Project Report Aptomat Anti-Current Detector.pdf

HANOI UNIVERSITY OF SCIENCE AND TECHNOLOGY

SCHOOL OF ELECTRONICS AND TELECOMMUNICATIONS

PROJECT REPORTAPTOMAT ANTI-CURRENT DETECTOR

Name of students: Lê Quang Phương -20182971 Ph m Đ c Sáng - 20182973ạ ứ Ph m Thành Long - 20182966ạ

Hoàng Lâm Vũ -20182983

Name of instructor: Ph.D Đào Vi t Hùngệ

Hanoi, 1-2021

INTRODUCTION

In the modern technology life today, Biomedical Electronics is a spearhead and modern technology, widely applied in all fields of life; is a lever to help other sciences develop With the current human needs, the modernization of the medical field development based on biomedical electronics engineering is an urgent need.

As a student in Biomedical Electronics, to improve the spirit of practice and the ability to apply the learned knowledge into practice, the discovery, self-study and design of the basic software is indispensable for students To help learn and bring students closer to electronic technology, biomedical engineering design was born and made it easier for us to get acquainted and to create a strong motivation tohelp us lift High interest in learning.

With the knowledge gained from the introductory electronic engineering course and the dedicated guidance of Dr Dao Viet Hung, to explore online

knowledge, our group would like to propose the topic: "Aptomat anti-current detector ".

The goal of the topic is to create a product that detects and blocks the current

from medical devices ensure safety for users and patients, prevent risks and improve efficiency of medical equipment during treatment and rehabilitation for patients.As we all know the life span of medical devices is very high, it can be used for decades leading to the quality of the device In Vietnam, science and technology are not advanced yet, medical equipment is degraded more and more, leading to unsafety (especially electrical safety) Foreseeing this problem, our teamwanted to create a device that could detect electrical problems and fix it.

During the inevitable implementation of certain errors, we hope to receive theteachers' comments and contributions to make our topic more complete

1 Functions of Aptomat anti-shock

2 The structure of Aptomat anti-current detector

6 Design of the product

VII Solution meets requirements …

VIII Communicate results………

IX References

1 What is the leakage current?

Leakage current, also known as electric leakage current, is a physical phenomenon, the specialized term in electromechanical engineering to indicate excess current in the process of losing electrical energy, being transmitted out of the device's enclosure electrical wiring, causing accidents, electrical problems, especially dangerous to electricity users This is considered to be the cause of electric shock phenomena among electricity users, which can even lead to death when the leakage current is large, so the more you need to pay attention to these phenomena and should equip the necessary information and protective measures.

2 Reason

Current leakage phenomenon is caused by many different causes and we need to find the causes and how to fix it effectively, quickly and accurately One of the reasons:

• The electrical equipment you are using is too old: The longer the device life, the greater the risk of electrical leakage.

Your electrical equipment is too close to the wall, near a humid place: If you •place the electrical appliance too close to the wall, close to water, not dry, it will make the device wet and lead to stronger leakage, and follow Over time the leakage will get worse, as the wires become damp, degraded and lead to current leakage to the outside of the device housing.

In the process of installing and repairing electrical equipment, parts and •components of the equipment are removed and inserted in the wrong technique, in the wrong order causing the structure of the product to change, not according to

the equipment In the initial design of the product, leakage current will often occur at these joints, in these altered positions

In addition, current leakage can also be caused by external factors such as • insects, rats biting to open the power cord, maybe inside electrical equipment makes it harder to detect and check current leakage becomes difficult to control and occurs more frequently.

Current leakage phenomena are quite common in almost all electrical equipment However, depending on the level and intensity of the leakage current, it has certain effects on electrical equipment as well as the user.

3 Parameters of the influence of the probe current on the user

mA] Harm to people

AC,f= (50 -60)[

0,-1,

The muscles started to contract Pain like a needle

8 Hands do not leave electrical objects Increasing heat

20 Hands do not leave electrified objects, beginning to have difficulty breathing

The muscles contract and vibrate

90 100

If prolonged with t ≥ 3 [s] the heart stops beating

Respiratory paralysis

II- Background:

Aptomat anti-current detector also has other names: shock Aptomat, shock CB, Leak-proof Aptomat, Leak-proof circuit breaker Similar to normal Aptomat, anti-shock Aptomat has the following types :

Anti-Aptomat anti-current detector RCCD (Residual Current Circuit Breaker)

Aptomat anti-current detector RCBO (Residual Circuit Breaker with Overcurrent protection)

Aptomat anti-current detector ELCB (Earth Leakage Circuit Breaker)

Aptomat anti-current detector (anti-shock CB) has the function of disconnectingelectricity when there is leakage current to ground or someone is electrocuted In addition, Aptomat anti-shock ELCB, RCBO also have overload protection functionsimilar to normal aptomat Meanwhile, RCCB is only function against leakage current, it is necessary to combine with MCB to protect overload RCCB + MCB =RCBO.

Functions of Aptomat anti-shock:

Aptomat anti-shock with 1 phase: it compares current flowing through two cool wires and fire, if this current differs by more than a certain leakage threshold, it will disconnect the power from the load, stop the load working Manufacturers often design leakage thresholds 15mA, 30mA, 100mA, 200mA, 300mA, 500mA.

3-phase anti-shock Aptomat: it compares the current flowing through 3 phase and neutral wires, if this current differs by more than a certain leakagethreshold, it stops.

2.The structure of Aptomat anti-current detector

The structure consists of 3 main parts: Line sensor

B P rocessing circuit

Processing circuit is a system of algorithm amplifier, rectifier, filter circuitand comparison circuit to check if the probe current is greater than the safetythreshold.

different iron core makes induced current on the secondary coil of current transformer.

III, Requirements:

1.R equirements about product

They are responsible for controlling the current difference between the source and the source And each CB will be installed with an allowed level or threshold difference These thresholds have different values to suit a wide variety of applications, whether for home , industrial use and specially made for use in biomedical electronics.

When the level of leakage current through the device case or the human hand to the ground causes a difference that exceeds the default allowable threshold of anti-shock CB, the CB will immediately kick the open-circuit contact, disconnect the power immediately Therefore, the user will not receive electric shock.

The way to implement the idea is very simple, we will let 2 wires of bulb 1 passthrough the center of the current transformer and nothing will happen (bulb 1 actsas a medical safety device full and no current detection Our bulb 2 only allows awire to pass through the center of the current transformer (only the magnetic fieldgoes and no magnetic field) and the going magnetic field is not destroyed, so it willcreate an inductive current at the coil prohibition of line variables The role of bulb2 is to generate the leakage current of the medical device that we replace with bulb1 When bulb 2 turns on, a leakage current will appear and the leakage currentaptomat will work to disconnect bulb 1 from the circuit to ensure user safety.

3 Choose solution:

From the technical requirements, advantages and disadvantages that we realize during implementation and installation need to choose modules with high precision, low error, and efficient operation replace poor quality modules and components to meet the set requirements

We need to recalculate the modules, correct the errors of each component applymeasurement methods, calculate and give specific data to assess the problem avoid errors and errors in the installation process

V

Our circuit anti-leakage aptomat operation circuit includes:

A line variable

An amplifying algorithm (op-amp OP07 )

Rectifier + Filter circuit (using diodes, capacitors and ceramic capacitors)

Comparison circuit ( op-amp OP07 or IC 741 )

Relay interrupt

Main steps:

VI Develop and Prototype solution:

1 Variable line

The purpose of the product is to ensure the safety of the user and the effectiveness of the patient's treatment So we need to buy current transformers

with sufficient capacity and efficiency, because the medical devices operate at largeand continuous capacity.

Op-amp op-amp (op07) is a high precision amplifier, its deviation is about 10 It is very suitable for but the processor needs absolute precision In particular, the product is created to serve the patient's treatment and must not contain errors for electronic components The implementation of calculations is extremely complex, it is necessary to calculate appropriately for it to work in the most efficient way If we are subjective and calculated carefully, the error between input and output will be very large.

Rectifier and filter circuit

A Diode

B Ceramic capacitors and capacitors

The rectifier and filter module filter the ac circuit into a DC circuit and stabilize the current at a value corresponding to the effective voltage of the leakagecurrent for easier reference Note that when buying, capacitors and diodes are prone to fire and explosion, so we need to select them to suit the requirements of the circuit.These are the types of components with large errors, not high accuracy, leading to errors in calculation and affecting the whole circuit This will cause the circuit to work ineffectively and not to meet the customer's requirements

4.Comparison circuit

IC 741

The comparison module is a very important module this is the place to do calculations, voltage references If the leakage current exceeds the allowed threshold, the module will issue a signal asking the relay to disconnect the device from the circuit If the probe current is lower than or within the permissible

threshold, the device will still operate normally to avoid unnecessary treatment interruption of the medical device For example: electrocardiograph, ventilator, dialysis machine, dialysis The implementation of calculations is extremely complex, it is necessary to calculate appropriately for it to work in the most efficient way If we are subjective and calculated carefully, the error between input and output will be very large.

5.Relay interrupt

A relay is a module that plays the role of disconnecting a device from a circuit.It receives the signal from the comparison module when the leakage current exceeds the permissible limit.

Design of the product

Our product is still sketchy, the design is simple This is a simulation product for the project and must also improve, design in accordance with requirements

VII Solution meets requirements:

After testing and comparing the technical requirements, we found that we still have many flaws that need to be fixed for the product need to calculate the parameters accordingly, in accordance with the set requirements and choose the best and most effective solution to improve the product.

VIII Communicate results:

In this project we have succeeded in making the circuit work, carefully calculating and choosing the right components for the requirements, installing the correct circuit using MATLAB and PROTEUS software This project was completed thanks to the enthusiastic, the considerate help and the guidance of the instructor Dao Viet Hung

Development direction of the project:

In the future, we will learn more about MATLAB and PROTEUS how to write the code in MATLAB , PROTEUS in order to have an automatic process through the product We will cooperate with many people, groups in the same fieldto improve and optimize products to meet requirements

Finally, we would like to thank Dr Do Viet Hung for helping us to orient and understand more about biomedical electronics expertise, through the project we have had a lot of experience in the field and gained more knowledge personal orientation later

https://nival.vn/lang-en/aptomat-against-leaks-and-shock-notes-during-installation.html

+ Sarff, J.S; Almagri, A.F; Anderson, J.K Fusion energy 2002 19th