Thermistor PTC 375Ohm 2-Pin Radial T/R

Positive temperature coefficient (PTC) thermistors for overload protection have proved to be the ideal electronic ballast component for increased lamp life-time.When the rectified mains is first applied, the PTC thermistor is cold, so its resistance is low. The lamp voltage will be below the necessary ignition value, so the current will flow through the cathodes, heating them to their emission temperature. At the same time, the PTC thermistor will heat up to its switch temperature, whereupon its resistance will rise rapidly, allowing the lamp voltage to reach its ignition value and light the lamp.Once the lamp is lit, the cathodes are fed by a high-frequency lamp supply, to avoid flicker and improve efficiency. The PTC thermistor plays no further part until the lamp is switched off, whereupon it is ready to resume its smooth-starting function.We supply a range of lighting PTC thermistors for this application offering a wide choice of voltage and switch times.

• Reliable lamp starting, due to well defined inrush-current generated time delay
• Accurate resistance for ease of circuit design
• Small size and durable
• Available bulk-packed or taped-on-reel
• Long life: More than 20 000 starts for a 20 W CFL lamp