half power point - A frequency at which the power is 50% of maximum. This corresponds to 70.7% of maximum current or voltage.
h-parameters - (hybrid parameters) Transistor specifications that describe the component operating limits under specific circumstances.
half wave rectifier - A diode rectifier that converts AC to pulsating DC by eliminating either the negative or the positive alternation of each input AC cycle.
harmonic - Sine wave that is smaller in amplitude and some multiple of a fundamental frequency. Example: 880 Hz. is the second harmonic of 440 Hz., 880 Hz. is the third harmonic of 220 Hz.
hartley oscillator - An oscillator that uses a tapped inductor in the feedback network.
henry - The basic unit of inductance.
HERTZ - (Hz.) Unit of frequency. One hertz is equal to one cycle per second.
high fidelity - (Hi Fi)Sound reproduction equipment that reproduces sound as near to the original sound as possible
high-pass filter - A tuned circuit designed to pass all frequencies above a desnigated cut-off frequency. Frequencies below the cut-off frequency are rejected or attenuated
high tension - Lethal voltage in the kilovolt range and above.
hole - A gap left in the covalent bond when a valence electron gains sufficient energy to jump to the conduction band
hologram - Three-dimensional picture created with a laser.
holography - The science dealing with three-dimensional optical recording.
horizontally polarized wave - Electromagnetic wave that has the electric field in the horizontal plane.
hybrid circuit - Circuit that combines two technologies (passive and active or discrete and integrated components) onto one microelectronic circuit. Passive components are usual made by thin film techniques, while active components are made with semiconductor techniques.
hysteresis - Amount that the magnetization of a material lags the magnetizing force due to molecular friction. In Schmitt Trigger circuits, the difference between the upper and lower trigger points.