摘要:
Disclosed is a fluorescent lamp and ballast arrangement of the type having a lamp base for connection to a fixture that also accommodates a lamp base of an incandescent lamp. A ballast circuit contains a first conversion circuit which converts a.c. voltage to d.c. voltage and which has an electrolytic capacitor for smoothing the d.c. voltage. The ballast circuit further includes a second conversion circuit which converts the d.c. voltage into a.c. current and which includes a resonant inductor and resonant capacitor. A ballast housing has first and second ends spaced along a longitudinal axis of the housing and encloses parts of the ballast circuit. Only two lamp tube portions of the lamp terminate in the first end of the ballast housing, with the resonant inductor being positioned between the two lamp tube portions. Preferably, a pair of printed-circuit boards are positioned within the ballast housing, between the electrolytic capacitor and the resonant inductor, and are dimensioned to convectively shield the capacitor from the inductor and the lamp tube portions. Substantially all ballast components in addition to the resonant inductor and the electrolytic capacitor are preferably sandwiched between the pair of printed-circuit boards. Additionally, the electrolytic capacitor is preferably positioned at least partially within the lamp base. Employing all the foregoing features together has resulted in ballast component temperatures that are equal to, or lower, than ballast component temperatures on comparable high wattage (i.e., greater than about 20 watts) but much larger ballasts that are integral (as here) to the lamp.
摘要:
A fluorescent lamp includes a lamp tube having first and second ends and containing fill materials for causing light generation when provided with electrical power. The lamp further includes first and second power-transferring means at the first and second ends of the lamp tube, respectively, for providing the fill materials in the lamp tube with electrical power. Also included is a thermal heat shield separating the first power-transferring means from ballast circuitry which supplies power to the first power-transferring means and which has a lifetime that becomes substantially less as its operating temperature increases. The thermal heat shield is constructed so that it reflects back to the first power-transferring means and any adjacent portion of the lamp tube sufficient radiant energy to reduce the operating temperature of the ballast circuitry by more than about one degree Celsius compared with the absence of the heat shield.
摘要:
An apparatus for stiffening a circuit board during soldering, assembly, and repair/rework, which includes an elongated crossmember having two opposing ends, an outer support leg extending downward from each crossmember end to form a bridge support with the crossmember and a central support leg extending downward from a central portion of the crossmember. A central portion of the circuit board is attached to the central support member to prevent the circuit board from softening and sagging when exposed to the heat from soldering.