Low Cost Digital Multimeter (DMM)

Jargon buster

Plain-language definitions for the technical terms used above.

banana plug

A banana plug is a common 4 mm connector used on bench power supplies, multimeters and lab test leads, pushing into a matching banana socket. Where terminals use banana plugs or sockets, you can connect standard 4 mm test leads and adapters without soldering.

DC

DC means direct current, where electricity flows in one constant direction, as supplied by batteries, USB ports and many plug-pack power supplies. When a product specifies DC, it runs from a DC supply rather than mains AC, so you need to provide the correct voltage and polarity.

LCD

LCD stands for liquid crystal display, a screen technology that uses a backlight and liquid crystals to show images or text. It matters because LCD modules usually need a display driver and enough controller pins or a bus interface to send image data.

LED

A light-emitting diode (LED) is a small electronic component that emits light when current flows through it in the correct direction. Because it only conducts one way, its polarity matters, and a through-hole LED must be soldered the correct way around to light up.

RMS

RMS is a way of describing the effective level of an AC signal, such as an audio output voltage. It helps compare audio output levels more meaningfully than a peak voltage number.