Analog voltage is a continuous electrical quantity that quantifies the electrical potential difference between two electrical nodes. It is different from a digital level, which is usually a fixed digital voltage level. In analog electronics, the analog voltage is the primary means of measuring circuit performance, although in some cases the analog current is the measurement unit preferred. Nevertheless, the analog voltage signal or analog power is the unit of choice when analyzing most analog circuitry.
For most measurements in electrical and analog electronics, the analog voltage input and output are the most common parameters that determine the condition of a circuit. For instance, when verifying the proper functioning of an isolation transformer, the analog voltage meter is used to measure the input and the output voltage. If there is input voltage and there is no output voltage available, something must be wrong with the transformer.
High voltage analog circuitry is available in electronics appliances and test equipment. The cathode ray tube (CRT) devices, such as television sets and oscilloscopes, use a high-voltage generator used to provide the high voltage for the plate of either a CRT television or a CRT oscilloscope. Usually, the high voltage is generated by making use of a rapidly dropping portion of a sawtooth waveform that makes up the horizontal deflection signal.
Analog voltage converters come in many forms. The alternating current (AC)/direct current (DC) converter accepts AC and provides DC in the output. Power inverters accept DC to produce AC, thus they are also referred to as DC/AC converters that are common in vehicles with 12 or 24 volts direct current (VDC) batteries. These DC/AC converters are also popular in solar photovoltaic energy capture systems. Solar photovoltaic systems convert sunlight into electricity.
In modern electronics, analog voltage is the traditional form of signal or power. In the case of analog power, the means of generation and distribution has been improved over the years, although the same format exists which is mostly sinusoidal or sine waves that cycle through positive then negative, and then repeats. One major advantage of sine wave generation and transmission is the ease of transforming the power into high-voltage versions.
Typically, this requires less current to provide the same power, resulting in smaller wire cross sections required to transfer power across vast distances. Meanwhile, the analog voltage as a signal has mostly remained the same with the added improvement in better signal-to-noise performance. This is largely due to digital methods that employ digital signals in areas where analog signals will incur losses in signal performance. Analog-to-digital and digital-to-analog converters and techniques have greatly improved analog transmission and storage.