SU794619A1 - Proportional temperature regulator - Google Patents

Description

The output of the transformer / connected to the input of the rectifier 5 and one of the inputs of the switching element 2, the output of which is connected to the input of the actuator 3 and the input of the scaling unit 4, the output of the scaling unit 4 is connected to the first input of the comparison element 7, the second input of which is connected to the output driver voltage reference 6; input driver voltage reference 6 is connected to the output of the rectifier 5.

The imaging unit 8, the modulator 9, the integrator 10 and the threshold element // are connected in series, the output of the threshold element // is connected to the control input of the switching element 2, the input of the imaging unit 8 is connected to the output of the rectifier 5, the output of the comparison element 7 is connected to the second input modular torus 9.

On fng. 2 accept the following notation:

i f (| rm is the voltage at the output of the driver 8;

and is the voltage across the integrator 9; and 1pir is the voltage of the former 6;

whether - the voltage mismatch arriving at the integrator input; t / threshold - signal at the output of the threshold

element / y;

i iiarp is the load voltage; Fy F2 - phase angles of the opening of the switching element.

Proportional temperature controller works as follows.

From the transformer 1, the alternating incidence goes to the switching element 2 and then to the load (executive element 3). At the same time, this voltage goes to the rectifier 5. The rectified voltage through the shaper 6 goes to one of the inputs of the reference element 7.

Filtered DC voltage is supplied to the second input of the element from the scaling unit 4, proportional to the voltage on the actuator 3. To ensure temperature control of the executive element 3, the voltage from the switching element 2 is supplied to the comparison element 7 through the scaling unit 4.

At the output of the element of comparison 7, a constant voltage of the error is generated, proportional to the deviation of the output voltage from the set (reference level).

The error voltage is supplied to the first input of the modulator 9, to the second input of which the trapezoidal voltage is applied, which is obtained by means of the driver 8 from the rectifying voltage.

Trapezoidal pulses appear at the modulator output, the amplitude of which is inversely proportional to the controlled value.

These pulses arrive at the integrator W, whose time constant is (approximately) the device's supply voltage half-period. Increasing the voltage on the integrator to a certain level leads to the triggering of the threshold element //, causes the opening of the switching element 2, which occurs when the supply voltage passes through zero.

The device works as follows.

When changing (decreasing) the output voltage at a load caused by a change in load or voltage, the difference signal goes to the modulator 9, from which output the trapezoidal pulses are transmitted to the integrator 10.

The direction on the integrator 10 varies by law, close to exponential.

Since the integration constant is unchanged and the output voltage of the modulator 9 changes with f / and, U ,,, and the integration time changes with / i to t.

Accordingly, the response time of the threshold element 11 will change, which will cause a change (decrease) in the phase angle of opening of the switching element 2.

In this case, the key will be open for most of the half period and, therefore, the output voltage (average) will increase.

Similarly, the process occurs with an increase in output voltage.

Thus, the proposed controller allows an increase in the accuracy of temperature control by stabilizing the output voltage caused by a change in load or supply voltage.

Claims (2)

1. Author's certificate No. 226E22, cl. G 05 D 23/24, 1967. 2. USSR author's certificate number 491123, cl. G 05 D 23M9, 1974 (prototkp). FIG. 2