I. Brand and Positioning INFEIMI KSD 01F is a domestic snap-action bimetallic temperature switch (thermostat) with TO 220 plastic encapsulation and straight-through two pins. It features a small size, low cost, and automatic reset, and is used for overheat protection and temperature control in PCBs, power supplies, power amplifiers, and other applications.
II. Operating Principle Core: Bimetallic strip temperature sensing, temperature rise → metal strip deforms and snaps → contact action (on/off); automatic reset after temperature drop.
Normally closed (Type D): Normally conductive → disconnects upon overtemperature → reconnects upon temperature reduction (most commonly used).
Normally open (H type): normally disconnected → overtemperature closed → disconnected when temperature drops.
III. Model and Specification (INFEIMI) Model Examples: KSD 01F D65 (Normally Closed, Acts at 65°C); KSD 01F H80 (Normally Open, Acts at 80°C).
Operating temperature: 25℃～150℃ (commonly used: 40/45/50/65/70/85/95/100℃).
Temperature tolerance: ±3℃ (≤100℃), ±5℃ (>100℃).
Reset temperature difference: approximately 20℃ to 30℃ (e.g., disconnected at 65℃ → reset at approximately 40℃).
IV. Electrical Parameters Contact Load: 220VAC 1.5A/3A; 24VDC 1.5A/3A.
Insulation resistance: ≥100MΩ (at room temperature and humidity).
Contact resistance: ≤100mΩ.
Withstand voltage: ≥1500VAC/1min.
Lifespan: ≥30,000 cycles (under rated load).
Weight: ≈1.8g.
Environmental temperature: -20℃ to +160℃.
V. Structure and Installation Packaging: TO 220 2, plastic encapsulation, two-pin straight insertion, with an insulating shell.
Size: Approximately 10×4×20mm, with a pin spacing of 5mm.
Installation: Ensure the metal surface is tightly attached to the heating element (apply thermal grease), and insert the pins into the PCB or make the wiring.