Alternating Current (AC) - current that reverses direction on a regular basis (usually 60 times per second in the United States). Measured in amps.

AC Power Source - an instrument that takes one AC voltage and frequency level and converts it into another AC voltage and frequency level.

Amplifier - a circuit that boosts an input signal from one level to another.

Apparent Power - the total power generated or consumed by a device due to real and reactive circuit components. Measured in VA (volt-amps).

Complex Power - the vector sum of the real and reactive power components of a circuit. Measured in VA (volt-amps).

Crest Factor - the ratio of peak current (Apeak) to RMS current (Arms).

Direct Current (DC) - current that only flows in one direction. Direct current comes from a polarized source, meaning one terminal is always at a higher potential than the other. Measured in amps.

Frequency - the number of times a waveform completes a cycle in a period of time. Measured in hertz.

Inrush Current - a term used to describe the current needed to power a load upon start-up. Some loads require a large/inrush starting current in order to operate.

Linear Power Source - a power source that linearly amplifies the input signal using transistors to increase the voltage, current and power output of the system.

Modular - capability that allows the operator to interconnect multiple 300XAC power sources in order to increase the power output or power configuration beyond that of a single instrument.

OC Fold - over current fold back is a technology used in power sources that keeps output current constant by reducing the voltage in order to power loads that may have a high inrush current.

Parallel Mode - up to 3x 300XAC modular AC power sources can be configured with their outputs tied in parallel, allowing for the system to output three times a single instrument's nominal output current rating.

Phase Angle - the degree of measurement that corresponds to an AC waveform's amplitude. Measured from 0 - 360 degrees.

PLC - Programmable Logic Control is an automation method using relay or digital technology.

Polyphase Mode - multiple 300XAC modular AC power sources can be configured to provide output voltages of up to 600VAC (output configured for 1Φ3W) or provide 3Φ output power (output configured for 3Φ4W).

Power - a generic term used to describe electrical work being done. There are many types of power, including real power, reactive power, apparent power, and complex power.

Power factor - the ratio of real power (watts) to apparent power (VA). Based on a scale from 0 to 1 to determine how reactive and resistive a load is.

Reactive Power - the power absorbed by capacitive or inductive elements in a circuit. This power does not work. Measured in VAR (volt-amps reactive).

Real Power - the power that performs work in a circuit. Measured in watts.

Response Time - the time that is needed to regulate the voltage, current, frequency, and power output when a load is added to the power source.

Safety Agency Listing - a safety mark given to a product that has met stringent benchmarks as classified by the authorized agency.

smartCONFIG® - this feature enables the operator to change the output of linked 300XAC modular AC power sources from Parallel to Polyphase modes with a simple button push. No changing cables or test fixtures is required.

smartDETECT® - this feature automatically determines how many 300XAC modular AC power sources are connected together in a power system. After the check is completed the 300XAC Series will automatically change the programming output function based on the number of interconnected sources in the system.

smartVOLT® - an exclusive APT feature that allows the operator to configure the VariPLUS to power up at 0 volts or the previously used voltage before the instrument was turned off.

Start/End Angle - an APT feature that allows the operator to specify at which phase angle the output waveform begins and ends.

Steady State Current r - a term used to describe the current when the load is running nominally after the inrush current.

Surge/Drop - an APT feature that allows the test operator to simulate loading, brown-outs, and voltage dips and spikes.

Switching Power Source - a power source that uses switching technology (integrated circuits and components) to increase the voltage, current and power output of the system.

Synch Output - an APT feature that provides a 5V output signal which can be used to trigger a Programmable Logic Controller (PLC) device.

Total Harmonic Distortion (THD) - a percentage that is used to identify the degree of the noise/unclean signal in a power source's output waveform.

Transient - a temporary change in voltage or current that can occur which may alter the behavior of a DUT. APT instruments can simulate these conditions with our Surge/Drop feature.

Voltage - the amount of force that is needed to move current from point to point. Measured in volts.