SU464866A1 - Digital ohmmeter - Google Patents

Description

When the key is in position b, the reversible counter 5 works on subtraction. Measured resistance is excluded from the measuring circuit.

The number Ni is subtracted from the number V already recorded on the counter during TI. By the end of the time interval T + TI, the number Nn will be recorded on the counter.

N N-N, R

KlU

Where

reference frequency generator;

the coefficient determining the relationship between the input signals of the pulse frequency modulator;

duty cycle of the generator of the reference frequency;

power supply voltage.

Subject invention

A digital ohmmeter containing a frequency pulse modulator, a constant source

voltage, reference frequency generator, coincidence circuit, reversible counter, control device and switch, characterized in that, in order to reduce measurement error, the common contact of the switch is connected to one of the inputs of the frequency-pulse modulator, the second contact of the switch corresponding to the normal open state, connected to one of the terminals of the measured resistance, the other terminal of which is connected to the third contact, corresponding to the normally closed state, while the input of the circuit adenomas connected to a first input of down counter, whose second input

connected to one of the outputs of the control unit.