What Is a Voltage Detector?
A voltage detector is a device used to detect supplied voltage. It is a type of device used in electrical circuits and electronic equipment.
It is primarily used to monitor fluctuations in voltage signals or the exceeding of certain thresholds. This is often used to ensure proper operation and protection of electronic equipment.
Uses of Voltage Detectors
Voltage detectors are used in a variety of applications. The following are examples of typical uses of voltage detectors:
1. Power Supply Management
Voltage detectors are used in power supply circuits. They detect voltage fluctuations and abnormalities and control the switching of power supplies and triggering of protection circuits.
They are often used to ensure a stable power supply, for example, by switching an auxiliary power supply when the voltage drops.
It is also used to monitor battery charge status and voltage levels. To prevent overcharging or over-discharging of batteries, voltage detectors can be used for proper charge control and warning functions. They are also used to display the remaining battery level and determine when to replace the battery.
2. Overvoltage Protection
They are used for protecting circuits and equipment from overvoltage. When a voltage exceeding a specified threshold is detected, a protective circuit is activated to shut down the circuit or take other measures. This prevents electronic equipment and circuits from breaking down.
3. Automobiles
Voltage detectors are also widely used in automotive applications. Electronic control systems are a key component of automobiles, and accurate voltage monitoring is necessary to ensure safety and comfort.
The vehicle battery is required for engine starting and electronic equipment operation. Voltage detectors monitor the battery’s state of charge and abnormal voltage levels to help determine appropriate charge control and battery replacement.
In electric vehicles, they are often used to check the remaining charge of the motor drive battery. In addition, various electronic control units in vehicles control the engine, brakes, airbags, etc. Voltage detectors monitor the power supply voltage of these control units and contribute to proper operation and detection of abnormalities.
Principle of Voltage Detectors
A voltage detector is a device that compares an input voltage with a preset threshold value. The output of the detector changes depending on whether the input voltage is above or below the threshold.
Although specific methods and devices may vary, voltage detection is based on this principle. When the input voltage exceeds the threshold, a detection is made and control and other actions are performed accordingly.
Types of Voltage Detectors
There are various types of voltage detectors. The following are examples of typical types of voltage detectors:
1. Comparator
A comparator is a device that compares an input voltage with a reference voltage and changes the output based on the relationship. The output is switched depending on whether the input voltage is above or below the reference voltage. It is commonly realized using an operational amplifier.
Comparators not only detect whether the input voltage is above or below a specific threshold, but may also have features such as anomaly detection and hysteresis. This allows them to be used in a wide variety of applications.
2. Zener Diode
A zener diode is a diode with the characteristic of conducting when the reverse voltage exceeds a specific level. In a voltage detector, a zener diode is designed to allow current to flow when a specific voltage level is exceeded.
The zener diode has a very simple construction. They do not require any additional electronic circuitry or components because they start conducting when the reverse voltage exceeds a specific level. Leakage current is also very low, minimizing power consumption.
3. Relay
A relay is a device in which a voltage is applied to an internal coil and a signal is transmitted in response to the voltage level. By using instrument transformers, it can be applied to high voltages. In addition, the coil and the switch section are electrically insulated, and the input voltage and the output section can be isolated and decoupled.
However, since relays are electro-mechanical devices, they have limitations in terms of response speed and life span.