1、 Overview

DDSY1791 typeRemote single-phase prepaid energy meterUsing dedicated integrated circuit design and fully automated surface mount (SMT) production process manufacturing. The circuit design and component selection of the electric energy meter are based on a large environmental tolerance, which can ensure long-term stable operation of the whole machine, high precision, high overload, low power consumption, and high reliability performance. Adopting advanced intelligent IC card technology that meets international standards to achieve prepaid payment, with built-in magnetic holding relay. By controlling the relay to control the on and off of the load, the function of urging users to buy electricity before using it can be achieved.

Main features: Application of computer management, purchasing electricity first and then using it; The maximum operating power can be limited within the rated current range (limited by the power supply department); SMS notification or automatic power outage alert for users to purchase electricity; When the battery level is zero, the power will automatically trip and cut off; And it has certain anti-theft software design, etc.

The product meets all technical requirements of GB/T17215.321-2008 "Level 1 and Level 2 Static AC Active Energy Meters" and GB/T 18460.3-2001 "IC Card Prepaid Electricity Sales System Part 3: Prepaid Energy Meters".This instrument complies with GB/T17215.321-2008 and 485 communication DL/T645-1997/2007 standard,Equipped with 485 and infrared communication，Remote closing switchPower outage and transmissionRemote recharge, remote meter reading and other functions.

2、 Working principle

1Working principle diagram

The electric energy meter obtains voltage sampling signals from the voltage divider, current sampling signals from the current divider, voltage current product signals from the multiplier, and then generates a counting pulse proportional to the product of voltage and current through frequency conversion. Through frequency division, it drives the stepper motor to measure electricity.

The electric energy metering pulse is sent to the CPU through a photoelectric coupler for processing, and after calculation, it is stored in the memory. The information system is managed by a computer, and through an IC card reader/writer, a certain amount of electricity and monitoring requirements are written into the IC card input table of the microprocessor system. After being processed by the CPU, it provides display and alarm status signals.

3、 Specifications, models, and technical parameters:

1. Specification and model

2. Main technical parameters:

a、 Basic error:

b、 Gas parameters (reference conditions):

Starting current: 0.4% Ib

Power consumption: Voltage line<1.0W, 3.0VA;

Current line<1.0VA

Stealth: equipped with logic anti creep circuit

Voltage range: 220V ± 10%

Working temperature range: -25 ℃~+65 ℃