| H, symbol for magnetic field intensity | Historical, nonmechanical memory technologies |
| half-adder | Half-Adder |
| Half-bridge circuit | Strain gauges |
| Half-wave rectification | Other waveshapes |
| | Half-wave rectifier |
| half-wave rectifier | Rectifier circuits |
| | Half-wave rectifier |
| Hall effect | Power measurement |
| Hall-effect sensor | Ammeter impact on measured circuit |
| Hardware vs. Software | Look-up tables |
| Harmonic | Standing waves and resonance |
| | Harmonics in Polyphase Power Systems |
| | Introduction |
| | The TRIAC |
| Harmonic sequence | Harmonic phase sequences |
| Harmonic, even vs. odd | Harmonics in Polyphase Power Systems |
| | More on spectrum analysis |
| | The TRIAC |
| Harmonics | Musical keyboard as a signal generator |
| Harmonics and waveform symmetry | Harmonics in Polyphase Power Systems |
| | More on spectrum analysis |
| | The TRIAC |
| Harmonics, triplen | Harmonics in Polyphase Power Systems |
| | Harmonic phase sequences |
| Headphone | Sensitive voltage detector |
| Heat sink | Rectifier/filter circuit |
| Heater, overload | Contactors |
| Heating, dielectric | Capacitor quirks |
| Heating, inductive | Inductor quirks |
| Hecto | Metric notation |
| Henry | Magnetic fields and inductance |
| | AC Inductor Circuits |
| Heptode | Combination tubes |
| Hertz | Ohm's Law (again!) |
| | Conductance |
| Hexadecimal numeration | Octal and hexadecimal numeration |
| hfe | Active mode operation |
| Hi-pot tester | High voltage ohmmeters |
| High voltage breakdown of insulation | High voltage ohmmeters |
| High, logic level | Digital signals and gates |
| High-impedance output, tristate | Special-output gates |
| high-impedance voltmeter | High-impedance voltmeter |
| high-level programming language | Microprocessor programming |
| high-pass filter | High-pass filters |
| HiPAC-EDT | Infineon HiPAC-EDT |
| history | Early tube history |
| hold time, shift register | Shift Register, Serial-in/Serial-out |
| holding current | The Silicon-Controlled Rectifier (SCR) |
| Holding current, thyristor | Solid-state relays |
| home lab | Setting up a Home Lab |
| horsepower | Power in electric circuits |
| Hot conductor | Single-phase power systems |
| Hot wire | Safe circuit design |
| Hot-cathode tube | Ionization (gas-filled) tubes |
| HPIB | Short-distance busses |
| Hybrid parameters | Active mode operation |
| hydrometer | Electron activity in chemical reactions |
| Hyperbolic function, trigonometry | Complex number arithmetic |
| Hyperbolic functions | Trigonometry Reference |
| Hypotenuse | Trigonometry Reference |
| Hysteresis | Permeability and saturation |
| | Ionization (gas-filled) tubes |
| | Positive feedback |
| | Hysteresis |
| | NOR gate S-R latch |
| | Energy losses |
| | Hysteresis and Eddy Current |
| hysteresis motor | Other specialized motors |
| Hz (unit) | AC Waveforms |
