Abstract: The present invention provides processes by which fatigue testing can be carried out by altering the vibrational characteristics of a component, but without physically altering the component itself. In particular the invention provides a method of performing high-cycle fatigue testing on a component, the method including the steps of: attaching one or more masses to the component to alter the stress distribution of the component under vibration; and carrying out high-cycle fatigue testing by exciting the component at a low fundamental frequency of the component. The component can then be tested at a low frequency, which is easier to excite, but fail in a position of the component characteristic of a more complex modeshape.

Abstract: The present invention provides processes by which fatigue testing can be carried out by altering the vibrational characteristics of a component, but without physically altering the component itself. In particular the invention provides a method of performing high-cycle fatigue testing on a component, the method including the steps of: attaching one or more masses to the component to alter the stress distribution of the component under vibration; and carrying out high-cycle fatigue testing by exciting the component at a low fundamental frequency of the component. The component can then be tested at a low frequency, which is easier to excite, but fail in a position of the component characteristic of a more complex modeshape.

Abstract: A programmable gain amplifier having three separately programmable amplifiers. A programmable transconductance amplifier is followed by a programmable transimpedance amplifier, then a programmable switched capacitor amplifier. In one embodiment, this programmable gain amplifier is implemented in an analog front-end (AFE) circuit. One AFE embodiment provides a coarse pre-gain offset a black reference level sampler, and a fine post-gain offset in the programmable switched capacitor amplifier. In one embodiment, an ADC reference is sampled, and is subtracted directly from the video signal in the switched capacitor amplifier so that the zero level of the video signal is made to correspond to the zero level of the ADC.