Improved power supply circuit for electroluminescent light panels operated from low voltage battery source

Claim 2

An improved power supply circuit for electroluminescent lamps used in wristwatches, and other similar low power rated capacitive loads to be operated from low voltage battery power supply sources comprising: first and second gate triggered conducting devices (11, 12) each of the type having first and second terminal electrodes (13, 14) and a trigger gate (15) and which when rendered conductive remain conducting the current flowing through the device drops below a critical holding current value, and conduction through the device ceases; chopper converter means (16, 17, 18) for supplying a relatively high voltage electric potential having a first polarity in common to the first terminal electrodes of the first and second gate triggered conducting devices; means for connecting a capacitive load comprising an electroluminescent lamp (25) suitable for use in illuminating a low voltage battery-powered device load between corresponding second terminal electrodes of the first and second gate triggered conducting devices; first and second switching devices (21, 22) coupled between the respective trigger gates of the gate triggered devices and a source of opposite polarity second potential; a source of first and second 180 degrees out of phase alternating enabling potentials (23, 24) coupled to and controlling alternate periods of conduction of said first and second switching devices whereby said first and second gate triggered conducting devices alternately are enabled to rendered conductive for discrete intervals of time determined by the period of the enabling potentials; said chopper means comprising a voltage step-up flyback converter circuit formed by an inductor (L) and a third switching device (16) connected in series circuit relationship between a low voltage battery source of electric potential and the source of opposite polarity second electric potential, the juncture of the inductor and the third switching device being connected through a diode rectifier (18) to a common terminal conductor buss (19) that is connected in common to the corresponding first terminal electrodes of the first and second gate triggered conducting devices; and a source of high frequency switching signals (20) having a frequency of alternation that is much higher than the out-of-phase alternating enabling potentials coupled to and controlling operation of said third switching device.

Claim 3

An improved power supply circuit according to claim 1 further including a small trigger gate bias capacitor (26) interconnected between the first terminal electrode and the trigger gate of the respective gate triggered conducting devices.

Claim 4

An improved power supply circuit according to claim 1 further including a diode (27) connected between each side of the capacitive load and the juncture of the respective trigger gates of the gate triggered conductig device with the respective first and second switching devices.

Claim 5

An improved power supply circuit according to claim 1 wherein the first and second gate triggered conducting devices each comprise silicon controlled rectifiers and the first, second and third switching devices comprise switching transistors.

Claim 6

An improved power supply circuit according to claim 1 wherein the first and second gate triggered conducting devices each comprise a hooked transistor circuit configuration of P-N-P and N-P-N switching transistors wherein the emitter of the P-N-P transistor (34) is connected to the cathode of a diode (36) and comprise the positive load terminal (13) of the device, the collector of the N-P-N transistor (35) is connected to the gate of the P-N-P transistor, the collector of the P-N-P transistor is connected to the gate of the N-P-N transistor and constitutes the gate (15) of the device, and the collector of the N-P-N transistor constitutes the negative electrode (14) of the gate triggered conducting device, and the first, second and third switching devices comprise switching transistors.

Claim 7

An improved power converter for electroluminescent lamps used in wristwatches, and other similar low power rated capacitive loads to be operated from a low voltage battery power supply source comprising: first and second gate conducting devices each comprising a hooked transistor circuit configuration of P-N-P and N-P-N switching transistors wherein the emitter of the P-N-P transistor (34) is connected to the cathode of a diode (36) and comprises the positive load terminal (13) of the device, the collector of the N-P-N transistor (35) is connected to the gate of the P-N-P transistor, the collector of the P-N-P transistor is connected to the gate of the N-P-N transistor and constitutes the gate (15) of the device, and the collector of the N-P-N transistor constitutes the negative electrode (14) of the gate triggered conducting device; voltage step-up flyback converter means for supplying a relatively high voltage positive electric potential in common to the positive electrode terminals of the first and second gate triggered conducting devices; means for connecting a capacitive load (25) between corresponding negative terminal electrodes of the first and second gate triggered conducting devices; first and second switching devices (21, 22) coupled between the respective trigger gates of the gate triggered devices and a source of negative electric potential; a source of first and second 180 degrees out-of-phase alternating enabling potentials (23, 24) coupled to and controlling alternate periods of conduction of said first and second switching devices whereby said first and second gate triggered conducting devices alternately are enabled to be rendered conductive for discrete intervals of time determined by the periods of the enabling potentials; said flyback converter means comprising an inductor (L) and a third switching device (16) connected in series circuit relationship between a low voltage positive polarity battery source of electric potential and the source of negative electric potential, the juncture of the inductor and the third switching device being connected to the anode of a diode rectifier (18) whose cathode is connected to a common positive polarity potential terminal conductor buss (19) that is connected in common to the positive terminal electrodes of the first and second gate triggered conducting devices; a source of high frequency switching signals (20) having a frequency of alternation that is much higher than the out-of-phase alternating enabling potentials coupled to and controlling operation of said third switching devices, said first, second, and third switching devices comprising of switching transistors; and wherein said gate-triggered conducting devices, said first, second and third switching devices, and said rectifying diodes are manufactured as a monolithic integrated circuit.

Claim 8

An improved power converter for electroluminescent lamps used in wristwatches, and other similar low power rated capacitive loads to be operated from a low voltage battery power supply source comprising: first and second gate conducting devices each comprising a hooked transistor circuit configuration of P-N-P and N-P-N switching transistors wherein the emitter of the P-N-P transistor (34) is connected to the cathode of a diode (36) and comprises the positive load terminal (13) of the device, the collector of the N-P-N transistor (35) is connected to the gate of the P-N-P transistor, the collector of the P-N-P transistor is connected to the gate of the N-P-N transistor and constitutes the gate (15) of the device, and the collector of the N-P-N transistor constitutes the negative electrode (14) of the gate triggered conducting device; voltage step-up flyback converter means for supplying a relatively high voltage positive electric potential in common to the positive electrode terminals of the first and second gate triggered conducting devices; means for connecting a capacitive load (25) between corresponding negative terminal electrodes of the first and second gate triggered conducting devices; first and second switching devices (21, 22) coupled between the respective trigger gates of the gate triggered devices and a source of negative electric potential; a source of first and second 180 degrees out-of-phase alternating enabling potentials (23, 24) coupled to and controlling alternate periods of conduction of said first and second switching devices whereby said first and second gate triggered conducting devices alternately are enabled to be rendered conductive for discrete intervals of time determined by the periods of the enabling potentials; said flyback converter means comprising an inductor (L) and a third switching device (16) connected in series circuit relationship between a low voltage positive polarity battery source of electric potential and the source of negative electric potential, the juncture of the inductor and the third switching device being connected to the anode of a diode rectifier (18) whose cathode is connected to a common positive polarity potential terminal conductor buss (19) that is connected in common to the positive terminal electrodes of the first and second gate triggered conducting devices; a source of high frequency switching signals (20) having a frequency of alternation that is much higher than the out-of-phase alternating enabling potentials coupled to and controlling operation of said third switching devices, said first, second, and third switching devices comprising of switching transistors; and wherein said gate-triggered conducting devices, said first, second and third switching devices, and said rectifying diodes are manufactured as a monolithic integrated circuit.

Claim 9

An improved power supply circuit according to claim 6 wherein an electroluminescent lamp suitable for use in illuminating the dial of a wristwatch is connected between the corresponding negative terminal electrodes of the first and second gate triggered conducting devices as a capacitive load.

Claim 10

An improved power supply circuit according to claim 6 further including a small trigger gate bias capacitor (26) interconnected between the positive terminal electrode and the control gate of the respective gate triggered conducting devices.

Claim 11

An improved power supply circuit according to claim 6 further including a diode (27) connected between each end of the capactive load and the juncture of the respective trigger gates of the gate triggered conducting devices with the respective first and second switching devices.

Claim 12

An improved power supply circuit according to claim 7 further including a small trigger gate bias capacitor (26) interconnected between the positive terminal electrode and the control gate of the respective gate triggered conducting devices.

Claim 13

An improved power supply circuit according to claim 10 further including a diode (27) connected between each end of the capacitive load and the juncture of the respective trigger gates of the gate controlled triggered devices with respective first and second switching devices.