Galaxy Power, Inc.

Digital Equipment Corporation

Compaq Computer Corporation, Inc.

Compag Computer Corporation

William W Ng

Bernhard Schroter

Gerald Miller

Andrew Ferencz

Gregory A Zvonar

Fu-Sheng Tsai

A transformer has a primary winding made from a first conducting trace formed on a first multilayer printed circuit board, and a secondary winding made from a second conducting trace formed on a second multilayer printed circuit board. The primary winding is magnetically coupled to the secondary winding. The windings are etched as traces in copper layers of the PC boards as spirals. The spiral of one copper layer is connected to the spiral of a different copper layer by a via, or vias, formed through the insulating layer of the PC board. The vias are drilled, cleaned, and plated with conducting material, for example copper. By using multiple layers, and by connecting spiral windings of each layer to the windings of the next layer by use of vias, any number of turns can be built into a primary winding, or into a secondary winding.

Simplified transformer design for a switching power supply

The invention replaces a snubber resistor with a two diodes and a load. The electric charge stored in the snubber capacitor on each cycle of the switch is then caused by a first diode to flow through the load, rather than to flow through a snubber resistor. A second diode provides a charging path for the snubber capacitor. The load uses the electric power which would be wasted in the snubber resistor.

Utilizing charge stored in a snubber capacitator in a switching circuit

An inductor for a computer power supply module is provided. The inductor includes a one-piece, single turn winding formed of a material for conducting heat and electrical current. The material having at least about five times the amount of electrically conductive material necessary for conducting electrical current.

Thermally conducting inductors

A power supply module for a computer is provided. The module includes a multilayer pc board, heat generating electrical components disposed on the board, logic elements disposed on the board and a heat sink. The module also includes thermal conducting structure disposed coupled to the pc board and thermally coupled to the heat sink and to the heat generating electrical components for transferring heat from the heat generating electrical components to the heat sink.

Single board power supply with thermal conductors

A technique involves broadcasting a pulse signal to synchronize oscillating signals used by multiple power supplies to provide output voltages. The technique involves charging and discharging respective capacitors of the multiple power supplies at respective rates to provide the oscillating signals. Each of the respective capacitors is charged until a voltage across that capacitor reaches a respective upper threshold and subsequently discharged until the voltage across that capacitor reaches a respective lower threshold. The technique further involves broadcasting, from at least two of the power supplies, a pulse signal to a synchronization connection coupled to each of the respective capacitors to modify the respective rates for charging and discharging the respective capacitors based on the pulse signal such that oscillating signals become synchronized.

Methods and apparatus for synchronizing a plurality of power supplies

A transformer is provided that consists of a primary winding, a secondary winding and a magnetic core. The primary winding is wound directly around the magnetic core, thereby removing the need for a bobbin. By removing the need for the bobbin, the transformer has a large window utilization factor, and associated low profile. As a result, the transformer has a high power to form factor ratio. A method for making the transformer includes the steps of joining two halves of the core before winding the primary winding. Because the half-cores are joined prior to the wrapping of the primary winding, the core provides bobbin functionality. In addition, a header plate is provided for coupling a plurality of leads of a transformer to sources on an integrated circuit board, where the transformer consists of a magnetic core, a primary winding and a secondary winding. The header plate engages the magnetic core, providing a termination path for the wire of the secondary winding. In addition, the header plate assists in providing electrical insulation for the core while providing a mechanism for ensuring that electrical safety constraints between the primary winding and the core are satisfied.

Header plate for a low profile surface mount transformer

Low profile surface mount transformer

A technique for controlling a power supply involves receiving a programming signal that indicates a power supply output voltage limit, activating the power supply such that the power supply provides a power supply output voltage according to a power supply threshold voltage, generating a tracking signal that tracks the programming signal, and generating a compare signal according to the tracking signal and an actual value of the power supply output voltage. The technique further involves comparing the compare signal to a protection threshold voltage, maintaining activation of the power supply when the compare signal is less than the protection threshold voltage, and deactivating the power supply when the compare signal is greater than the protection threshold voltage. The protection threshold voltage is independent of the power supply threshold voltage. In particular, a power supply threshold reference source provides the power supply threshold voltage, a protection threshold reference source, which is independent of the power supply threshold reference source, provides the protection threshold voltage.

Methods and apparatus for controlling a power supply with improved

Transformers (T1, T2), switches (M1) and (M2), rectifiers (DR1, DR2, DR3, DR4) and low-pass filter (LF, CF) form a basic power train circuit (12). Auxiliary switches (A1, A2), diodes (DS1, DS2) and capacitors (CS1, CS2) form active clamp circuit (10). The capacitances for (CS1, CS2) are chosen large enough such that the voltages (vCS1, vCS2) across the capacitors are essentially constant during several switching cycles. Switches (M1) and (A1) are driven by the signal (V.sub.G1), while switches (M2) and (A2) are driven by (V.sub.G2). When (M1) is turned OFF, the energies stored in the magnetizing and leakage inductances in (T1) will resonate with the output capacitance of (M1) first. When the voltage (V.sub.M1) across (M1) exceeds the voltage (V.sub.CS1) across (CS1), (DS1) conducts and (V.sub.M1) is clamped at (V.sub. CS1), which has a steady-state value of slightly less than two times the input voltage (E). During this interval, the capacitor (CS1) is charged by the leakage inductor current (i.sub.LK1). When (i.sub.LK1) reduces to zero, (DS1) stops conducting, and (V.sub.M1) decreases to the level of (E). When (M2) is triggered, (A1) is also triggered. Diodes (DS1) and (DS2) are both reverse-biased. The energy in capacitor (CS1) is discharged through (A2) back to (E). Meanwhile, transformer (T1) is being reset. When (M2) is turned OFF, (A2) is also turned OFF. Voltage (V.sub.M1) decreases to (E), and a similar process occurs for the following half switching cycle, with the roles of (M1, A1, DS1, CS1, T1) and (M2, A2, DS2, CS2, T2) interchanged, respectively.

Growing community of inventors

Leominster, MA, United States of America

William W Ng