The first pin voltage of the induction cooker is 5.14V, the second pin is 0.26V, the third pin is 18.45V, the fourth pin is 5.12V, the fifth pin is 4.7V, the sixth pin is 3.86V, the seventh pin is 4.02V, the eighth pin is 1.37V, the ninth pin is 4.76V, the 10th pin is 5.64V, the 11th pin is 1.88V, and the 12th pin is 0V.
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The output of the LM339 is equivalent to a transistor without collector resistance. In use, the output must be connected to a positive resistor (called a pull-up resistor, 3-15K). Choosing pull-up resistors with different values will affect the high potential value at the output. Because when the output transistor is off, its collector voltage basically depends on the value of the pull-up resistance and the load. In addition, the outputs of the comparator are allowed to be joined together.
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When the grid voltage is normal, 1\/4LM339 U4
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When the grid voltage is greater than 242V, U4> 2.8V, the comparator flipped, the output is 0V, BG1 cutoff, the voltage of U5 is completely determined by the partial voltage value of R1 and R2, which is 2.7V, prompting U4 to be greater than U5, which makes the state after flipping extremely stable, avoiding the instability caused by small fluctuations in the power grid voltage near the overvoltage point.
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If it works
G pin is generally between 0-15V or -5V-15V; -5V is for complete shutdown or not; Here generally refers to the voltage between GS;
D is probably the same level as S when it is on, and may be high when it is not on; The waveform of D is very close to that of G; After all, G is driving D;
S is generally grounded; The simple connection is ground;
The method of determining GSD is very simple, look at the drive circuit can see, generally D connected to the coil or power supply; S junction; G to a signal driven output;