Abstract: A protection circuit for electronic ballasts which use charge pump power factor correction includes a switch with an overvoltage sensor, a resistor and a diode. In the event of a fault condition, the switch disables the charge pump power factor correction, while the resistor and diode prevent the switch dissipating unduly large amounts of energy.

Abstract: A self-dimming electronic ballast for a gas discharge lamp includes a converter having an unregulated boost circuit coupled to a variable frequency inverter having a series resonant, parallel loaded output. The inverter includes a variable frequency driver circuit having a timing circuit for determining the frequency of the driver. A transistor in the timing circuit operates as an inverting amplifer and is controlled by a signal proportional to the voltage of the AC line. The frequency of the inverter increases with decreasing voltage on the AC line. The ballast can be on the same circuit as incandescent lamps and powered by a triac or variac dimmer for dimming both the incandescent and gas discharge lamps.

Abstract: A circuit for powering a gas discharge lamp from a source of a first frequency AC power has a a first rectifier for converting the first frequency AC power into a first DC power, a capacitor and driver for converting the DC power to a second frequency AC power. A second rectifier is used to increase the power factor for the circuit. A control is provided to disable the second rectifier if the lamp is removed from the circuit.

Abstract: A circuit (100) for powering fluorescent lamps (102, 104 & 106) includes a switch (50) having "open" and "closed" positions. When power is initially applied to the circuit, the lamps are powered at full power to enable them to "strike". After a short period, the power is reduced to the lamp. A control circuit (300) thereafter senses if the switch has been "toggled". If toggled, the power to the lamps is increased, and the lamps brighten. The circuit uses a conventional two-position switch and conventional wiring and avoids the need for additional switches and additional wiring.

Abstract: A ballast circuit (100) includes a ground fault detector (200). The ballast circuit is arranged for coupling to a power source (101) and a load (135, 137), the power source characterized by a source frequency, the ballast circuit including an electromagnetic interference ("EMI") filter (110) which includes a ground terminal (145). The ground fault detector (200) determines when the load is coupled to a ground fault (141) by detecting the presence of a high-frequency current at the ground terminal, the high-frequency current characterized by a frequency that is substantially greater than the source frequency. When the high-frequency current is detected, the ground fault detector provides an output signal (150) which may be used to disconnect the load from the ballast circuit.

Abstract: A silicon on insulator of integrated circuit comprising a plurality of components typically adopted for high voltage application having a semiconductor substrate of a first conductivity type, an insulating layer provided on the substrate, a semiconductor layer provided on the insulating layer, a number of laterally separated circuit elements forming parts of a number of subcircuits provided in the semiconductor layer, a diffusion layer of a second conductivity type opposite to that of the first conductivity type provided in the substrate and laterally separated from all the other circuit elements and means for holding the diffusion layer at a voltage at least equal to that of the highest potential of any of the subcircuits present in the integrated device.

Abstract: To switch a first gated diode switch (GDSL1) to the "OFF" state requires a voltage applied to the gate which is more positive than that of the anode or cathode and a sourcing of current into the gate of substantially the same order of magnitude as flows between the anode and cathode of the first switch. Control circuitry, which uses a second gated diode switch (GDSC) coupled by the cathode to the gate of the first switch (GDSL1), is used to control the state of the first switch (GDSL1). The control circuitry also comprises a first branch circuit coupled to the anode of the GDSC and to a first potential source V1 and a second branch circuit coupled to the anode of GDSC and to a second potential source V2 which is of a lower potential than V1. The second branch circuit has a high voltage and high current capability switch in series between V2 and the anode of GDSC. The first branch circuit has a high voltage but modest current handling switch in series between V1 and the anode of GDSC.

Abstract: A high voltage solid-state switch, which provides bidirectional blocking, consists of a first p- type semiconductor body separated from a support member (semiconductor substrate) by a dielectric layer with a p+ type anode region located at one end of the semiconductor body, an n+ type cathode region located at the other end, and an n+ type gate region located between the anode and cathode regions. A second p type region of higher impurity concentration than the semiconductor body surrounds the cathode region. Separate low resistance electrical contacts are made to the anode, cathode, and gate regions and to the substrate. The switch is capable of switching from an "ON" and conducting state to an "OFF" (blocking) state by adjusting the potential of the gate region and without having to adjust the potential of the anode or cathode regions.

Abstract: A high voltage solid-state switch, which provides bidirectional blocking, consists of a first p- type semiconductor body having a major surface and being separated from a support member (semiconductor substrate) by a dielectric layer with a p+ type anode region located at one end of the semiconductor body and having a portion which is common with the major surface, an n+ type cathode region located at the other end and having a portion which is common with the major surface, and an n+ type gate region having a portion which is common with the major surface and in one embodiment being located essentially between the anode and cathode regions and in another embodiment being located other than directly between the anode and cathode regions. A second p type region of higher impurity concentration than the semiconductor body surrounds the cathode region. An n+ type semiconductor layer is sandwiched between the semiconductor body and the dielectric layer.

Abstract: A high voltage solid-state switch, which provides bidirectional blocking, consists of a first p- type semiconductor body separated from a support member (semiconductor substrate) by a dielectric layer with a p+ type anode region located at one end of the semiconductor body, an n+ type cathode region located at the other end. An n+ type gate region exists in a portion of the semiconductor body other than the portion which directly separates the anode and cathode regions. A second p type region of higher impurity concentration than the semiconductor body surrounds the cathode region. Separate low resistance electrical contacts are made to the anode, cathode, and gate regions and to the substrate. The switch is capable of switching from an "ON" and conducting state to an "OFF" (blocking) state by adjusting the potential of the gate region and without having to adjust the potential of the anode or cathode regions.

Abstract: A high voltage solid-state switch, which provides bidirectional blocking, consists of a first n type semiconductor body separated from a support member (semiconductor substrate) by a dielectric layer with a p+ type anode region located at one end of the semiconductor body, an n+ type cathode region located at the other end, and an n+ type gate region located between the anode and cathode regions. A second p type region of lower impurity concentration than the anode region surrounds the cathode region so as to separate it from the bulk portion of the semiconductor body. Separate low resistance electrical contacts are made to the anode, cathode, and gate regions and to the substrate. The switch is capable of switching from an "ON" and conducting state to an "OFF" (blocking) state by adjusting the potential of the gate region and without having to adjust the potential of the anode or cathode regions.

Abstract: A high voltage solid-state switch, which provides bidirectional blocking, consists of a first p- type semiconductor body on an n type semiconductor substrate. A p+ type anode region and an n+ type cathode region exist in portions of the semiconductor body. A second p type region of higher impurity concentration than the semiconductor body surrounds the cathode region. The anode region and second p type region are separated from each other by a portion of the semiconductor body. The semiconductor substrate, which acts as a gate, has an electrode connected thereto. Separate electrodes are connected to the anode and cathode regions.

Abstract: An integrated circuit switch having a pair of serially connected SCRs with diodes connecting the gates of the SCRs to an independent bias source such that the second SCR is gated on first to enable the gating of the first SCR in the series connection.

Abstract: An integrated circuit switch having a pair of serially connected SCRs with diodes connecting the gates of the SCRs to independent biasing and switching sources such that the second SCR is gated on first to enable the gating of the first SCR in the series connection. A switch controls the state of the second SCR.

Abstract: A gated diode switch (GDS1, GDS3, GDS4, GDS10) requires a voltage applied to the gate which is more positive than that of the anode and cathode in order to break current flow between the anode and cathode. In addition, a current of at least the same order of magnitude as flows between anode and cathode must flow into the gate of the switch to break current flow. The use of a second gated diode switch (GDS2, GDS20) coupled by the cathode (28, 280) to the gate of a gated diode switch (GDS1, GDS3, GDS4, GDS10) which is to be controlled provides a high voltage and current capability means for cutting off (interrupting) or inhibiting current flow through the gated diode switch (GDS1, GDS3, GDS4, GDS10). The state of a gated diode switch (GDS1, GDS3, GDS4, GDS10) is thus controlled by a second gated diode switch (GDS2, GDS20).

Abstract: A phase-to-voltage converter having a capacitor whose terminals are alternately charged by an AC voltage supply while the other terminal is fixed at a reference potential. The charging of the terminals is terminated by a switch which monitors the reversal of the current through the inductive load.

Abstract: To switch a first gated diode switch (GDS1) to the "OFF" state requires a voltage applied to the gate which is more positive than that of the anode or cathode and a sourcing of current into the gate of substantially the same order of magnitude as flows between the anode and cathode of the first switch. Control circuitry, which uses a second gated diode switch (GDSC) coupled by the cathode to the gate of the first switch (GDS1), is used to control the state of the first switch (GDS1). The control circuitry comprises a first branch circuit coupled to the gate of GDSC and to a first potential source +V1 and a second branch circuit coupled to the anode of GDSC and to a second potential source V2. The first branch circuit is connected to the gate of the second switch (GDSC) and controls the state thereof. The second branch circuit helps switch the first switch to the OFF state by providing a single current pulse or a plurality of current pulses into the gate of the first switch.

Abstract: To switch a first gated diode switch (GDS1) to the "OFF" state requires a voltage applied to the gate which is more positive than that of the anode or cathode and a sourcing of current into the gate of substantially the same order of magnitude as flows between the anode and cathode of the first switch. Control circuitry, which uses a second gated diode switch (GDSC) coupled by the cathode to the gate of the first switch (GDS1), is used to control the state of the first switch (GDS1). The control circuitry comprises a first branch circuit coupled to the gate of GDSC and to a first potential source +V1, a second branch circuit coupled to the anode of GDSC and to a second potential source +V2, and a third branch circuit coupled to the anode of GDSC and to a third potential source +V3. The first branch circuit is connected to the gate of the second switch (GDSC) and controls the state thereof.

Abstract: A solid-state protector circuit utilizes the combination of two zener diodes (Z1, Z2), a resistor (R1), a capacitor (C1), and a gated diode switch (GDS) to facilitate the rapid discharge of high voltage transients.

Abstract: A high voltage solid-state switch uses a dielectrically isolated lightly doped p- type semiconductor body with a heavily doped p+ type anode region, a heavily doped n+ type gate region, a moderately doped p type shield region, and a heavily doped n+ type cathode region. The shield region surrounds the cathode region. Separate electrodes contact the anode, gate, shield, and cathode regions. The gate and cathode regions also act as the collector-emitter output circuitry of an n-p-n transistor with the shield region acting as the base. With the shield (base) region forward-biased with respect to the cathode or gate regions, the n-p-n transistor is biased on and the collector and emitter are rapidly pulled close to each other in potential. With proper operating potentials applied to the anode and cathode regions, the switch rapidly assumes an "ON" state when the potential of the shield (base) region is set to a level which biases the n-p-n transistor ON.