With the rapid development of China's information and electronics industry, the fields touched by small home appliance control boards have covered all electronic products; As one of the core components of various household appliances, most of its specific programming functions rely on small appliance control boards, so its disturbance problem has become the most headache for people. So how to solve its load disturbance problem?

The load disturbance in the control board of small household appliances includes linear load (such as water heater) and nonlinear load (soybean milk machine, meat grinder, etc.). Because nonlinear loads are extremely wideband disturbance sources. Therefore, regarding the above disturbances, especially those caused by nonlinear loads, there are two solutions:

Top method: Start with non-linear loads (such as motors) themselves. Due to improper operation, poor touch of the touchpad, and unclean carbon brushes, disturbance conditions several times higher than normal operation can occur. In order to reduce disturbance, it is necessary to ensure that the touch of the touch device is firm, the opening and closing actions are normal, and the pressure on the contact head is maintained. In addition, it is necessary to maintain the cleanliness of the carbon brush and commutator, as well as the quality of the carbon brush itself and the smoothness of the commutator; Also, it is necessary to protect the carbon brush from exerting appropriate pressure on the commutator; Finally, it is necessary to ensure that the machine base is firmly fixed to avoid instability caused by mechanical operation.

The second method: Select the necessary electrical filtering method, and the circuit connection is shown in the following figure. The purpose of this circuit is to provide a low impedance path for the disturbance potential to suppress the disturbance value. In the figure, C1 represents a capacitor with a smaller inductance component, usually ranging from tens to hundreds of nF; C2 uses a through core capacitor, generally ranging from 1 to 4.7nF. The purpose of adding this capacitor is to suppress noise, but the installation direction of the capacitor is different, and the interference suppression effect in the very high frequency range will vary greatly. Therefore, special attention should be paid to the shortest connection between the grounding shell of the capacitor and the motor base or metal shell during installation. When connecting together, the electromagnetic interference in the input and output parts of the capacitor should be minimized as much as possible.

Article source: Small home appliance control board IC http://www.zbchip.com/