Active Patent Portfolio

U.S. Pat. No. RE37,130 Signal Conditioning Apparatus

This patent teaches an extremely low cost way to implement the Crystal-Line™ current balanced™ common mode signal isolation technology used by Rockford Fosgate, and International Jensen car stereo amplifiers. Figure 3 shows the actual International Jensen amplifier and how they incorporated the signal isolation technology at a cost of only 15 cents a channel for their unbalanced input preamplifier circuits.

The patent shows how to implement a low cost interface that behaves like a signal isolation transformer but without any compromise in accuracy or fidelity. Like an isolation transformer, the low cost circuits shown are able to isolate the input as well as the output circuit simultaneously. Circuits utilizing the technology can be DC coupled and are not constrained in any practical way with respect to input, output, or any impedance associated with the signal processing part of the circuit.

Important features of the circuit include high common mode rejection ratio without sensitivity to source or destination impedance imbalance and the improvement in dynamic range that is directly proportional to preamplifier gain.

U.S. Pat. No. 6,211,731 Impedance Altering Apparatus

This patent teaches a number of low cost circuits that may be used to implement an analog interface with more that 20 Mega-Ohms of equivalent analog signal common mode isolation. This technology is shown in combination with conventional balanced preamplifier circuits as well as in combination with the Crystal-Line circuit protected by U.S. Pat. No. RE37,130, 5,386,148, and 5,436,593.

U.S. Pat. No. 5,386,148 Signal Conditioning Apparatus

The patent that gave birth to the Crystal-Line circuit technology. Although the patent does not teach a low cost circuit, it does teach the fundamental principles involved. The first Crystal-Line preamplifier product was the preferred embodiment illustrated in the preferred embodiment of the invention. This instance of the Crystal-Line circuit technology is implemented using power supply transformers which are very costly and unlike more recent advances in the circuit technology claimed in later patents, are the source of high frequency conducted RFI interference problems. The claims in this patent encompass all the Crystal-Line circuits and improvements.

U.S. Pat. No. 5,436,593 Signal Conditioning Apparatus

This patent teaches a low cost circuit that implements the technology patented by U.S. Pat. No. 5,386,148. It also includes an improvement which increases common mode rejection ratio by about 3db at very little incremental cost.

U.S. Pat. No. 5,664,022 Noise Gate Control Circuitry for Electronic Systems

This patent teaches a unique hiss noise level sensitive gating control circuit. It also teaches the use of opto-isolators in conjunction with field effect transistors to implement a high power switch applicable to high performance and click less speaker switching.

U.S. Pat. Appl. No. 20080002275 Auxiliary Interface Apparatus

This patent teaches a circuit system for implementing a virtual control for parametric control and selection of auxiliary devices with any factory automotive radio system without the need to reverse engineer any digital protocol.

U.S. Pat. Appl. No. 20060093155 Interface Enhancement Apparatus

This patent teaches a software method for expanding the scope of a numeric control interface. Its primary application is in adapting older CD changer ready car stereo radios with modern MP3 players such as the Apple iPod.