METHOD AND CIRCUIT FOR AUTOMATIC CALIBRATION OF THE POWER OF ELECTROMAGNETIC OVEN
First Claim
1. A method for automatic calibration of the power of electromagnetic oven comprising:
- 1) selecting two current test values i1 and i2 within a range of working current of the electromagnetic oven, making a main loop operate in turn in the case of the current test values i1, i2 and zero, detecting voltage values y(i
1){grave over ( )} y(i
2){grave over ( )} y(i
0) of current signals under the three operation states by a current detection and collection circuit;
calculating, by a CPU, a coefficient k and an intercept b according to a formula y(i)=k×
i+b (k≠
0) using the three sets of data, and storing the coefficient k and the intercept b in a memory;
2) during operation of the electromagnetic oven, calculating, by the CPU, a current current signal i using a voltage value y(i) of the current current signal detected by the current detection and collection circuit and the coefficient k and intercept b in the memory, according to a formula i=1/k×
y(i)−
b/k, and in turn calculating a current power value using the current current signal and a current voltage signal detected by a voltage detection and collection circuit.
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Accused Products
Abstract
A method for automatic calibration of the power of electromagnetic oven includes the following steps: 1) selecting two current test values within a range of working current of the electromagnetic oven, making it operate in the case of the current test values and zero, detecting voltage values of current signals under the three operation states; calculating, by a CPU, a coefficient k and an intercept b according to a formula y(i)=k×i+b using the three sets of data, and storing them; 2) during operation, calculating, by the CPU, a current current signal i using a voltage value y(i) of the current current signal detected by the current detection and collection circuit and the coefficient k and intercept b, according to a formula i=1/k×y(i)−b/k, and in turn calculating a current power using the current current signal and a current voltage signal. A calibration program is built in the chip for setting a parameter and automatically colleting and calculating the calibration parameter; during operation, the current or power may be automatically calibrated, which provides an accurate basis for adjusting the power of electromagnetic oven. The mode in which a conventional potentiometer is adopted for calibration may be replaced by the present invention, which results in reduction of cost and improvement of the reliability.
6 Citations
10 Claims
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1. A method for automatic calibration of the power of electromagnetic oven comprising:
-
1) selecting two current test values i1 and i2 within a range of working current of the electromagnetic oven, making a main loop operate in turn in the case of the current test values i1, i2 and zero, detecting voltage values y(i
1){grave over ( )} y(i
2){grave over ( )} y(i
0) of current signals under the three operation states by a current detection and collection circuit;
calculating, by a CPU, a coefficient k and an intercept b according to a formula y(i)=k×
i+b (k≠
0) using the three sets of data, and storing the coefficient k and the intercept b in a memory;2) during operation of the electromagnetic oven, calculating, by the CPU, a current current signal i using a voltage value y(i) of the current current signal detected by the current detection and collection circuit and the coefficient k and intercept b in the memory, according to a formula i=1/k×
y(i)−
b/k, and in turn calculating a current power value using the current current signal and a current voltage signal detected by a voltage detection and collection circuit. - View Dependent Claims (2, 3)
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4. A circuit for automatic calibration of the power of electromagnetic oven comprising:
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a current detection and collection circuit comprising a current sampling circuit, an amplifier and an A/D converter, the amplifier being connected between the current sampling circuit and an input terminal of the A/D converter; a voltage detection and collection circuit comprising a voltage sampling circuit and the A/D converter, an output of the voltage sampling circuit being connected to another input terminal of the A/D converter; a memory for storing a control program, an operation program and a current or power calibration parameter; and a CPU of which an input terminal is connected to an output terminal of the A/D converter, the memory being connected to the CPU;
wherein the CPU calculates the current or power calibration parameter using a predetermined current test value and a detected voltage value of a current signal, stores it in the memory and in turn performs automatic calibration on current current and current power using the calibration parameter. - View Dependent Claims (5, 6, 7, 8, 9, 10)
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Specification