Ametherm SL15 40004

The SL15 40004 inrush current limiting thermistor from Ametherm offers a maximum steady state current of 4A (up to +25°C), resistance of 40Ω ±20% (at 25°C) and a maximum recommended energy rating of 35J. The Ametherm SL series suppresses surge currents that occur when electrical circuits are switched on, preventing serious damage to sensitive electronic components if their rated current values are exceeded. Connected in series with the load, at “switch-on” they limit the current due to its relatively high cold resistance. As a result of current flow, the thermistor self-heats and in turn reducing its resistance value so that once the initial surge current has been safely held off, the resistance in the thermistor is maintained at a low value to maximise efficiency

• Inrush current limiting thermistor
• Resistance of 40Ω (at 25°C)
• Maximum steady state current of 4A (up to +25°C)
• Maximum recommended energy of 35J
• Actual energy failure at 70J
• 0.3Ω at 100% maximum current and 0.9Ω at 50% maximum current
• Body temperature of +178°C at maximum current
• Dissipation constant of 27mW/°C
• Tolerance ±20%
• Thermal time constant of 48mW/s
• Material Type G (for Beta and Curve)
• Recognised by Underwriters Laboratories (UL) for ensured safety
• Maximum disc diameter 15mm

Typical applications for the SL series include:

• Limit current inrush to PSUs and battery chargers
• Lighting circuits and thermostat protection
• Electric motor soft start

The below table gives the full specifications of the Ametherm SL15 40004 series: