Solar grid-tie inverters and variable frequency drives (VFDs) for HVAC systems.
| Device | Fully name | Controlled by | Voltage blocking | Typical frequency | Best for | | :--- | :--- | :--- | :--- | :--- | :--- | | | – | Uncontrolled (on/off by current) | Up to several kV | Up to MHz | Rectification | | BJT | Bipolar Junction Transistor | Current (base) | Medium | Low (<20 kHz) | Obsolete, but learning base | | MOSFET | Metal Oxide Semiconductor FET | Voltage (gate) | Low to medium (<1 kV) | High (100 kHz – MHz) | Low voltage, high freq. | | IGBT | Insulated Gate Bipolar Transistor | Voltage (gate) | High (600V – 6.5 kV) | Medium (2–50 kHz) | High voltage, medium freq. | power electronics 1
| Conversion Type | Input → Output | Common Name | Example Application | | :--- | :--- | :--- | :--- | | | Mains AC → DC | Rectifier | Phone charger, DC motor drive | | DC-DC | DC voltage (e.g., 12V) → Different DC (e.g., 5V) | Chopper / Regulator | Laptop voltage regulator module | | DC-AC | DC battery → AC sine wave | Inverter | Solar inverter, UPS, EV motor drive | | AC-AC | AC voltage (e.g., 220V) → Different AC (e.g., 110V) | Cycloconverter | AC motor speed control (low freq.) | | | Conversion Type | Input → Output
Power Diodes: The simplest switches, used for rectification. 12V) → Different DC (e.g.