I previously had opened a thread regarding a 50v step up driver PCB board that I was struggling with making work:
http://forum.allaboutcircuits.com/showthread.php?p=639830#post639830
After some thought, I have determined that the problem I experienced was purely coming from using this 50v step up driver board... Which I was only using for convenience-- it was something someone else had designed specifically for firing a solenoid (which is my goal), so I figured I could just use it, but I ended up having a lot of problems making it work right in conjunction with my circuit involving the microcontroller.
So, I would like to rethink the design of my circuit and try to accomplish what this 50v step up driver board was doing.
This is what I am thinking:
My questions are:
1) I have no idea what value should be used for the diode between the solenoid terminals. How do I know what to use for this?
2) Is a 10k resistor necessary for the OUT pin of my micro controller chip? I was told that the gate pin of a MOSFET requires a resistor because 0v on the output may still not cause the transistor to close due to it acting somewhat like a capacitor. Is this correct? If so, how do I know 10k ohm is the right amount here?
3) Is this circuit missing anything important? (for longevity) Are there any safety precautions I could / should make to sure none of these components get fried?
4) Is there a reason to choose using a relay vs. a MOSFET for this? I could use a small transistor to activate a relay which could pass through the 50V. It seems like the same result, so I am just curious which is "better"? I also was told that a MOSFET requires a lot more "support" components, and that this was the benefit of using the 50v step up driver board because that had all those support components already (unfortunately that board just was not working for me).
Thank you very much for any advice, guidance, feedback, etc.
-patrick
http://forum.allaboutcircuits.com/showthread.php?p=639830#post639830
After some thought, I have determined that the problem I experienced was purely coming from using this 50v step up driver board... Which I was only using for convenience-- it was something someone else had designed specifically for firing a solenoid (which is my goal), so I figured I could just use it, but I ended up having a lot of problems making it work right in conjunction with my circuit involving the microcontroller.
So, I would like to rethink the design of my circuit and try to accomplish what this 50v step up driver board was doing.
This is what I am thinking:
My questions are:
1) I have no idea what value should be used for the diode between the solenoid terminals. How do I know what to use for this?
2) Is a 10k resistor necessary for the OUT pin of my micro controller chip? I was told that the gate pin of a MOSFET requires a resistor because 0v on the output may still not cause the transistor to close due to it acting somewhat like a capacitor. Is this correct? If so, how do I know 10k ohm is the right amount here?
3) Is this circuit missing anything important? (for longevity) Are there any safety precautions I could / should make to sure none of these components get fried?
4) Is there a reason to choose using a relay vs. a MOSFET for this? I could use a small transistor to activate a relay which could pass through the 50V. It seems like the same result, so I am just curious which is "better"? I also was told that a MOSFET requires a lot more "support" components, and that this was the benefit of using the 50v step up driver board because that had all those support components already (unfortunately that board just was not working for me).
Thank you very much for any advice, guidance, feedback, etc.
-patrick