The composition of pulsed watt-hour meter and the working principle of pulse device

The Pulse watt-hour meter provides the functions of collecting power, load monitoring, data transmission and so on for comprehensive automatic substation and remote automatic monitoring.
The Pulse watt-hour meter is mainly composed of two parts, the electric energy measurement component and the pulse device. The electric energy measurement part is the inductive watt-hour meter, and the pulse device includes two parts: Pulse sampling signal generation circuit and pulse output circuit.
Photoelectric sampling is a kind of pulse sampling method which is more common at present. The light source is divided into modulated light and non-high light, non-modulated light is emitted by the light emitting diode infrared, the receiving part is a photosensitive transistor or a photodiode. As shown in the accompanying drawings. This is a transmission type photoelectric sampling pulse signal generator circuit.
When the fan blades fixed on the electric energy meter hinge cover the Light emitting element (light emitting diode) with the disc, the light element (photosensitive transistor or photodiode) is cut off, and when the vane is rotated, the infrared light emitted by the light emitting element is transmitted through the gap between the vane and the vane, so that the optical element receives the conduction. As a result, a pulse signal is produced that is proportional to the number of disc turns.
ac100v AC power supply by T1 Buck, U1 rectification, C2 filtering, and then by the three-terminal regulator IC1 to be regulated. When the disk of the watt-hour meter rotates between the light-emitting diode VD1 and the photosensitive transistor V1, or the fan blades fixed on the electric energy meter hinge rotate with the disc, the photosensitive transistor alternately is excited on the conduction or cutoff. So that the sampling signal through the amplification circuit IC2 input to the double single-stable multi-harmonic oscillator IC3, through the signal shaping, produce a rectangular output signal (the pulse amplitude is generally selected as 12V, 24V, the allowable deviation ±5%, pulse width is generally set to 10ms, Ms S, MS or MS, pulse width allowable error ±20% ）。 The output signal is amplified with the amplifier, and finally the isolated output is IC4 by the photoelectric coupler.

The composition of pulsed watt-hour meter and the working principle of pulse device