Frequency converters are used to scale-up or scale-down the frequency of an input signal. The output signals are a function of the input and there are no distortions in the phase angle.
While selecting a frequency converter, you need to consider the number of analog input channels that will be used. Single-ended is used for single-ended channels. In differential channels the output is the difference between two input signals. The device can run on AC voltage or current as the input.
There are different styles of frequency converters to choose from. These include IC or board mount, circuit board, panel or chassis mount, modular bay or slot system, DIN rail, rack mount, and stand-alone. There are also several user interface choices for frequency converters. These include none, front panel and display, touch screen, handheld or remote programmer, and computer programmable.
Some other important features to look for in frequency converters are:
- bandwidth, which is the difference in the low and high limiting values of the response frequency;
- accuracy, which depends on the temperature, signal linearity, hysteresis;
- signal isolator in which contact between the signal and electrical signal is removed.
The filter is also an important element to consider when searching for frequency converters. Considerations should include integral filters, filter architecture, filter function, low pass cutoff frequency, high pass cutoff frequency, and programming. A filter can be an integral type in single phase or multi phase and can be an analog or digital model or an RC, FIR, or IIR. A filter can also be of low pass, high pass, band pass, band stop or all pass. The converter can have a front panel display or can be computer programmable. A filter will allow certain signal frequencies to pass while holding up others.
Amplifier specifications for frequency converters are also important factors to consider. An amplifier is designed to multiply a signal to the matching scale of the input device. Amplifier gains, or multiplication factors, may be greater than one or fractional for signal reduction. Amplifier gain may also be adjusted depending on the application needs. This adjustment may be from a local interface or from a computer interface. Gain is the factor by which the input signal is multiplied.