Voltage-frequency converter

A voltage-frequency converter is a device that converts an electrical voltage into a frequency proportional to it . It is the counterpart to the frequency-voltage converter .

Executions

A voltage-frequency converter works according to the following principle: Due to the input voltage, a proportional electric current flows , which charges a capacitor (linearly over time at constant voltage). When a charge limit is reached, the capacitor is charged in the opposite direction by a short current surge with a fixed duration and level. The higher the input current, the more often counter-charging is required. The frequency of these current surges is proportional to the input voltage.

For use in measurement technology with higher demands on proportionality , a converter is used as in the input stage of the charge balance method .

If the variability of a frequency through the magnitude of an applied voltage is more important than strictly proportionality, the device is called a voltage-controlled oscillator .

Applications

These converters often output a square wave signal. With its two voltage levels, this can be transmitted largely without interference, because the information is not in the signal level or shape, but in the frequency. The converters are used, for example, in sensor circuits or sensors are connected downstream and are therefore used for low-interference analog data transmission .

Since the analog variable frequency can be recorded digitally very easily by counting, converters are also used in analog-digital converters as part of the charge balance method.