RC Absorption/Snubber Circuit Module Relay Contact Protection Resistance Surge

AC/DC 5V-400V RC Absorption/Snubber Circuit Module is an indispensable protective component for power electronics, effectively safeguarding switching devices from destructive voltage transients. This pre-assembled RC snubber module utilizes a series resistor and capacitor network, consequently dampening the high-frequency noise and absorbing the inductive kickback that inductive loads generate when turned off. It also includes a Metal Oxide Varistor (MOV), therefore providing an additional layer of protection against excessive voltage surges. Engineers specifically design this wide-range snubber for use across relay contacts or in parallel with thyristors/triacs in both AC and DC circuits, dramatically extending component lifespan and increasing system reliability. Furthermore, applying this simple module enhances the anti-jamming capability of connected microcontroller circuitry by suppressing electromagnetic interference (EMI).

Key Features:

• Wide Voltage Compatibility: The module operates efficiently across a broad range, supporting AC or DC input voltages from 5 V to 400 V.
• Inductive Kickback Suppression: The integrated RC absorption circuit prevents damage to switching contacts by absorbing the induced electromotive force from inductive loads.
• Built-in Varistor Protection: Includes a Metal Oxide Varistor (MOV) to clamp and prevent excessive voltage fluctuations from causing relay contact adhesion or component failure.
• EMI Reduction: It significantly increases the anti-interference and anti-jamming capabilities of the overall circuit, benefiting nearby sensitive digital components.
• Convenient Wiring: Features simple 2-pin screw terminals for secure and convenient connection in parallel with the switching contacts or load.

Technical Specifications:

• Input Voltage Range: 5 V to 400 V AC/DC
• Maximum Inductive Load Power: ≤ 1000 W (Applicable to typical applications; consult datasheet for specific duty cycles)
• Snubber Resistor Value (R): Typically 220 Ω (±10%)
• Snubber Capacitor Value (C): Typically 0.1 μF (104J) / 630 V (CBB22)
• Varistor Specification (MOV): Typically 10D471K (Nominal 470 V)
• Working Frequency: Suitable for 50 Hz/60 Hz AC systems
• Operating Temperature Range: −40°C to +85°C

Mechanical Specifications:

• Component Type: Pre-assembled Snubber Module PCB
• Connection Type: 2-Pin Screw Terminal (BZ-127 style)
• Mounting: PCB-style mounting or panel mounting via screw holes (if present on the specific variant)
• Component Quality: Utilizes high-quality film capacitor and power resistor for longevity.

Dimensions:

• Module Length: ≈ 34.7 mm
• Module Width: ≈ 14.0 mm
• Module Height (Total): ≈ 17.0 mm (including terminals)
• Weight: ≈ 6 g to 10 g (Extremely lightweight for easy integration)

Pinout and Wiring:

• Terminal 1 (A): Connects to one side of the switching contact (e.g., Common) or one terminal of the Thyristor/Triac.
• Terminal 2 (B): Connects to the other side of the switching contact (e.g., Normally Open/Closed) or the other terminal of the Thyristor/Triac.
• Connection Method: You must connect the module’s two terminals in parallel with the switching contacts (for relays) or in parallel with the Thyristor/Triac device itself.
• Polarity: The module is non-polar and works seamlessly with both AC and DC voltages.

Datasheet Reference:

• Download General RC Snubber Circuit Application Guide (PDF)

Commonly Used in:

• Industrial Control Panels: Protecting contractors and power relays in factory automation systems.
• Solid State Relays (SSRs): Used across the output terminals of SSRs that control highly inductive loads.
• Home Automation Systems: Protecting relays that switch appliances, motors, and lighting circuits.

Applications:

• Relay Contact Protection: Significantly extends the life of mechanical relay contacts by arresting arc generation during switching.
• Inductive Load Switching: Provides necessary damping when switching loads like solenoids, motors, contactors, and transformers.
• Thyristor/Triac Protection: Protects these semiconductor switches from damaging $dV/dt$ and voltage transients.
• Transient Suppression: Helps prevent high-energy voltage spikes from propagating through the system, thus ensuring system stability.

Equivalent Models:

• Custom RC Snubber: A manually assembled series resistor and capacitor is functionally equivalent but lacks the integrated MOV and convenient form factor.
• TVS Diode/Varistor Only: Provides voltage clamping but does not offer the same high-frequency damping characteristics as the RC network.

Package Includes:

• 1 x AC/DC 5V-400V RC Absorption/Snubber Circuit Module