Portable fluorescent task lamp
There is disclosed a portable hand held fluorescent task lamp comprising an elongated plastic housing having a clear lens on one end of the housing and a hand grip portion formed into the second end of the housing; a line cord; at least two compact fluorescent lamp (“CFL”) bulbs removably disposed behind and visible through the clear lens, of any wattage from approximately four to thirty watts and of either a non-starting type or a self-starting type; an electronic ballast circuit; and an SPST function switch disposed in series with each CFL bulb, wherein the CFL bulbs may be ignited and sustained in illumination in parallel, simultaneously or individually, as determined by the respective SPST switches.
1. A portable hand held fluorescent task lamp, comprising:
an elongated housing molded of thermoplastic material and having a clear lens on a first side of a first end of the housing and a hand grip portion formed into a second, opposite end of the elongated housing;
a line cord secured to the second, opposite end of the elongated housing;
at least first and second compact fluorescent lamp (“CFL”) bulbs removably disposed within the first end of the elongated housing behind and visible through the clear lens;
a transformerless electrical drive circuit disposed within the elongated plastic housing, and connected at a first input to a common return node of a power supply connected to the line cord and connected via a common output node to the at least first and second CFL bulbs;
a first lamp circuit including in series connection from the common return node to the common output node a first current limiting inductor, a first node, a first single pole single throw (SPST) switch and the first CFL bulb;
a second lamp circuit including in series connection from the common return node to the common output node a second current limiting inductor, a second node, a second SPST switch and the second CFL bulb;
wherein each first and second SPST switch includes an ON condition and an OFF condition; and
wherein the at least first and second CFL bulbs are ignited and sustained in illumination in parallel, as determined by the respective condition of each respective first and second SPST switches and independent of the starting characteristics of the first and second CFL bulbs.
2. The apparatus of claim 1 , wherein the electrical drive circuit includes a charge pump network for enabling the ignition and continuous illumination of each of the at least first and second CFL bulbs.
3. The apparatus of claim 2 , wherein the charge pump network comprises:
first and second reverse biased diodes connected in series between a positive terminal and a negative terminal of a control portion of the electrical drive circuit, wherein a third node is defined at a junction between the first and second diodes;
a first coupling capacitor connected between the first node and the third node; and
a second coupling capacitor connected between the second node and the third node.
4. The apparatus of claim 1 , wherein the elongated housing includes a reflecting panel disposed behind the at least first and second CFL bulbs disposed within the first end of the elongated housing.
5. The apparatus of claim 1 , wherein the elongated housing includes an actuator switch assembly accessible on an external surface of the elongated housing proximate the hand grip portion wherein further the actuator switch assembly includes the first and second SPST switches for controlling respectively each of the at least first and second CFL bulbs.
6. The apparatus of claim 1 , wherein each of the at least first and second CFL bulbs are twin-tube compact fluorescent lamps having a wattage rating of approximately nine to fifteen watts.
7. The apparatus of claim 1 , wherein each of the at least first and second CFL bulbs are twin-tube compact fluorescent lamps having a wattage rating of approximately four to twenty-four watts.
8. The apparatus of claim 1 , wherein each of the at least first and second CFL bulbs are quad-tube compact fluorescent lamps having a wattage rating of approximately five to thirty watts.
9. The apparatus of claim 1 , wherein each of the at least first and second CFL bulbs are compact fluorescent lamps, each having a wattage rating of approximately four to thirty watts.
10. The apparatus of claim 1 , wherein the transformerless electrical drive circuit provides for preheat, ignition, and run modes of operation of the at least first and second CFL bulbs.
11. The apparatus of claim 1 , wherein a control portion of the transformerless electrical drive circuit is an integrated circuit having a Vcc terminal connected to a positive supply voltage, a Vss terminal connected to a supply voltage return and providing preheat, ignition, and run modes of operation of the at least first and second CFL bulbs.
12. The apparatus of claim 1 , wherein the electrical drive circuit is powered by a 120 VAC or 240 VAC line voltage provided by the line cord connected to the power supply.