In a power supply, protective functions are critical features designed to safeguard the unit itself—whether a DC power supply, AC power source, or high-voltage power supply—and the connected load (e.g., electronic components and circuits) from abnormal operating conditions.
These functions activate immediately in response to events such as output short-circuits, overloads, or internal overheating. By preventing component degradation and failure, they mitigate serious risks, including fire, and ensure the overall safety and reliability of the system.
Matsusada Precision power supplies are engineered with a comprehensive suite of advanced protective functions. Developed through decades of experience, these features provide robust protection for your equipment and research environments. Note: These functions are designed to protect equipment and circuits; they do not provide protection against electric shock to personnel.
Key Types of Protective Functions
Protective functions can be broadly categorized by the area they safeguard: the output, the input/internal circuitry, and the load.
Output Protection Features
These functions protect both the power supply and the load from anomalies at the output terminals.
- • Overvoltage Protection (OVP)
- Prevents the output voltage from exceeding a preset limit. This protects sensitive components from immediate damage caused by excessive voltage.
- • Overcurrent Protection (OCP)
- Limits output current or shuts down the output if current exceeds a preset level. This safeguards the power supply and load against faults or incorrect connections.
- • Overload Protection (OLP)
- Detects when output power (Voltage × Current) exceeds the rated limit, then restricts or shuts down the output. This is particularly effective for loads with high startup power demands, such as motors.
- • Short-Circuit Protection (SCP)
- Prevents excessive current flow when positive and negative terminals are shorted. This is a fundamental feature for preventing internal component burnout.
- • Arc Protection
- A critical function for high-voltage power supplies. It detects electrical arcing at the output and instantly shuts down power to mitigate the risk of damage or fire.
- • Reverse Polarity Protection
- Protects the power supply and load from damage if a voltage source, such as a battery, is connected with reversed polarity.
Internal and Input Protection Features
These functions protect the power supply from input line anomalies and internal environmental changes.
- • AC Fault Protection
- Detects input AC line abnormalities, such as interruptions or voltage sags, and shuts down the output to prevent unstable operation.
- • Undervoltage Lockout (UVLO)
- Deactivates output if the input voltage drops below the minimum level required for stable operation, preventing malfunction.
- • Over Temperature Protection (OTP)
- Shuts down the output if the internal temperature of critical components exceeds safe limits. This prevents thermal runaway and damage caused by cooling failures or high ambient temperatures.
- • Inrush Current Limiting
- Suppresses the initial current surge drawn from the AC line at power-on. This prevents nuisance circuit breaker tripping and reduces stress on internal components.
Load-Focused Features
- • Soft Start
- Ensures a gradual, controlled ramp-up of output voltage upon startup. This significantly reduces electrical stress on loads, particularly those with high capacitance.
Proper design and implementation of these protective functions are the hallmark of a reliable power supply. Selecting a unit with appropriate features for your application is key to ensuring long-term system stability.
- Related words:
-
- Overcurrent Protection (OCP)
- Overvoltage Protection (OVP)
- Overload Protection, Short-circuit Protection
- Arc Protection, Voltage Droop