Practical component map
This page is a basic component map bundling the section-3 'practical circuits' slides of the kickboard embedded course onto one page, covering passive components (resistor, capacitor, inductor), the five diode types, transistors (BJT, MOSFET), and power circuits (buck, boost) — all against the real kickboard board. Rather than memorizing hand-calculations like an electrician-exam textbook, the point is to build a selection-and-design intuition for how to pick and place components, using real cases such as SMD parts, battery voltage division, the 940µF input capacitor, a shunt, and the MOSFET inverter. It is the entry point to read as a 'whole map' before digging into any single topic.
Component map — passive, diode, transistor, power
- Electrical components split broadly into passive parts that need no operating voltage (resistor, capacitor, inductor) and active semiconductor parts that do (diode, BJT, MOSFET).
- The MOSFET, a voltage-controlled switch, is the hub of this map, branching up into digital logic and down into buck/boost power circuits.
- Diodes and inductors also feed into the power circuits, taking part in buck/boost operation through rectification and energy storage.
Passive — resistor, capacitor, inductor
- Resistors handle current limiting (LED), pull-up/pull-down, voltage division (battery→ADC), and shunting (current sensing); real resistors carry parasitic L and C, affected at high frequency.
- The kickboard input DC is backed by 940µF — two 470µF electrolytics in parallel — and capacitors also serve decoupling, bypass, and RC filtering.
- Inductors store energy in the buck converter and dissipate high-frequency noise as heat via beads, but above the saturation current the flux stops increasing and the DCR causes heating.
- → 1.83V (within ADC range)
- → 2.58V (within ADC range)
Five diodes · transistors (BJT · MOSFET)
- Diodes conduct forward at about 0.7V and block reverse; the five types are general (rectifying), switching (1N4148), Schottky (SS14, 0.2~0.6V forward), Zener (reverse clamping), and TVS (surge/ESD absorption).
- The BJT is a current-controlled device controlling collector current via base current (I_C = I_B × h_FE), operating at saturation Vce≈0.2V when switching.
- The MOSFET is a voltage-controlled switch and the core part of a 3-phase inverter; it needs Vgs of 12~15V, so the MCU cannot drive it alone, making a gate-driver IC essential.
| BJT | MOSFET | |
|---|---|---|
| Control | by base current | by gate voltage |
| Switching | saturation Vce≈0.2V | ohmic, low Rds(on) |
| Drive | I_C = I_B × h_FE | Vgs 12~15V → gate driver |
Power circuits — buck step-down, boost step-up
- Power circuits divide into linear regulators (low noise, precise, but hot and inefficient) and switching regulators (DC-DC: efficient, step up or down, but with switching noise and more parts).
- Buck (step-down) makes Vout < Vin through an inductor and boost (step-up) makes Vout > Vin, both toggling the switch On/Off.
- The core of the buck converter is volt-second balance — the On and Off areas of the inductor voltage must match — and a synchronous buck improves efficiency by replacing the diode with a MOSFET.
Do not forget this slide is an 'overview (map),' not deep theory — a deep grasp of each component must be filled in through the course and AI micro-study on separate pages. The items the slide defers to 'covered in detail later' — OP-AMP current sensing, the placement and commutation of the six MOSFETs in a 3-phase inverter, and gate-driver IC design — are absent here, so do not mistake this map for finished real-world design.