which the output signal is present at its first output. This signal is coming

0 simultaneously to the control inputs of the first and second groups of keys 2, 8 and the first address input of the temperature setter 3. In this case, the thermal converter 1 of the first

5 of the channel, the binary code of the set control temperature of the first channel is read to the input of the digital-to-analogue converter 4, the output of the threshold element 7 through the second group of keys 8 is connected to input I of the first element 10. After the zeroing pulse ends, the time interval T0 starts to form on the frequency divider 13. At the same time, the sawtooth generator 6 starts up.

5 The inputs of the three elements 10 receive pulses from the output of the generator 12. The digital code is converted in the DAC 4 to the analog equivalent voltage supplied to the second input of the comparison circuit 5

0 As a result of comparing the voltage values at the inputs of the comparison circuit 5, a signal is generated at its output equal to the difference of these voltages, which is fed to the input of the threshold element 7.

5 During the formation of the interval T0 (duration of one cycle) at the output of the sawtooth voltage generator 6, the voltage changes linearly

At the moment of equal voltage at the inputs of the threshold element 7 is measured

the voltage level at its output, which is maintained until the end of the T0 cycle, i.e. based on the interval T0, a PWM pulse is generated. Its duration is proportional to the mismatch between the set and actual temperatures. The PWM pulse through a group of keys 8 is fed to the input I of the first element 10 and then goes through its output IV to the input of the actuating element 11. At the same time, the pulse width of the PWM pulse is stored in the first element 10 of the regeneration unit 9.

After the completion of the first clock cycle T0, the state of the counter 14 changes, as a result of which the control command appears at the next output of the decoder 15. Instead of the first thermal converter 1, the second is connected to the input of the comparison circuit 5, the temperature data of the second channel, the output of the threshold element 7 is disconnected from the input of the first element 10 and switches to the input of the second element 10.

At the same time, a restart 4 of the sawtooth voltage generator 6 is restarted. 6. The PWM pulse in the second channel is generated similarly to the first channel.

The generated PWM pulse is fed to the input of the second actuating element 11. The value of its duration is stored in the second element 10.

During the same cycle, the first element 10 generates a PWM pulse, the duration of which is equal to the duration of the pulse received at its input in the first cycle. Through output IV, the PWM pulse is fed to the input of the first actuator 11 and controls it, i.e., both channels are regulated in parallel

Then the next channel is connected, and so on, until the completion of the complete interrogation cycle of all thermal converters 1.

During the complete interrogation cycle of thermal converters 1, all but 10 elements are disconnected from threshold element 7 and generate PWM pulses at each T0 cycle when the corresponding channel is connected

In the process of generating a clock pulse To, triggers 22, 23 are triggered. By voltage log 1 from the inverse output of trigger 22, counter 20 is set to the addition mode and voltage is set to log. О from its direct output, the counter 21 is set to the subtraction mode. At the same time as the clock pulse T0, a positive PWM pulse arrives at the input I At the output of the element NOT 18 during the action of the pulse

a logical O is established which blocks the passage of signals through the And 17 element at the first input When the trigger 23 is triggered, the voltage is log 1

5 is fed to the output of the circuit (terminal IV) and the input of the And 16 element, thereby allowing the passage of signals with a high filling frequency from the generator 12 through input 3 and the And 16 element to the counting input of the counter 20

0 At the counting input of the counter 21, filling pulses are not received at this time. Counter

20 is filled with pulses until the end of the operation of the PWM pulse at input I. At the time of its end, the differential pulse of 5, corresponding to the trailing edge of the PWM pulse, is inverted by the element HE 19 and through the element OR 25 it is fed to the input of resetting the trigger 23.

0 Trigger 23 is reset. The pulses to the input of the counter 20 are stopped, the counter 21 remains in its initial zero state. An impulse equal to

5 pulse width PWM.

The number of pulses N received at the input of the counter 20 over time (and the action of the PWM pulse is

N 0N tnr

where tnr is the oscillation period of the generator 12,

When the next clock pulse T0 arrives at input II, the PWM pulse does not arrive at input I.

5 As a result, the input of AND element 17 is in a log state. 1 and allows the passage of signals from input 111 to the counter

21 Trigger 23 Trigger Again

22 also switches, since it works- 0 in counting mode (division bd 2)

In this case, the counter 20 starts operating in the summing mode. The signals from input III arrive immediately at both counters 20, 21. At the time of decreasing the content of counter 20 to zero 5 l, those. subtracting from it the number of pulses equal to N, a voltage pulse appears at the output of the counter 20, which switches the trigger through the OR 25 element

23 в initial zero state Receipt of pulses to counters 20, 21 from input III

ceases. Obviously, after stopping the count, the counter 21 is filled with a number of pulses equal to N.

At the output IV, a pulse of 5 will be generated, the duration of which is equal to

tBblX T.I. 1PG,

those. in the absence of a PWM pulse at input I, an output equal to its duration will be generated at the output of the IV circuit.

In the next step T0, the contents of the counter 21 are transferred to the counter 20, etc.

Thus, at each T0 cycle, the circuit regenerates a voltage pulse, the duration of which is equal to the duration of the pulse received earlier at input I when interrogating the thermal converter.

The regeneration process continues until the next pulse arrives at input I after the interrogation of all thermal converters. At its leading edge, the circuit is again reset. Further, the operation of the circuit occurs similarly to that described above.

Thus, the device of the present invention is highly responsive and its advantage is better at increasing the number of channels. It should also be noted that as the pulse repetition rate of the PWM increases, the level of pulsations of the control temperature also decreases.

Claims (2)

1. A multi-channel temperature controller containing a group of thermal converters connected to the information inputs of the first group of keys, a second group of keys, the control inputs of which are connected to the outputs of the decoder, a comparison circuit connected to the input with the output of the first group of keys, a temperature setter and a digital an analog converter, the output of which is connected to another input of the comparison circuit, a sawtooth voltage generator, a threshold element, the first input connected to the output of the generator the sawtooth voltage, the second input to the output of the comparison circuit, and the output to the information input of the second group of keys, a group of actuators, series-connected clock generator and frequency divider, pulse counter, characterized in that, in order to improve performance, It introduced a PWM pulse regeneration unit, consisting of a group of identical regeneration elements with a total number equal to the number of adjustable channels, each of their outputs connected to the corresponding actuator, the first inputs connected to the corresponding outputs of the second group of keys, the second inputs combined and connected to the low-order output of the counter connected to the generator input sawtooth voltage, other outputs counter bottom bit connected to the inputs of decryption  a radiator, the outputs of which are connected to the address my temperature setpoint inputs, third inputs of all elements of the regeneration unit also combined and connected to the output of the clock generator, the output of the frequency divider is connected to the input of the counter. 2. Controller pop, 1, characterized the regeneration element consists of the first and second reversible counters, the first and second AND elements, the OR element, the differentiating element, the first and second elements NOT, the RS trigger, the IK trigger, wherein the first input of the element is the input of the first element NOT, combined with the input of the differentiating element connected sequentially1 but with the second element NOT, the output of the first of the element is NOT connected to one, we enter the first element AND, the other input of which is connected to the output of the second element And and the counting input of the first reversible counter, the counting input of the second reversing the counter is connected to the output of the first AND element, and the outputs of both reverse counters through the OR element are connected to the zeroing input of the RS flip-flop, the output of which, which is the output of the element, is connected by one input of the second AND element, the other input of which is the third input of the element, the inputs of both the triggers are combined and are the second input of the element, the outputs of the IK trigger are connected to counter reverse control inputs, and the output of the second element is NOT connected to the third input of the OR element.  . 0. HI OTO eighteen IT sixteen far 2 -T, Ts TI R l 4.4 1hav. 2xa &. i "J 20 r 25 J Ju IELILIL3 1 a