What Is a Voltage Detector?
A voltage detector is an electronic device used to detect specific voltage levels.
It monitors whether the power supply voltage is within a specified range, ensuring stable operation and proper control.
Uses of Voltage Detectors
Voltage detectors are crucial in monitoring and controlling power supply stability, ensuring system reliability and safety.
1. Reset Circuits for Microprocessors
They monitor supply voltage and generate a reset signal at the proper voltage level, especially during power-on, allowing microcontrollers or microprocessors to initialize successfully and start from a reset state.
2. Control of Power Supply Units
Integrated into power supply units, voltage detectors detect power supply voltage abnormalities and control the circuit to maintain stable power.
3. Battery Management Systems
In battery management systems, voltage detectors monitor battery voltage, detecting overvoltage or undervoltage during charging or discharging, aiding in stable battery operation.
4. System Fail-Safe Functions
They are also employed in system fail-safe functions, safely shutting down systems or activating protective functions upon detecting power failures or unstable voltages.
Principle of Voltage Detectors
Voltage detectors contain a circuit that detects voltage levels at the input terminals. Their typical configuration and operating principle include:
1. Reference Voltage Source
They require a stable, accurate reference voltage for comparison with the input voltage, either produced internally or supplied externally.
2. Comparator
Comparators within voltage detectors compare the input voltage with the reference voltage, outputting the result.
3. Threshold Setting
They set a threshold voltage as the reference. The comparator then determines if the input voltage is above or below this threshold, making a stable threshold voltage crucial.
4. Output Signal
Voltage detectors output a digital signal indicating whether the input voltage is above or below the threshold, which is crucial for monitoring and controlling power supply stability.
Types of Voltage Detectors
Various types of voltage detectors exist, each with specific applications:
1. Fixed-Type Voltage Detector
Fixed threshold voltage detectors are used for power supply monitoring and reset signal generation.
2. Variable-Type Voltage Detector
Variable-type detectors allow users to adjust the threshold voltage, which is suitable for monitoring diverse voltage levels.
3. Dual Voltage Detector
Dual voltage detectors have two independent thresholds for monitoring and controlling different voltage levels.
4. Overvoltage Detector
Specialized for detecting overvoltage, these detectors activate countermeasures when the input voltage exceeds a set threshold.
5. Low-Voltage Detector
Designed for low voltage detection, they trigger countermeasures like current supply limitation when the input voltage falls below a specified threshold.
6. Reset IC
Mainly used in microcontrollers and microprocessor reset circuits, they detect when the power supply stabilizes and outputs a reset signal, initiating normal operation.