| 摘要 |
A circuit simulating the function of a diode in the sense that it conducts current in one direction and blocks current in the opposite direction, but which has a low forward voltage drop. A voltage comparator and a three terminal switch are connected so that the intrinsic reverse diode associated with the switch is harnessed to conduct current in the direction in which it is desired to conduct current and to block current in the direction in which it is desired to block current. A voltage comparator controls the control terminal of the three terminal switch to turn on the switch to conduct current from a terminal A to a terminal K when the voltage at terminal A is higher than the voltage at terminal K and to interrupt current from terminal K to terminal A when the voltage at terminal K is higher than the voltage at terminal A. The switch terminal (source or drain) that is typically connected to the higher voltage of two voltage terminals is instead connected to the lower voltage of the two voltage terminals. The switch may be a MOSFET, p- or n-channel, depletion or enhancement. Alternatively, a bipolar transistor may be connected to a voltage comparator to simulate the function of a diode. Detection of a malfunctioning transistor is detected and indicated. Alternate embodiments of voltage comparators are disclosed. The invention further includes a method of conducting, current in one direction and blocking current in a second direction which reduces power losses. |
