Lamp-life-extender


Posted on Jan 29, 2013

Lamp life can be extended by improving the conditions under which its filament is operated. This includes eliminating the inrush overcurrent surge and reduclog the mechanical stress (vibration) on the filament caused by an ac source. The circuit shown controls the inrush current to the lamp without the 10 to 15 times-rated current stage that normally occurs when power is applied to a cold lamp.


Lamp-life-extender
Click here to download the full size of the above Circuit.

It does so by adjusting the inrush current over time to the inverse of the value normally experienced. RL is a standard tungsten lamp in the range of 15 to 250 W, R is 10-!:J and Rris a negative temperature coefficient resistance that is initially 1.65 M!:J and decreases, by self-heating, to 150 K!:J in approximately 0.5 s. Use of the TMOS device allows high !:J values for R and R T. keeping drive power at a negligible level. This circuit has a number of advantages: very low power dissipation, long life, low-cost components, no significant effect on lamp ratings, negligible effect on efficiency, negligible RFI, and it can be used in hazardous environments.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Flyback converter
Cmos Pair 2-Mhz Crystal Oscillator
Trigger Circuit Controls Stop-Motion Camera System
Servicing the Gottlieb System 1 pinball game
keypad floating voltages
TRIAC Switch To Control High-Voltage Devices
Telephone line based audio muting and light on circuit
HQ Notch Filter Without Close-Tolerance components
The L3 Wire-amplifier NH19-6112
Wien Bridge Oscillator Design
TV audio circuit diagram TA8218AH



Top