How to Check Remaining Battery Power with a Multimeter
A multimeter can not only be used to measure the resistance of the object being measured, but also to measure AC and DC voltages. Even some multimeters can measure the main parameters of transistors and the capacitance of capacitors. Fully mastering the usage of a multimeter is one of the most fundamental skills in electronic technology. Common multimeters include pointer multimeters and digital multimeters. A pointer type multimeter is a multifunctional measuring instrument with the meter head as the core component, and the measured values are read by the pointer on the meter head. The measured values of a digital multimeter are directly displayed in digital form on the LCD screen, making it easy to read. Some even have voice prompts. A multimeter is an instrument that uses a common meter head and integrates a voltmeter, ammeter, and ohmmeter.
The DC current range of a multimeter is a multi range DC voltmeter. The parallel connection of a closed circuit voltage divider resistor in the meter head can expand its voltage range. The DC voltage range of a multimeter is a multi range DC voltmeter. Connecting a voltage divider resistor in series with the meter head can expand its voltage range. The corresponding range varies depending on the voltage divider resistor. The head of a multimeter is a magneto electric measuring mechanism, which can only measure AC power by converting AC power to DC power through diodes.
The basic principle of a multimeter is to use a sensitive magneto electric DC ammeter (microampere meter) as the meter head. When a small current passes through the meter, there will be a current indication. But the meter head cannot pass high currents, so it is necessary to shunt or reduce the voltage by connecting some resistors in parallel or series on the meter head, in order to measure the current, voltage, and resistance in the circuit.
The measurement process of a digital multimeter is converted into a DC voltage signal by a conversion circuit, and then the voltage analog signal is converted into a digital signal by an analog-to-digital (A/D) converter, and then counted by an electronic counter. Finally, the measurement result is displayed directly on the display screen in digital form.
The function of measuring voltage, current, and resistance with a multimeter is achieved through the conversion circuit, while the measurement of current and resistance is based on voltage measurement. In other words, a digital multimeter is an extension of a digital DC voltmeter.
The A/D converter of the digital DC voltmeter converts the continuously changing analog voltage into a digital value, which is then counted by an electronic counter to obtain the measurement result. The decoding display circuit then displays the measurement result. The logic control circuit coordinates the operation of the control circuit and completes the entire measurement process in sequence under the action of the clock.
