Capacitive Membrane Switch

Working principle:

The basic principle of capacitive touch sensing buttons is shown in the figure. When the human body contacts the electrode, as the human body is equivalent to a grounded capacitor, a capacitance CF is formed between the sensing electrode and a large area, and the sensing capacitance usually ranges from a few pF to several tens of pF. By utilizing this fundamental principle and building relevant circuits externally, it is possible to detect whether there is human contact with electrodes based on changes in capacitance. 

Application scope

Capacitive touch sensitive buttons have advantages such as being resistant to wear and tear, unaffected by temperature and humidity, waterproof protection, and low cost. Widely used in mobile phones, VCDs, DVDs, induction cookers, range hoods, water heaters, washing machines, microwaves, coffee machines, refrigerators, MP3 players, MP4 players, DPF digital photo frames, and CAR DVDs.

The optional range according to pressure is 125-450 grams.

Electrical performance:

Maximum resistance level: 35V (DC), 100MA, 1W

Loop resistance: varies depending on the length of the output line or designed according to customer requirements

Insulation resistance: ≥ 100 ohms, 100V (DC)

Dielectric withstand voltage: 250V RMS (50-60Hz) for 1 minute

Service life: Over 1 million times

Mechanical characteristics:

Key operation force: 15g~400g

Switching stroke: 0.1-0.5mm

Environmental characteristics:

Working temperature: -30 ℃~+70 ℃

Storage temperature: -40 ℃~+80 ℃

Environmental humidity: 40 ℃, 95%, 240H

Applicable industries:

Instrumentation: measuring instruments, measuring instruments, medical instruments, navigation instruments, industrial instruments

Mechanical and electrical products: CNC machine tools, industrial machinery, industrial appliances

Household appliances: air conditioners, washing machines, induction cookers, microwave ovens, rice cookers, coffee machines, soybean milk machines, remote controls

Office systems: telephones, fax machines, copiers, printers, computer keyboards

Learning products: children's learning machines, reading machines, electronic pianos