Jane Summer Soot, Gansu Zhang Xiaodong. Currently, the control system of range hoods typically employs membrane buttons with integrated circuits or specialized thyristor regulators, which results in complex circuitry and higher costs. To address this issue, the author has developed a simplified touch-control switch using a new type of relay with auxiliary contacts and a switch-type tactile button. This design reduces the cost by approximately 10 yuan compared to similar circuits. The reduced number of components also leads to a lower failure rate, improved anti-interference capability, and low power consumption—measured at only about 0.7 watts. Notably, there is no static power consumption after shutdown, as the power transformer is not involved.
The range hood features a light-touch switch that controls the motor and lighting functions. The circuit includes a relay with auxiliary contacts, a conversion-type tactile switch (model 53383), and other components like the motor, bulb, and fuse. These elements work together to form a cross-controlled interlock switch for oil absorption. The motor can operate at high speed or low speed, depending on the switch position.
For the lighting function, a one-button bistable switch composed of a crystal triode (model 10384) controls the illumination lamp. The power supply circuit consists of a transformer (model 1), rectifier diodes (models 6, 9), and a capacitor (model 02), converting 220V AC to a 12V DC power source for the control circuit.
Under normal conditions, relays K1 and K3 are de-energized, so the motor does not run, and the bulb remains off. When the tactile switch 381 is pressed, relay K1 is energized, closing its common contact K11 and powering the motor to operate at high speed. At the same time, the auxiliary contact closes, creating a new power loop through transistor 2582, keeping the relay engaged even after the switch is released. Pressing 582 cuts off the relay’s power, stopping the motor. Meanwhile, pressing SB2 activates relay K2, allowing the motor to run at a slow speed.
When the light switch (model 384) is pressed, capacitors C1 charge up, triggering the transistor 71 to turn on, activating the relay and lighting the bulb. The auxiliary contact K32 ensures the relay remains active after the switch is released. Pressing 384 again causes the capacitor voltage to drop, turning off the transistor and cutting power to the bulb. This allows the user to toggle the light on and off with each press.
In the circuit, LEDs 003 and their current-limiting resistors are connected in series with the relays, and they are paralleled across the relay terminals to indicate the motor's operating status and the bulb’s on/off state. VD4 and resistor R4 are connected in parallel with the motor’s control circuit, providing a visual indicator of whether the motor is running.
For component selection, the author recommends a domestic small-shell 30-type electromagnetic relay with auxiliary contacts. The 58584 model uses a 123-type conversion-type tactile switch. The 30-type relay offers coil self-protection and signal-level output via its auxiliary contacts, making it more compact and cost-effective than traditional relays. The transformer is rated for 220V AC input, 12V AC output, and 1.5W power, ensuring long-term reliable operation. The transistor used is either 9014 or 3068, with a current rating of 150mA.
The printed circuit board for the control switch does not include the power supply circuit. Its actual size is approximately 130mm². During soldering, the LED 004 and tactile switch 584 should be mounted on the copper foil side of the board to ensure visibility during operation. Once assembled, the board is fixed onto the control panel of the range hood.
This control switch requires no adjustment after assembly and can be directly installed as a replacement part for manufacturers or used to upgrade existing range hoods. It is mounted on the plastic film of the hood’s exterior, and wiring connects it to the controlled devices. This design offers an efficient, cost-effective, and user-friendly solution for modern range hood controls.
Sorghum Leaf Door Curtains
Sidelight Curtains,Patio Door Curtains,Curtains For Closet Doors,Sorghum Leaf Door Curtains
Shandong Guyi Crafts Co.,Ltd , https://www.gyicraft.com