The higher the resistance of the multimeter, the greater the output voltage?
For digital multimeters, the output voltage of the resistance gear is very low due to the amplifier in the meter and also to reduce the power consumption of the meter. The output voltage of 200Ω～20MΩ is only a few tenths of a volt, and only the voltage of the diode and 200M is slightly higher.
The diode gear is to break through the cut-off area of the PN junction, the output no-load voltage is generally above 2.5ⅴ, and the current exceeds 1mA when the test leads are short-circuited. For the 200MΩ gear, since the current passing through the measured resistance is too small, in order to obtain a sufficient sampling voltage drop, the output voltage is about 1.5v, but the current when the test leads are short-circuited is less than 5μA.
Therefore, the output voltage of the resistance gear of the multimeter does not gradually increase with the change of the gear position, but is arranged to meet the normal operation of the multimeter.
In the digital multimeter, the open-circuit voltage of the diode gear is about 2.5V-2.8V, that is, the voltage between the VΩ hole and the COM hole is about 2.5V-2.8V, and the open-circuit voltage of all ranges of the resistance gear is about 0.3V-0.6V, and the current of each gear is correct. is different, and you need to measure it yourself.
