A detection circuit for open, close and suspension states of a high and low level effective switch in a vehicle. The circuit includes an optocoupler circuit module, a low-level active path module, a high-level active path module, a filtering and debouncing module, a transient suppression module, and a wiring terminal. The optocoupler circuit module is connected to the low-level active path module, the high-level active path module and the low-level active path module are connected in parallel to the filtering and debouncing module, and the filtering and debouncing module is connected to the transient suppression module, and then connected to the external high-level active switch or low-level active switch through the wiring terminal. Whether it is a high-level active switch or a low-level active switch, the detection circuit can distinguish whether the switch is in the closed or suspended state, and the strong and weak voltages are isolated.

A rapid shutdown device capable of driving two MOSFETs connected in series through single drive signal, which includes a switch S1, a switch S2, a control IC and a drive circuit. The PV+ terminal of the photovoltaic module is connected to an output terminal OUT+ through the switch S1 and the switch S2 connected in series in sequence. The PV− terminal of the photovoltaic module is connected to an output terminal OUT−. The control IC, the switch S1 and the switch S2 are connected with the drive circuit respectively, and the two signal terminals of the control IC control the on-off of switch S1 and switch S2 through the drive circuit. The invention adopts two switches connected in series for on-off operation, greatly improving the shutoff reliability and safety of the photovoltaic power generation system.

A standby power system for a flyback converter is disclosed. The flyback converter includes a primary-side, a secondary-side, an output terminal at the secondary-side, and a secondary-side controller, where the output terminal is configured to electrically connect to a load. The standby power system comprises a comparator at the secondary-side, an opto-coupler in signal communication with the primary-side, the secondary-side, and the comparator, and a cable detach detector (or load detector). The cable detach detector is configured to determine whether a device is electrically connected to the flyback converter through a charging cable and to set the flyback converter into a standby mode if the deice is disconnected from the charging cable.

A device including an optoelectric circuit that is configured to provide galvanic isolation between a first circuit and a second circuit is disclosed. The optoelectric circuit includes at least one non-inverting buffer and a metal semiconductor diode. The at least one non-inverting buffer is positioned between a collector of a phototransistor and an anode of a light emitting diode. The metal semiconductor diode is positioned between the collector of the phototransistor and the at least one non-inverting buffer.

The present invention introduces an arrangement for enhancing the performance of an electronic circuit comprising a phototransistor (Q). Either a common-collector or a common-emitter connected phototransistor (Q) has a main resistor (R.sub.L), and at least one external bias resistors (R.sub.L2, R.sub.L3, R.sub.L4), each in parallel to one another. The microcontroller may directly control the voltage outputs or act via respective switches (S1, S2) regarding each respective resistor. When the electronic circuit with the phototransistor (Q) is switched on, at least one of the external bias resistors (R.sub.L2, R.sub.L3, R.sub.L4) are switched on. The voltage output rise time is short, and when the bias has been set, the external bias resistor(s) are disconnected functionally. This means that during the actual measurement with the electric circuit, only the main resistor (R.sub.L) is used in the connection.

An arrangement (1) with an electronically commutated motor has an interface (10) for inputting analog setpoint signals (S) for the motor. The motor is powered, during operation, by an AC network via an electronic commutation system (20). The interface (10) is galvanically isolated from the electronic commutation system (20) by a galvanic isolation (30). Furthermore, for the transmission of an analog setpoint signal (S), a bitstream signal production device (2) is provided on the galvanically isolated interface side. Also provided is a transmission device (3), for transmitting the produced bitstream, as well as a signal-processing device (4). They are on the non-galvanically isolated side for the signal evaluation of the bitstream.

A method for adjusting an optical switch keyboard and an optical switch keyboard using the adjusting method are provided. The optical switch keyboard has a number of key units. The method includes the following steps. A scan signal is applied to one of a number of scan lines by a control unit at a first scan time point. A light is emitted by a light source according to the scan signal. A light emitted by the light source is detected by a detecting element to generate a detecting electric signal. The detecting electric signal is read by the control unit to obtain a first read signal voltage. When the first read signal voltage is outside the voltage range of the pressed state of the key unit, the period of the scan signal is increased by a first predetermined amount by the control unit to obtain an adjusted scan signal.

In one embodiment, an RF power amplifier includes a first transistor and a second transistor in parallel, wherein a gate of the first transistor and a gate of the second transistor are configured to be driven by an RF source. A third transistor comprising a drain is operably coupled to both a source of the first transistor and a source of the second transistor. A control circuit is operably coupled to a gate of the third transistor and configured to alter a gate-to-source voltage of the third transistor, thereby altering a drain current of each of the first transistor and the second transistor, thereby altering an output power of the RF power amplifier.

A rapid shutdown device capable of driving two MOSFETs connected in series through single drive signal, which includes a switch S1, a switch S2, a control IC and a drive circuit. The PV+ terminal of the photovoltaic module is connected to an output terminal OUT+ through the switch S1 and the switch S2 connected in series in sequence. The PV− terminal of the photovoltaic module is connected to an output terminal OUT−. The control IC, the switch S1 and the switch S2 are connected with the drive circuit respectively, and the two signal terminals of the control IC control the on-off of switch S1 and switch S2 through the drive circuit. The invention adopts two switches connected in series for on-off operation, greatly improving the shutoff reliability and safety of the photovoltaic power generation system.

In one embodiment, an impedance matching network includes an electronically variable reactance element (EVRE) comprising discrete reactance elements and corresponding switches. The switches are configured to switch in and out the discrete reactance elements to alter a total reactance provided by the EVRE. A monitoring circuit is operably coupled to the EVRE. For each discrete reactance element, the monitoring circuit monitors a value related to the discrete reactance element or its corresponding switch. Upon determining the monitored value exceeds a predetermined amount, the monitoring circuit the discrete reactance element of the EVRE from switching in or out.