Abstract: An impedance analyzer includes a reference signal, a first converter a first coupler, a second converter, a second coupler, a modification circuit, a reference signal detector, and a reflected signal detector. The first coupler couples the reference signal to the first converter. The first converter produces a reference intermediate frequency signal. The second coupler couples a reflected signal to the second converter. The second converter produces a reflected intermediate frequency signal. A reflection coefficient for a device under test is determined by using a reflected value detected by the reflected signal detector and a reference value detected by the reference signal detector. In a first operating mode of the impedance analyzer, the reflected intermediate frequency signal is forwarded directly to the reflected signal detector.

Abstract: Battery jumper cables provide an effective means to connect a charged battery to a discharged battery. However, the electrodes of the batteries must be properly connected for charging to occur and to avoid damage to the batteries. A battery polarity indicator is interposed between a set of battery jumper cables to provide a visual/aural indication of relative battery polarity as well as a safety circuit to prevent electrical connection where polarities are reversed.