1. Working Principle of Thermostat
Made based on the thermal expansion and contraction property of substances.
2. Capacitor: Definition & Classification
Capacitor is a charge-storing/releasing electronic component, made of two positive/negative electrodes with insulating dielectric in between (its type is determined by electrode and dielectric material).
Core functions:
- Block DC, pass AC
- Bypass (decouple) for low-impedance AC path
- Couple signals between circuits
- Filter (widely used on graphics cards)
- Temperature compensation to stabilize circuits
- Timing (paired with resistor to set circuit time constant)
- Tuning for frequency-related devices (mobile phones, radios)
- Rectification, energy storage (for camera flashes, some high-performance models can power a phone for 1 day)
3. Basic Knowledge of Resistor
Core function: Block current flow
1.Resistance value: Unit in ohm (Ω), common units also include kΩ, MΩ
2.Power rating: Common specs 1/16W~2W, exceeding the limit will burn the resistor
By material: Cement resistor (low cost, high power, unstable), carbon film resistor, metal film resistor (high precision, low noise, stable)
By adjustability: Trimmer resistor, adjustable resistor, potentiometer
4. Micro Switch: Definition & Application
A pressure-activated instant quick switch, featuring small contact spacing, short travel, low actuation force, independent of the driving element's movement speed.
Working logic: External mechanical force (via push pin, lever, roller) acts on the reed. When energy accumulates to the critical point, the moving contact connects/disconnects the fixed contact instantly; it resets immediately once external force is removed.
Common variants: Push-pin, roller lever, short/long arm types, available in common and waterproof grades
Main applications: Mice, household appliances, industrial machinery, overcurrent/short-circuit protection, electric turbocharger control systems
