Buried object locator systems including transmitters and associated buried object locators using phase-synchronized signals are disclosed. A transmitter may generate output current signals that are phase-synchronized with a corresponding locator for improved utility locating.

A power supply system includes a power supplier circuit and a power receiver circuit. The power supplier circuit supplies a power via a communication interface compatible with a first communication interface specification or a second communication interface specification. The first communication interface specification includes a delay threshold. After the power supplier circuit is coupled to the power receiver circuit, the power supplier circuit supplies the power after a first delay period. The power receiver circuit confirms whether the power supplier circuit is coupled to the power receiver circuit via a coupling confirmation step according to the first communication interface specification. The power receiver circuit confirms whether the power supplier circuit is compatible with the first communication interface specification or the second communication interface specification according to whether the first delay period is greater than the delay threshold.

A power supply system includes a power supplier circuit and a power receiver circuit. The power supplier circuit supplies a power via a communication interface compatible with a first communication interface specification or a second communication interface specification. The first communication interface specification includes a delay threshold. After the power supplier circuit is coupled to the power receiver circuit, the power supplier circuit supplies the power after a first delay period. The power receiver circuit confirms whether the power supplier circuit is coupled to the power receiver circuit via a coupling confirmation step according to the first communication interface specification. The power receiver circuit confirms whether the power supplier circuit is compatible with the first communication interface specification or the second communication interface specification according to whether the first delay period is greater than the delay threshold.

A plurality of electrochemical corrosion protection systems (30) for underground buried structure installed geographically dispersed are utilized so as to predict an earthquake. Changes in amounts of current flowing through closed loop electric circuits (W) for electrochemical corrosion protection in the electrochemical corrosion protection systems (30) are detected and an earthquake is predicted based on the detected changes in the amounts of current.

A metal detector for buried and abandoned chemical weapons is provided, comprising: a transmitting circuit to transmit a detection signal; a frequency selection unit electrically connected to the transmitting circuit and configured to regulate a frequency of the detection signal; a receiving circuit to receive a reflected signal returned from the substance detected; an analog-digital conversion unit electrically connected to the receiving circuit and configured to convert the reflected signal into a digital signal; and a control unit electrically connected to the analog-digital conversion unit. In the present disclosure, the frequency of the detection signal can be regulated by changing a current frequency of the transmitting circuit, so that several forms of iron compound can be detected, thereby increasing the detection accuracy of the ACWs.

A metal detector for buried and abandoned chemical weapons is provided, comprising: a transmitting circuit to transmit a detection signal; a frequency selection unit electrically connected to the transmitting circuit and configured to regulate a frequency of the detection signal; a receiving circuit to receive a reflected signal returned from the substance detected; an analog-digital conversion unit electrically connected to the receiving circuit and configured to convert the reflected signal into a digital signal; and a control unit electrically connected to the analog-digital conversion unit. In the present disclosure, the frequency of the detection signal can be regulated by changing a current frequency of the transmitting circuit, so that several forms of iron compound can be detected, thereby increasing the detection accuracy of the ACWs.

An apparatus includes a first and a second earbud and a case. The case is configured to provide an enclosure for the first and the second earbud and detect an insertion of either of the first earbud or the second earbud in the enclosure by using detection of a current provided to at least one of the first earbud and the second earbud.

An apparatus includes a first and a second earbud and a case. The case is configured to provide an enclosure for the first and the second earbud and detect an insertion of either of the first earbud or the second earbud in the enclosure by using detection of a current provided to at least one of the first earbud and the second earbud.

A power supply system includes a power supplier circuit and a power receiver circuit. The power supplier circuit supplies a power via a communication interface compatible with a first communication interface specification or a second communication interface specification. The first communication interface specification includes a delay threshold. After the power supplier circuit is coupled to the power receiver circuit, the power supplier circuit supplies the power after a first delay period. The power receiver circuit confirms whether the power supplier circuit is coupled to the power receiver circuit via a coupling confirmation step according to the first communication interface specification. The power receiver circuit confirms whether the power supplier circuit is compatible with the first communication interface specification or the second communication interface specification according to whether the first delay period is greater than the delay threshold.

A power supply system includes a power supplier circuit and a power receiver circuit. The power supplier circuit supplies a power via a communication interface compatible with a first communication interface specification or a second communication interface specification. The first communication interface specification includes a delay threshold. After the power supplier circuit is coupled to the power receiver circuit, the power supplier circuit supplies the power after a first delay period. The power receiver circuit confirms whether the power supplier circuit is coupled to the power receiver circuit via a coupling confirmation step according to the first communication interface specification. The power receiver circuit confirms whether the power supplier circuit is compatible with the first communication interface specification or the second communication interface specification according to whether the first delay period is greater than the delay threshold.