| 摘要 |
<p>A circuit for sensing the current delivered to a load, or multiple loads, such presented by a polyphase DC motor, without significantly dissipating the energy delivered to the load, has a predriver circuit (30,31,32) and a power delivery circuit (40,41,42) for each load. The predriver circuit is connected in a series path between a voltage source and a control element of the power delivery circuit, and the power delivery circuit is connected between a connection node and a respective one of the loads. A sensing element (49) is connected in a series path between the source of voltage and the power delivery circuit connection node. In a preferred embodiment, the sensing element is a resistor, the predriver circuit is a PNP transistor, and the power delivery circuit is an NPN transistor. The PNP and NPN transistors are connected to form a pseudo-Darlington transistor pair, with the collectors of the NPN transistors interconnected to enable a single sense resistor to be used to sense the current in each of the loads. <IMAGE></p> |
