Signal converters are electronic devices that receive one type of signal and output another type of signal. Common features include filtering and amplification or attenuation. Integral filters allow some signal frequencies to pass while attenuating others. Integral amplifiers multiply signals to the matching scale of the input device. For signal reduction, amplifier gains or multiplication factors may be greater than one or fractional. Signal isolation can be achieved through optical isolation, magnetic induction, or the use of capacitors. Inputs for signal converters include AC and DC voltages, AC and DC currents, charges from piezoelectric devices, and frequencies and other specialized waveforms. Signal converters that include multiplexers can combine several AC or DC inputs serially into one output.
There are several types of signal converters. Analog-to-digital converters (ADCs) sample analog signals and convert them to a series of digital values. By contrast, digital-to-analog converters (DACs) convert digital numbers into corresponding voltage or current levels. Frequency converters or translators convert or scale input frequencies to specific output frequencies. Voltage converters accept voltage inputs and provide scaled voltage outputs by using conversion types such as voltage doubling and inversion. Frequency-to-voltage converters provide analog voltage outputs that are a function of input signal frequency. Voltage-to-frequency converters provide sine wave, pulse train, or pulse width modulation (PWM) outputs that are a function of input signal voltage. Other types of signal converters include current-to-voltage converters, which produce output signal voltages that are a function of the input current, and current loop converters that convert an analog or digital signal to a current loop output such as 4 – 20 mA or 0 – 20 mA. Charge converters are devices that convert the charge output from piezoelectric or other charge-producing sensors to signals such as analog voltage or current.
Signal converters are electronic devices that receive one type of signal and output another type of signal. Common features include filtering and amplification or attenuation. Integral filters allow some signal frequencies to pass while attenuating others. Integral amplifiers multiply signals to the matching scale of the input device. For signal reduction, amplifier gains or multiplication factors may be greater than one or fractional. Signal isolation can be achieved through optical isolation, magnetic induction, or the use of capacitors. Inputs for signal converters include AC and DC voltages, AC and DC currents, charges from piezoelectric devices, and frequencies and other specialized waveforms. Signal converters that include multiplexers can combine several AC or DC inputs serially into one output.
There are several types of signal converters. Analog-to-digital converters (ADCs) sample analog signals and convert them to a series of digital values. By contrast, digital-to-analog converters (DACs) convert digital numbers into corresponding voltage or current levels. Frequency converters or translators convert or scale input frequencies to specific output frequencies. Voltage converters accept voltage inputs and provide scaled voltage outputs by using conversion types such as voltage doubling and inversion. Frequency-to-voltage converters provide analog voltage outputs that are a function of input signal frequency. Voltage-to-frequency converters provide sine wave, pulse train, or pulse width modulation (PWM) outputs that are a function of input signal voltage. Other types of signal converters include current-to-voltage converters, which produce output signal voltages that are a function of the input current, and current loop converters that convert an analog or digital signal to a current loop output such as 4 – 20 mA or 0 – 20 mA. Charge converters are devices that convert the charge output from piezoelectric or other charge-producing sensors to signals such as analog voltage or current.
Performance specifications for signal converters include the number of analog channels and the number of differential channels. When single-ended outputs are available, suppliers often specify the maximum number of analog channel outputs as twice the number of differential outputs. Differential channels, which have two inputs, define the voltage as the signal to process between the two inputs. Other performance specifications for signal converters include accuracy and resolution. Accuracy, which is represented as a percentage of a full-scale measurement range, depends on signal conditioning linearity, hysteresis, and temperature considerations. Reference refers to the degree of fineness of the digital word representing the analog value.
There are a variety of form factors for signal converters. Some devices mount on integrated circuits (ICs), standard DIN rails, or printed circuit boards (PCBs) that attach to enclosures or plug into computer backplanes. Others bolt into walls, cabinets, enclosures, or panels. Rack-mounted units fit inside a standard 19” telecommunications rack. Modular styles include stackable units that dock in bays, slots, or boxes. Benchtop or freestanding signal converters often feature full casings or cabinets and integral interfaces. Some devices allow users to make adjustments from a local interface such as a front panel. Others provide a computer interface, touch screen, or remote handheld device.