Signal multiplier device.

摘要

The signal multiplier device SMD multiplies two signals I1 and I2 applied to its input terminals and generates a digital pulse signal OUT proportional to the result of this multiplicaiton at a terminal OUT. It includes a first pulse density modulator PDM1 converting I1 to a 1-bit word signal C which controls a switch S to connect I2 either directly or via an invertor I to an input of a second pulse density modulator PDM2, depending on the value of C. The device can be included in a device, e.g. an electric energy meter to measure the integral of the product of I1 and I2 or the power of an electric power signal in case of an electric energy meter, in which case I1 is the voltage signal of the electrical power signal, whilst I2 is the current signal or vice-versa. The number of pulses of the digital pulse signal OUT generated during a predetermined time interval is indicative of the power consumption of a user receiver the electric power signal via the meter. <IMAGE>