Precision rectifier

A precision rectifier as a single component does not exist. However, there are electronic circuits which perform the function of a precision rectifier.

In the electrical metrology precision rectifier for low voltage and small Strömstärken are necessary. For silicon diodes commonly used in the measurement electronics are the two most important deviations from ideal behavior (in brackets reference values ​​for 25 ° C)

Where the reverse current rule can be disregarded as a cause of measurement errors, but the forward voltage is very distorting. With the help of feedback operational amplifiers real diodes can also be functionally viewed as an ideal diode. These continue to take the same direction. The operational amplifiers compensates for the forward voltage of the diode by increasing the voltage at its output.

With the almost always permissible approximations of non-overdriven ideal operational amplifier

Independent of, even if it is.

Independently of, and the internal resistance of the ammeter.

The circuits shown behave within certain limits, independent of the load as a controlled ideal voltage source or current source.

These are used for example in rectifier circuits for magnitude formation of AC voltages in multimeters for measuring DC guideline value. While battery-less current and voltage measuring the distortion is captured by the diode by a non-linear at the bottom of calibration in the changing size ranges, using a precision rectifier, the linear division extends continuously to the zero point.

Itemization

• An electronic circuit
• Electrical Measurement