Replacement of Mechanical Relays with MOSFET Devices

1
Replacement of Mechanical Relays
with
MOSFET Devices
United Arab Emirates University College of
Engineering

• Team Members
• Tareq Sameer Mushtaha
  200235764
• Bilal Fouad Al- Zobeidi
  200235559
• Advisors
• Dr. Ali Assi
• Dr. Abbas Fardoun

2
Outline

• Acknowledgments
• Executive Summary
• Introduction
• Background Theory
• Methods Techniques
• Circuits Definition
• Results Discussions
• Conclusion
• References

3
Acknowledgments
4
Introduction
Graduation Project
Graduation Project I
Graduation Project II

• Investigate techniques to
• implement electrical switch.
• Simulating the models.

• Implement and Test the circuits.
• Results analysis

5
Executive Summary

• Objectives
• Investigate the feasibility of replacing a
  mechanical relays with MOSFET switch that
  occupies smaller space in electrical and
  automotive systems
• Procedure
• Studying MOSFET switches and Mechanical Relays
• AC Drive Steering Wheel System as an Application
• MOSFET and Relay Components
• MOSFET and Relay Circuits
• Simulation
• Implementation
• Tests

6
Background Theory

• MOSFET
• Metal Oxide -Semiconductor Field-Effect
  Transistor
• Channel of n-type or p-type semiconductor
  material

Fig. 1 MOSFET Structure Circuit
7
NMOS PMOS
Fig. 2 NMOS and PMOS
8
MOSFET body diode

• p-n- junction Forms an effective diode, in
  parallel with the channel
• negative drain-to- source voltage can
  forward-bias the body diode
• diode can conduct the full MOSFET rated current

Fig. 3 MOSFET body diode
9
MOSFET switch

• Typical switching frequency tens and beyond
  hundreds of kHz
• On-resistance increases rapidly with rated
  blocking voltage
• Easy to drive (voltage driven)
• Typically part is selected on the basis of
  on-resistance

10
Background Theory

• Mechanical Relay
• Electrical switch that opens and closes under the
  control of electrical circuit
• A coil of wire that, when electricity is sent
  through it, becomes a magnet.
• The magnet is attracted to iron objects.
• Exert a pull or push from a distance, and under
  electronic control.

11
Background Theory

• Mechanical Relay

Fig. 2 Mechanical Relay
12
Background Theory

• Why Replacement!
• Size
• Cost
• Life time
• Complexity
• Manufacturing
• Switching Speed
• Possibility to add it to existing die

13
Background Theory

• Application

Fig. 4 AC Drive Steering Wheel System
14
Methods Techniques

• List of components
• MOSFET
• Mechanical relay
• Other components
• Single drivers
• Diodes
• Inductors
• Resistors

15
Methods Techniques

• MOSFET
• IR1312 MOSFET /power MOSFET family/ Farnell
  Company
• NMOS transistor with
• VDSS 80 V
• ID 95 A
• maximum Rds(on) is 10 mO

16
Methods Techniques
Fig. 5 MOSFET Switching Time Test Circuit
Fig.6 MOSFET Switching Time Waveform
17
Methods Techniques

• Mechanical Relay
• High Power Automotive Relay/ CB-Relays family/
  Installation Middle East Company
• Rating current 40A at 85OC,
• Low temperature rise which helps in the
  performance of switching operation
• Low contact resistance ? 2.6 mO

18
Fig. 8 Schematic Diagram for Automotive relay
Fig.7 Relay Tests
19
Methods Techniques

• Single Driver
• IR2106 DIP single driver/ Farnell Company
• High and low side driver
• It has 8 pins from DIP case style
• Voltage range of 10?20V
• Temperature range of -40?125 oC
• Base number of 2106

Fig.9 Single Driver Input/output Diagram and
Switching Time Waveform
20
Circuits Definition
Fig. MOSFET circuit
21
Circuits Definition
Fig. Relay circuit
22
Results Discussions
23
MULTISIM Simulation
MOSFET Circuit
24
MULTISIM Simulation
Relay Circuit
25
Implementations Measurements
26
Implementations Measurements
Table 1 Comparison criteria
27
Conclusion

• Presented work shows possibility to replace
  mechanical relay with MOSFET device
• Key characteristics of both switches has been
  presented discussed
• Mechanical relay replacement is possible

28
Cost Estimation
29
Cost Estimation

• Cost estimation and management is the most
  important issue to be considered in any project.
• This importance is reflecting on the decisions to
  be taken according to the budget allowed for the
  project.

30
Cost Estimation
31
Impacts
32
Economical Impact

• No direct economical impact
• Circuit can be used to build higher order
  systems that can have an economical impact in
  places where these systems can be implemented
• Integrated circuit, the successful
  implementation of this circuit at UAEU will
  support efforts in car manufacturing and some
  other applications

33
Environmental Impact

• During the phase of designing this circuit more
  specifically in using Laptops, MULTISIM and lab
  tool to simulate and test the circuit
• No negative environmental impact

34
Safety Impact

• During the design phase, we believe that no
  safety measures should be taken into account

35
References
1. www.tycoelectronics.com 2.
www.rsuae.com 3. http//en.wikipedia.org/wiki/MO
SFET 4. Mechanical relay replacement,
individual research proposal, Fardoun Abbas
Ali Assi 5. www.farnell.com
36
Thank You...