Final Year Project 2(Hardware) Week4

Title: Connecting Relay 5vdc with Microcontroller Circuit

Objectives:

• To testing the relay 5vdc with the 12vdc from car battery
• To check either the output frrom Microcontroller can connected to relay and transistor
• To test the function of IC ULN2003A that can replace the output from Microcontroller 5vdc to 12vdc

Procedure:

• Edited the relay part that combined with the transistor TIP 122 and replacing with the ULN2003A

Relay diagram that used TIP 122

• The ULN 2003A testing connection output

ULN2003A output

• The ULN2003A replacing with the TIP122

ULN 2003A connect with relay connection

Result and Analysis:

• The transistor TIP122 are control as a switching to active the relay coil, which means the output controller are connected at TIP 122 and the function are react as a ground to activated the relay coil. But the main problem is the transistor isn't give any feedback because the relay are not turn 'on 'after given output from Microcontroller 5v. 
• The specification to turn 'on' the relay are 5vdc but the MicroController output are only gieven 2.7vdc, so the relay cannot function well. 
• To solved this problem needs to find some devices that can step up/stiwch the voltage to 12vdc. because the 5vdc relay can support until 12vdc.

Relay 12vdc turn on

Conclusion

• The output fro Microcontroller are problem, it supposed to give 5vdc but the actual value when practical session are given the right feedback. So, the output must be step up to 12vdc. Due tho the simulation, the output are succesfully step up by using ULN 2003A. But, dont know about the practical is it valid or not.