Electrode preheat thermistors for use in compact fluorescent lamps (CFL) and electronic ballasts. Current limiting, time-delayed start-up extends lamp life. Quiet, flicker-free operation. Developed in cooperation with leading ballast designers. Both standard and custom parts are available. Economical, reliable and proven in millions of lamps throughout the world.
Ignition time can be optimized to increase life of lamp. PTC resistance (R25) is chosen, along with filament resistance and application voltage, to control desired electrode preheat current. Lamp preheat time is determined by time required for thermistor to switch from low to high resistance state. Preheat currents shown result in switch times of approximately 1 second at 25�C. Lower currents result in longer switch times.Tinned Copper Clad Steel Wire 24 AWG when 8.5mm 22 AWG when D 10mm
Options: High Temperature Coating Short Clipped Leads Other Wire Forms and Lead Spacings
R25 - Nominal zero power resistance at 25�C. For given diameter, higher resistance thermistors offer higher maximum voltages. Instantaneous Voltage - Maximum rms voltage permitted across thermistor during fluorescent lamp start-up cycle. Continuous Voltage - Maximum rms voltage continuously applied across thermistor during normal lamp operation. Preheat Current - rms current (60Hz) which switches thermistor to high resistance in approximately 1 second at 25�C ambient. Size (mass) of PTC influences rate of I2R temperature increase. For given resistance, larger thermistors have longer switch times. Optional coating slightly increases switch time. Note 6: P/N suffix (not shown) describes wire lead forms and other options.