In a power supply, protective functions are a critical set of features designed to safeguard the unit itself--whether it's a DC power supply, AC power source, or high voltage power supply-as well as the connected load (e.g., electronic components, circuits, and equipment) from unexpected, abnormal conditions.
For instance, in the event of an output short circuit, overload, or an internal over-temperature condition, these functions activate instantly. This prevents the degradation or failure of both the power supply and the load while mitigating serious risks such as fire. Ultimately, they are essential for ensuring the overall safety and reliability of your entire system.
Matsusada Precision's power supplies are engineered with a comprehensive suite of advanced protective functions, developed through years of experience, to robustly protect your valuable assets and R&D environment. Note: These protective functions are designed to protect the equipment and circuits, not to provide protection against electric shock to personnel.
Key Types of Protective Functions
Protective functions can be broadly categorized by what they protect: the output, the input and internal circuitry, and the load itself.
Output Protection Features
These functions protect the power supply and the load from abnormal conditions occurring at the output terminals.
- • Overvoltage Protection (OVP)
- Prevents the output voltage from exceeding a preset level. Without it, sensitive electronic components could be instantly damaged by excessive voltage.
- • Overcurrent Protection (OCP)
- Limits the output current or shuts down the output if the current exceeds a preset level. It protects both the power supply and the load from excessive current caused by faults or incorrect connections.
- • Overload Protection (OLP)
- Detects when the output power (Voltage × Current) exceeds the rated limit, then restricts or shuts down the output. This is particularly effective for protecting loads like motors that draw significant power on startup.
- • Short Circuit Protection (SCP)
- Prevents excessive current from flowing when the positive and negative output terminals are short-circuited. This is a fundamental feature to prevent the burnout of internal components.
- • Arc Protection
- A critical function, especially for high voltage power supplies. It detects an electrical arc at the output and instantly shuts down the power to mitigate the risk of major damage or fire.
- • Reverse Polarity Protection
- Protects the power supply and the load from damage if a voltage source, such as a battery, is connected with its polarity reversed.
Internal and Input Protection Features
These functions protect the power supply itself from input line anomalies and internal environmental changes.
- • AC Fault Protection
- Detects abnormalities in the input AC line, such as interruptions or voltage drops (sags), and shuts down the output to prevent unstable operation.
- • Undervoltage Lockout (UVLO)
- Deactivates the power supply's output if the input voltage drops below the minimum level required for stable operation, thereby preventing malfunctions.
- • Over Temperature Protection (OTP)
- Shuts down the output if the internal temperature of critical components like semiconductors exceeds a safe limit. It protects against thermal runaway and component degradation caused by fan failure or high ambient temperatures.
- • Inrush Current Limiting
- Suppresses the large, initial surge of current drawn from the AC line at power-on. This prevents nuisance tripping of circuit breakers and reduces stress on internal components like rectifiers.
Load-Focused Features
- •Soft Start
- Ensures a gradual, controlled ramp-up of the output voltage from zero to the set value upon startup. This significantly reduces electrical stress on loads, especially those with high capacitance or sensitivity to the sudden application of voltage.
The proper design and implementation of these protective functions are the hallmark of a truly reliable power supply. Selecting a unit equipped with the appropriate features for your application is key to ensuring long-term system stability and performance.
- Related words:
-
- Overcurrent Protection (OCP)
- Overvoltage Protection (OVP)
- Overload Protection、Short-circuit Protection
- Arc Protection、Voltage Droop