An electronic device (10, 20, 70, 80), comprising: a coil (101, 201, 701, 801), a chip (102, 702, 803, 202) with a contact-less function, a rectifier (103, 203, 703) and a switcher (104, 204, 802), wherein the switcher (104, 204, 802) is connected between the coil (101, 201, 701, 801) and the chip (102, 702, 803, 202), a first output terminal of the coil (101, 201, 701, 801) is electrically connected to a first input terminal of the rectifier (103, 203, 703) and is electrically connected to a second input terminal of the chip (102, 702, 803, 202) via the switcher (104, 204, 802), a second output terminal of the coil (101, 201, 701, 801) is electrically connected to a second input terminal of the rectifier (103, 203, 703) and is electrically connected to a second terminal of the switcher (104, 204, 802) wherein the coil (101, 201, 701, 801) is configured to sense a field and to output an alternating current signal via the first output terminal; the rectifier (103, 203, 703) is grounded and is configured to receive the AC signal input by the coil (101, 201, 701, 801) via the first input terminal, and to output electric power via an output terminal of the rectifier (103, 203, 703) to the switcher; and the switcher (104, 204, 802) is configured to connect the coil (101, 201, 701, 801) to the chip (102, 702, 803, 202) under control of an input operating voltage, and to control connection and disconnection of the coil (101, 201, 701, 801) and the chip (102, 702, 803, 202) according to a control signal when the control signal is received, the input operating voltage being set by default; characterized in that the switcher (104, 204, 802) comprises: an AC input terminal, a third output terminal, a control module, a first ON/OFF module and a second ON/OFF module, wherein the first ON/OFF module is provided to couple a first end of the AC input terminal and a first end of the third output terminal, and is configured to be controlled to transfer to an ON state or an OFF state, wherein a first path is switched on and a second path is switched off when the first ON/OFF module is in the ON state, the first path is switched off and the second path is switched on when the first ON/OFF module is in the OFF state, the first path and the second path are in opposite flow directions, and the first path is a path from the first end of the AC input terminal to the first end of the third output terminal or a path from the first end of the third output terminal to the first end of the AC input terminal; the second ON/OFF module is provided to couple a second end of the AC input terminal and a second end of the third output terminal, and is configured to be controlled to transfer to an ON state or an OFF state, wherein a third path is switched on and a fourth path is switched off when the second ON/OFF module is in the ON state, the third path is switched off and the fourth path is switched on when the second ON/OFF module is in the OFF state, the third path and the fourth path are in opposite flow directions, and the third path is a path from the second end of the AC input terminal to the second end of the third output terminal or a path from the second end of the third output terminal to the second end of the AC input terminal; and the control module is provided to couple the input operating voltage of the switcher (104, 204, 802) and a common ground, and is configured to be controlled to transfer to an ON state or an OFF state, wherein the control module is configured to control the first ON/OFF module and the second ON/OFF module to transfer to the OFF state when the control module is in the ON state, and to control one of the first ON/OFF module and the second ON/OFF module to transfer to the ON state and the other one of the first ON-OFF module and the second ON-OFF module to transfer to the OFF state by cooperating with the AC input terminal when the control module is in the OFF state.