| 摘要 |
PURPOSE:To increase the processing speed of a circuit and to realize the application of a low-cost IC, by correcting the offset output at each prescribed time or each end of a prescribed number of times of use when the electric power is counted from the digital voltage or digital current of a circuit to be measured. CONSTITUTION:The voltage and current of a circuit to be measured are applied to the input terminals 1 and 2, and the terminals 1 and 2 are connected to the sample holding circuits 6 and 7 via the electronic switches 3 and 4 which are controlled by the output of an output circuit 5. A CPU10 feeds the outputs of the A/D converting circuits 8 and 9 to a storage device 12, and a prescribed program is set to an ROM13. The difference is obtained between the outputs subjected to the A/D conversions 8 and 9 and the offset output obtained in the non- signal mode. These outputs are then delivered to an output circuit 14 after multiplication, addition and accumulation. This offset output is stored, and the working frequency is set at a prescribed level. The offset output is corrected with each end of a prescribed working frequency. Thus the arithmetic speed is increased for the CPU, and a low-cost IC can be applied for a circuit. |
