Patent Application
20070076386
This invention relates generally to electronic lighting circuit boards, and more particularly to an optimized circuit board with a square foot print.
Electronic ballasts used for powering single fluorescent bulbs have traditionally been formed on an elongate rectangular board because of ease of manufacture and because such a configuration permits ample room for the components and interconnections. For certain customer requirements, however, a square footprint would optimize the space allocation while maintaining the original components of the rectangular board. To convert the board to a square configuration would require that the necessary interconnections would be maintained without crossovers, and that all of the previous components would function in the same relationships as before under the new design. However, conflicts in the transformer can upset the operation of the circuit board and prevent successful operation. Therefore, the present inventor is unaware of any DC light fixture circuit board with an inductor, a resistor, three capacitors, two transistors, a transformer, and three terminal blocks having a square circuit board.
A square layout of a DC light fixture printed circuit board is presented having no cross-over wiring while maintaining all of the necessary component interconnections. The board comprises a transformer, two transistors, a diode, a resistor, an inductor, and three capacitors all arranged on a square 2¼″×2¼″ breadboard. To avoid cross-over wiring, the present inventor has strategically utilized the resistor and two capacitors as “bridges” to complete the necessary connections within the framework of the square configuration. Here, the resistor bridges the connections between the transformer and both the first capacitor as well as the transistor. The second capacitor bridges the connection between the transformer and the inductor, and the third capacitor bridges the connection between the terminal block and the second transistor. The novel configuration achieves the necessary connections in the circuit board while allowing the arrangement of the components in a square footprint.
Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the features of the invention
The challenge in using a square circuit board is that components are bunched together and routing the wiring so as not to overlap other connections becomes problematic. The present invention overcomes this difficulty by strategically using several components themselves as bridges where current is routed not over traces on the breadboard 20 but rather across the elements serving as a bridge.
To accomplish the foregoing circuit on a circuit board having only slightly more than five square inches of available surface area is a difficult challenge that is solved by the present invention. The arrangement of the present invention may be suited for two separate lights each having high and low voltage leads. Referring to
The traces or electrical connections for the arrangement of electrical components in
The inductor L1 is also connected to the third winding T3b of the transformer T1 via trace 58. The terminal block TB1 at the second terminal TB1b is connected via trace 60 to the capacitor C1 at the second terminal C1b, as well as the first transistor Q1 at Q1a. The terminal block TB1 is also connected at the second terminal TB1b to the second transistor Q2 via trace 62 to the terminal Q2a. Capacitor C3 is connected at a first terminal C3a along trace 64 to the first transistor Q1 at terminal Q1c, and also connected at a second terminal C3b along trace 66 to the second transistor Q2 at terminal Q2c. The capacitor C3 is also connected at the second terminal C3b via trace 68 to the first winding T1a of the transformer T1. The first transistor Q1 at terminals Q1b and Q1c is connected to the transformer T1 via traces 70, 72 at T5a and T4a. The transformer T1 at T5a is connected to the terminal block TB2 at terminal TB2b along trace 74, and is connected at T3a to the terminal block TB3 along trace 76 to TB3b.
The transistor Q2 is connected to the resistor R1 along trace 78 between Q2b and R1b, and is connected to the transformer T1 along trace 80 between Q2b and T2a. The transformer T1 is also connected to the terminal block TB2 along trace 82 between T2a and TB2a. The capacitor C2 is connected to the transformer T1 between terminals C2a and T4b along trace 84, and is connected to the terminal block TB3 along trace 86 between terminals C2b and TB3a. The terminal block TB3 is connected to the transformer along three separate traces 88, 90, and 92. Trace 88 connects terminal TB3a to T1b, trace 90 connects terminal TB3c to T2b, and trace 92 connects terminal TB3d to T5b.
With the foregoing connections and couplings, it can be thusly seen that the capacitor C3 serves as a bridge spanning over traces 62 and 66. Moreover, resistor R1 serves as a bridge that spans over traces 70 and 72. Finally, capacitor C2 serves as a bridge that spans over traces 58 and 84. The strategic use of the electrical components to bridge over the traces enables the square configuration to exist. It is also possible to use the inductor L1 to span other traces if necessary, although the example of
The strategic use of the resistor R1, second capacitor C2, and third capacitor C3 to span other traces and serve as a bridge permits the compact arrangement of the electrical components of the present board into a square configuration. Other combinations may be contemplated, where such other combinations would be within the spirit of the invention exemplified by the foregoing example.
