Abstract: Disclosed herein is a dimmer switch having a broad range of control with a relatively simple circuit having a number of safety features. The circuit employs a triac and diac to selectively conduct an AC power wave. A variable phase shift network having an improved range of control governs the firing angle of the diac. The variable phase shift network includes a first and second series R-C circuits coupled by a bridge resistor.

Abstract: A card authentication system. In one embodiment, the invention relates to a method for authenticating a data card having an intrinsic magnetic characteristic and recorded data on the data card, the method including reading information from the data card, the data card information including the intrinsic magnetic characteristic and the recorded data on the data card, encrypting the data card information, sending the encrypted data card information, receiving the encrypted data card information, decrypting a portion of the encrypted data card information, the portion including the intrinsic magnetic characteristic, generating a score indicative of a degree of correlation between the intrinsic magnetic characteristic of the data card information and a stored value, and determining an authenticity of the data card based at least in part on the score.

Abstract: A system for verifying the authenticity of data contained in a magnetic medium using the remanent noise characteristics of the magnetic medium. In one embodiment, the invention includes a sensing unit configured to generate a signal indicative of the magnetic field of the magnetic medium, an analog-to-digital converter (ADC) in communication with the sensing unit and configured to digitize the analog signal, a filter in communication with the ADC configured to enhance the component of the signal associated with the remanent noise characteristic, a data extraction unit, in communication with the ADC and the filter configured to measure at least bit duration and peak location and an authentication extraction unit, in communication with the filter and the data extraction unit configured to extract a set of scaled samples from the output of the filter representative of the remanent noise characteristic.

Abstract: Disclosed herein is a dimmer switch having a broad range of control with a relatively simple circuit having a number of safety features. The circuit employs a triac and diac to selectively conduct an AC power wave. A variable phase shift network having an improved range of control governs the firing angle of the diac. The variable phase shift network includes a first and second series R-C circuits coupled by a bridge resistor.

Abstract: A card authentication system. In one embodiment, the invention relates to a method for authenticating a data card having an intrinsic magnetic characteristic and recorded data on the data card, the method including reading information from the data card, the data card information including the intrinsic magnetic characteristic and the recorded data on the data card, encrypting the data card information, sending the encrypted data card information, receiving the encrypted data card information, decrypting a portion of the encrypted data card information, the portion including the intrinsic magnetic characteristic, generating a score indicative of a degree of correlation between the intrinsic magnetic characteristic of the data card information and a stored value, and determining an authenticity of the data card based at least in part on the score.

Abstract: A system for verifying the authenticity of data contained in a magnetic medium using the remanent noise characteristics of the magnetic medium. In one embodiment, the invention includes a sensing unit configured to generate a signal indicative of the sensed magnetic field and an amplifier. The amplifier is in communication with the sensing unit, is configured to amplify signals having amplitudes less than a threshold by at least a first factor and configured to amplify signals having amplitudes greater than the threshold by at most a second factor. The first factor is greater than the second factor.

Abstract: A system for verifying the authenticity of data contained in a magnetic medium using the remanent noise characteristics of the magnetic medium. One embodiment of the invention includes an over-sampled modulator and at least one channel in communication with an output of the over-sampled modulator. The at least one channel is configured to filter the output of the over-sampled modulator and the at least one channel is configured to vary the bandwidth of the filter applied to the output of the over-sampled modulator in response to variations in the bandwidth of the signal generated by the sensing unit.