In the world of electronic switches, the same switch cannot handle all currents. 

The requirements for contacts carrying milliampere signals versus 20-amp currents are vastly different. 

Here's how we engineer them.

1. Contacts: The "Heart" of the Switch

Core mission:

· When closed: Transmit current with minimum resistance

· When open: Quickly interrupt current and suppress arcing

Different current levels present completely different challenges.

2. Micro-Current (<100mA): Signal Integrity

Challenge: Silver contacts form an oxide film in air. Milliampere current can't break through it, causing signal loss.

Our Solutions:

· Gold-plated contacts (0.1-3μm): Never oxidize, stable resistance

· Dual-contact design: Redundancy ensures conduction

· Contact pressure: 30-50g, enough to pierce oxide film

Field Case: Medical device signal loss solved-our gold-plated switches maintained <5mΩ fluctuation after 1M operations.

3. Medium Current (0.1A-5A): The Balance

Challenge: Heat appears, arcing begins. Need balance between conductivity, arc resistance, and wear.

Our Solutions:

· Silver alloys: AgSnO₂ (eco-friendly), AgNi (stable resistance)

· Composite rivet contacts: Silver alloy head + copper base

· Contact pressure: 80-150g, gap: 0.5-1.2mm

4. High Current (5A-20A): Heat vs. Arc

Challenge: Strong arcs erode contacts; heat quadruples when current doubles (P=I²R); contacts may weld.

Our Solutions:

· Specialty materials: AgSnO₂In₂O₃ (30% longer arc life), AgW (melting point 3422°C)

· Hemispherical contacts: Higher unit pressure, 200-300g force

· Arc suppression: Magnetic blowout, quick-break mechanism

Real Data: Our 20A switch achieved:

· 10,000 cycles resistive load

· Temperature rise <35K after 1hr at 20A

· Withstood 60A impact without welding

5. Material Selection Guide

Current Range Recommended Material Application

<100mA Gold-plated phosphor bronze Signal transmission

0.1A-2A AgNi10 Control panels

2A-5A AgSnO₂ Power switches

5A-10A AgSnO₂In₂O₃ Power tools

10A-20A AgW + arc suppression Industrial equipment

6. Common Misconceptions

❌ "Silver contacts are always better"

Fact: Pure silver is soft and sulfidizes. We use silver alloys.

❌ "High-current switch works for low current"

Fact: May fail due to oxide film issues. Vice versa.

❌ "Bigger contacts = better"

Fact: Oversized contacts increase force, reduce life.

❌ "Same material = same performance"

Fact: Processes matter-powder metallurgy, heat treatment, bonding strength.

7. Our Quality Commitment

Every switch undergoes:

· Spectrometer analysis: Material composition verified

· Contact resistance: 100% inspected

· Temperature rise: Regular sampling

· Life testing: 24/7 continuous verification

From milliamps to 20 amps, contacts carry more than current-they carry reliability. Choose wisely.

Need the right switch for your current? Contact our technical team.