A trimpot or trimmer potentiometer is a small potentiometer which is used for adjustment, tuning and calibration in circuits. When they are used as a variable resistance (wired as a rheostat) they are called preset resistors. Trimpots or presets are normally mounted on printed circuit boards and adjusted by using a screwdriver. The material they use as a resistive track is varying, but the most common is either carbon composition or cermet. Trimpots are designed for occasional adjustment and can often achieve a high resolution when using multi-turn setting screws. When trimmer potentiometers are used as a replacement for normal potentiometers, care should be taken as their designed lifespan is often only 200 cycles.
These small sized switches are placed on PCBs and are used to close an electrical circuit when the button is pressed by a person. When the button is pressed, the switches turn ON and when the button is released, the switches turn OFF. ... Most uses of Tactile Switches are to input an ON/OFF signal to devices.