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Remote control or digital multimeter

Short answer

A digital multimeter measures voltage, current, and resistance by converting each to a small DC voltage via a range selector (attenuator, shunt, or constant current source). After signal conditioning, an ADC digitizes the voltage, and a decoder drives the LCD display, providing high accuracy and auto-polarity.

Explain briefly about remote control or digital multimeter with necessary diagrams.

The question allows a choice; the digital multimeter is explained here.

A digital multimeter measures voltage, current and resistance and shows the result as digits on an LCD or LED display.

Block diagram

 Input -> Range      -> Signal     -> ADC -> Decoder/ -> Display
          selector      conditioner         driver
          (atten.,       (amp, AC/DC)
           shunt)
             ^                         ^
             +--- Control logic, clock, reference ---+

Working

  1. Range selector: attenuator for voltage, shunt resistor for current, and constant current source for resistance; this converts every measured quantity into a small DC voltage.
  2. Signal conditioner: amplifies the voltage; for AC, a rectifier converts AC to DC (RMS converter).
  3. ADC: converts the DC voltage to a digital number (dual-slope ADC is common, giving good noise rejection).
  4. Decoder and driver: convert the digital number to the seven-segment code and drive the display.
  5. Control logic and clock: provide the timing and the reference voltage.

Features: high accuracy, input impedance of about 10 MΩ, auto-polarity and auto-range, no parallax error. Also, it can test diodes and continuity.

✓ Answer checked by Claude Opus 5.5 (high effort)

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