Check if the light touch membrane switch is in poor contact
The allowable large pressing force is uniformly applied to the action direction of the tact switch, and the stroke is measured with the vernier caliper, and the measurement error is not more than 15%. The stroke of the tact switch should be within the specifications of the component specification. After the soldering site is immersed in the flux, it is immersed in the molten solder bath of 240~245°C Sn96.5Ag3Cu0.5 (RoHS material) and 235±5°C Sn63pb37 (non-RoHS material) in the axial direction for 2~3s.
The body is 1.5mm away from the molten solder, and then inquired with a magnifying glass of 3-10 times. Some of the immersed should be tinned and lubricated, and only a small amount of loose defects such as pinholes are not moisturized or weakly moistened, and these defects do not appear in the The same orientation. The extra voltage and extra current that meet the rules of the tact switch specification can be checked by the indicator light to check the continuity of the circuit. Light touch membrane switch supply
The on/off of the switch should be accurate and clear, the operation cycle switch should be smooth, no stuck, and the circuit changed normally. The contact of the movable arm of the adjustable resistance tact switch with the resistor is excellent. Use the ohmmeter of the multimeter to measure both ends of "1", "2" (or "2", "3"), and turn the shaft of the adjustable resistor in the counterclockwise direction to the position of "close". The resistance value is higher. Small is better. Then turn the shank gradually clockwise, the resistance value should be gradually increased, and the pointer in the meter should move smoothly. When the shank is rotated to the pole position "3", the resistance should be close to the nominal value of the adjustable resistor. For example, the pointer of the multimeter has a jumping phenomenon in the process of rolling the shaft of the adjustable resistor, indicating that the movable contact has the disadvantage of poor contact.
Due to its small size, multi-gear position, and good driving force, it has been widely used in many fields such as household appliances. With the continuous improvement of people's living standards, the upgrading of these household appliances is getting faster and faster, and the number of them needs to be larger and larger. This is also the biggest potential direction for us to be optimistic about its development prospects.
