SU987599A1 - Temperature regulator of sectionalized electric heater - Google Patents

Description

(54) TEMPERATURE REGULATOR

ELECTRIC HEATER

one

The invention relates to temperature regulators of electrothermal devices with resistive heaters.

It is known a device for regulating; neither the temperature of the electric heater containing the temperature sensor & parallel to the thyristors C11 Odnoko, this device does not provide high accuracy of maintaining, j temperature and output of the device to the final temperature in a given mode, especially for partitioned heater

The closest to the proposed 20 is the temperature controller of the partitioned electric heater, which contains in the power circuit of each section an actuating unit, mainly

in the form of a triac, the control input of which is connected to the output of the generator, pulses connected to the output of the comparator of this section, to the first input of which the temperature controller is connected, and one temperature sensor connected to the second inputs of the comparator all sections t 2 1.

The disadvantages of this regulator are large temperature differences when putting the unit to the operating mode, overheating of the heated medium, especially in the area where the heaters are located, uneven load of the power source.

The circuit of the invention is to increase the accuracy of temperature control.

Claims (2)

To achieve this goal, in the temperature controller of the partitioned electric heater, the specified connection of the first section generator with the comparator of this section is direct, and the input of the generators of the other sections 9 is connected to the RS trigger outputs, the R inputs of which are connected to the outputs of the comparators of these sections through the pulse shapers, S-Inputs are connected to the outputs of the coincidence circuits associated with the Outputs of the indicated comparators by the first inputs and with the output of the comparator of the first section by the second inputs. The drawing shows a regulator circuit. The comparator regulator is designed to control the heating of, for example, three sections 1, 2 and 3 of the electric heater. It contains sensor 4, temperature amplifier 5, comparators 6-8 in the control channels of each section, setting devices 9-11 of temperature, two 1213 matches, drivers 14, 15 pulses, two RS flip-flops 16 and 17, generators 18-20 pulses and actuators in the form of triacs 21 23. The device works as follows. When the circuit is turned on, the generators 18, 19, and 2 O of all channels produce pulses arriving at the control electrodes of the triacs 21–23. A current flows through electric heaters 1–3, and the temperature rises. The voltage from the output of the temperature sensor 4 is fed to the input of the amplifier 5, and then to the inputs of the Comparators 6 8 of each channel. The comparator b of the first channel is set to temperature -fc. ,, comparator 7 of the second channel - to temperature 2, the comparator 8 of the third channel - to temperature t-., And i., T2 bWhen the temperature of the chamber where temperature sensor 4 is installed reaches The tn and t comparators of the respective channels are tilted, but the triggers of channels 6-8 remain in the initial state, and the generators 1820 continue to operate. When the temperature reaches the value -L, the comparator 6 is triggered, signal 1 is received at both inputs of the coincidence circuits 12 and 13, owing to which a negative pulse arrives at the S trigger input, the overturning triggers. The generators 18-20 lock up, and the triac 21-23 closes. and the heating stops. The temperature in the chamber drops. Decreasing the temperature to the value of the t-t comparator 6 comes to its initial state, the generator 18 is unlocked 9 4 and the triacs 21 of the first section are opened. If the temperature drops to t 2, the comparator 7 returns to its original state, the pulse shaper 14 returns the trigger to its original state, and the triacs 22 of section 2 open. If the temperature drops to t -tj, the comparator 8 returns to its original state and opens triacs 23 sections 3 electric heaters. In the following, the process is repeated. The device can be used in technical. ecological processes with a precisely defined heating and cooling program, for example, during heat treatment of reinforced concrete structures, preparation of bitumen, in the production of asphalt concrete, etc., excluding abrupt changes in power loads by connecting the optimal power of electric heaters and) Avoiding overheating of products. The invention Regulator of the temperature of a sectioned electric heater, containing an actuating unit in the power circuit of each section, mainly in the form of a triac, the control input of which is connected to the output of the pulse generator connected to the output of the comparator of this section, to the first input of which the temperature setter is connected, and one temperature sensor common for the regulator, connected through an amplifier with the second inputs of the comparators of all sections, characterized in that, in order to increase the accuracy of the regulation The temperature indicated by the first section of the generator with the comparator of this network is directly, and the inputs of the remaining sections are connected to the outputs of the R5 triggers, the R inputs of which are connected to the outputs of the comparators of these sections via pulse shapers, the S inputs are connected to the outputs of the matching circuits associated with the outputs of the indicated collectors by the first inputs and with the output of the comparator of the first section - by the second inputs. Sources of information taken into account in the examination 1. Patent Germany No. 2734549, cl. H 05 B 1/02, 1978.. 2. Electrical equipment and automation electrothermal installations. Handbook of M., Energie, 1978, 1C. 94-121.