I am a mechanical engineer with very little electrical background, but I was recently asked by my boss to design a simple controller board for a piece of agricultural equipment because we don't have any electrical engineers. I have already had prototypes of the PCB made, but I'm having trouble with getting them to work properly. Basically, I have input from a sensor that feeds into a series of logic gates. The logic gates decide which of two MOSFETs to activate and the MOSFETs activate a set of relays. All of the logic on the board is working correctly and it is sending a 3.6V signal (from a SN74ls08 AND gate) to the MOSFETs, but the MOSFETs won't activate.
Unfortunately I can not share my schematic on this website, but I can tell you that I used this MOSFET:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=FDD6N50TM_WSCT-ND
Also, I connected the relay similar to this (minus the LED):
http://honeyrunapiaries.com/blog/2006/blog/honey-sticks/honey-stick-machine-part-2a/
Can anyone tell me what I am doing wrong? I really don't know the proper way to choose a MOSFET so I have a feeling I may have picked the wrong type or specifications.
I appreciate any feedback you guys can give me!
Unfortunately I can not share my schematic on this website, but I can tell you that I used this MOSFET:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=FDD6N50TM_WSCT-ND
Also, I connected the relay similar to this (minus the LED):
http://honeyrunapiaries.com/blog/2006/blog/honey-sticks/honey-stick-machine-part-2a/
Can anyone tell me what I am doing wrong? I really don't know the proper way to choose a MOSFET so I have a feeling I may have picked the wrong type or specifications.
I appreciate any feedback you guys can give me!