ood Day,
Currently I am trying to put together a control circuit that controls 2 separate 24V pumps based off the input of 4 switches using FETs and resistors. What I would like is any feedback on mistakes I made and better ways of accomplishing my task. I am open to other solutions than the one I am currently pursuing. If you like to propose one, I would greatly appreciate a list of components needed so I can price it out and basic instructions on how to do it.
A short summary of where I am:
I bought the FETs and resistors and started putting the circuit together on solderless breadboards. Last night I tried testing the partial circuit (Inverters and AND gates) to verify that if the right conditions were given, I would indeed get a 24V signal out. Well, things went badly; very badly. I managed to get smoke, fire, scorched our wooden floor, melted parts of the breadboard, and even caused one of the FETS to blow its plastic cover right off the component revealing the scorched circuity beneath. Had I not damaged the floor I might have enjoyed looking at the carnage.
Here is a summary to the components I was using:
FET
Fairchild FQPF13N06L
MOSFET 60V N-Channel QFET Logic Level
Resistor
Carbon Film Resistors - Through Hole 10M Ohm 1/2W 5% 350 Volt
After building a truth table and doing some reduction logic I came to the following (where the opposite of signal A is A):
P1= ACD+ABC
P2=ABD+ACD
I was utilizing the following circuits for each gate:
I believe one mistake I made was with selecting hardware. While the FETS say they can handle up to 60V between the Source and Drain and flow up to 10A; they can only handle +/-20V from Gate to Source. If you see any more mistakes I made, please let me know.
I would also appreciate a little help selecting FETS that will work and something to mount the circuit on. Please let me know if you have any ideas.
Thank you for your time,
ForgedAscendant
Currently I am trying to put together a control circuit that controls 2 separate 24V pumps based off the input of 4 switches using FETs and resistors. What I would like is any feedback on mistakes I made and better ways of accomplishing my task. I am open to other solutions than the one I am currently pursuing. If you like to propose one, I would greatly appreciate a list of components needed so I can price it out and basic instructions on how to do it.
A short summary of where I am:
I bought the FETs and resistors and started putting the circuit together on solderless breadboards. Last night I tried testing the partial circuit (Inverters and AND gates) to verify that if the right conditions were given, I would indeed get a 24V signal out. Well, things went badly; very badly. I managed to get smoke, fire, scorched our wooden floor, melted parts of the breadboard, and even caused one of the FETS to blow its plastic cover right off the component revealing the scorched circuity beneath. Had I not damaged the floor I might have enjoyed looking at the carnage.
Here is a summary to the components I was using:
FET
Fairchild FQPF13N06L
MOSFET 60V N-Channel QFET Logic Level
Resistor
Carbon Film Resistors - Through Hole 10M Ohm 1/2W 5% 350 Volt
After building a truth table and doing some reduction logic I came to the following (where the opposite of signal A is A):
P1= ACD+ABC
P2=ABD+ACD
I was utilizing the following circuits for each gate:
I believe one mistake I made was with selecting hardware. While the FETS say they can handle up to 60V between the Source and Drain and flow up to 10A; they can only handle +/-20V from Gate to Source. If you see any more mistakes I made, please let me know.
I would also appreciate a little help selecting FETS that will work and something to mount the circuit on. Please let me know if you have any ideas.
Thank you for your time,
ForgedAscendant