Basic Electronic Components
This document covers four fundamental electronic components: Resistors, Capacitors, Buttons, and Switches, including common values, formulas, and types.
1. Resistors (R)
Resistors limit the flow of electrical current and dissipate energy as heat.
Common Formulas
- Ohm's Law: $V = I \times R$ (Voltage = Current $\times$ Resistance)
- Series Resistance: $R_{total} = R_1 + R_2 + ... + R_n$
- Parallel Resistance: $\frac{1}{R_{total}} = \frac{1}{R_1} + \frac{1}{R_2} + ... + \frac{1}{R_n}$
Common Values (E12/E24 Series - 5% Tolerance)
Values are multiplied by powers of 10 (e.g., 10$\Omega$, 100$\Omega$, 1k$\Omega$, 10k$\Omega$, 100k$\Omega$, 1M$\Omega$): 1.0, 1.1, 1.2, 1.3, 1.5, 1.6, 1.8, 2.0, 2.2, 2.4, 2.7, 3.0, 3.3, 3.6, 3.9, 4.3, 4.7, 5.1, 5.6, 6.2, 6.8, 7.5, 8.2, 9.1
2. Capacitors (C)
Capacitors store electrical charge in an electric field.
Common Formulas
- Capacitance: $C = \frac{Q}{V}$ (Charge / Voltage)
- Current: $i = C \frac{dV}{dt}$
- Parallel Capacitance: $C_{total} = C_1 + C_2 + ... + C_n$
- Series Capacitance: $\frac{1}{C_{total}} = \frac{1}{C_1} + \frac{1}{C_2} + ... + \frac{1}{C_n}$
- Energy Stored: $W = \frac{1}{2} C V^2$
Common Values
- Ceramic (picoFarads/nanoFarads): 10pF, 22pF, 100pF, 1nF, 10nF, 100nF (often labeled "104")
- Electrolytic (microFarads): 1µF, 10µF, 22µF, 47µF, 100µF, 220µF, 470µF, 1000µF
3. Buttons (Push Button)
A momentary switch that completes a circuit only when pressed.
Common Types
- Normally Open (NO): Circuit is open (off) until pushed.
- Normally Closed (NC): Circuit is closed (on) until pushed.
- Tactile Switch: Small, standard button for PCB mounting.
4. Switches (SW)
An electromechanical device that breaks or connects a circuit, staying in position until flipped.
Common Types
- SPST: Single Pole, Single Throw (On/Off)
- SPDT: Single Pole, Double Throw (Toggle between two paths)
- DPST/DPDT: Double Pole variants (controls two independent circuits simultaneously)
- DIP Switch: Small array of switches for circuit boards.
Quick Reference Summary Table
| Component | Symbol (Ref) | Key Formula | Common Use |
|---|---|---|---|
| Resistor | Zigzag / Box | $V=IR$ | Current limiting, voltage divider |
| Capacitor | Two Parallel Lines | $i=C \frac{dV}{dt}$ | Filtering, timing, coupling |
| Button | Momentary | N/A | User input (momentary) |
| Switch | Toggle/Lever | N/A | Power control, signal routing |
Common Suffixes
- k = kilo ($10^3$)
- M = Mega ($10^6$)
- m = milli ($10^{-3}$)
- µ = micro ($10^{-6}$)
- n = nano ($10^{-9}$)
- p = pico ($10^{-12}$)