Waterproof tactile switch is a functional electronic switch that can be turned on by gently pressing the switch button. The internal structure of the switch is achieved by the force and movement of metal spring plates; Due to its low contact resistance, clear tactile sensation when pressed, and complete height specifications, waterproof tactile switches have diverse applications and packaging specifications, especially in household appliances where they are widely used. How to detect waterproof tactile switches is important for the principle of waterproof tactile switches. What is the working principle of waterproof tactile switch?

The working principle of waterproof tactile switch: For example, 220V AC power passes through the light bulb H and rectifier full bridge, and becomes a DC pulsating voltage, which is used as a forward bias and applied to the thyristor VS and R branches.

1. When the brightness is below a certain level at night, the photodiode D exhibits a high resistance state of ≥ 100K Ω, causing the transistor V to conduct in the forward direction and the emitter to have a voltage of about 0.8V, triggering the thyristor VS to conduct and causing the light bulb H to emit light.

2. When the daytime brightness exceeds a certain level, the photodiode D exhibits a bottom resistance state of ≤ 1K Ω, causing the transistor V to cut off and its emitter to have no current output. The unidirectional thyristor VS is blocked due to the absence of trigger current. At this time, the current flowing through bulb H is ≤ 2.2mA, and bulb H cannot emit light. The resistor R1 and the voltage regulator diode DW ensure that the bias voltage of the transistor does not exceed 6.8V, which can provide protection for the transistor. RP is a brightness selection component that switches between morning and evening.

The process of waterproof tactile switch includes stamping, injection molding, cleaning, assembly, molding, and inspection. Its color is relatively simple. Due to the high requirements of the production environment for waterproof tactile switches, the use of workshops with higher dust prevention levels ensures better product quality. In addition, the cost and price of waterproof tactile switches are relatively low, and generally do not experience significant price adjustments due to fluctuations in market raw materials.

There is a type of switch that is very similar to a waterproof tactile switch, called a membrane switch. The difference between the membrane switch and the waterproof tactile switch is that the membrane switch is a button with its own circuit. Usually, the top layer is a panel with text or patterns made of materials such as PET or PC, the bottom layer is a conductive circuit, the middle layer is a double-sided adhesive made of PET material that simulates the form of the switch and serves as an isolation function, and the bottom layer is usually the contacts and connecting lines on the PET material. The membrane switch is convenient and flexible to use, and can be customized in different colors, sizes, and appearances according to different needs.