Electronics > Beginners
Circuit design, lost on what's probably simple transistor logic
blazini36:
Actually I made a pretty bonehead mistake there. I tried dropping the mosfets like you suggested with no luck, then I reaslized I was testing with a 2N7000 (TO-92) and when I updated the schematic I used a SMD 2N7002 because the board will use the SMDs. I didn't realize that the source and gate pins swapped |O. Hopefully this makes a little more sense. I'm using the 2N7000 because it's what I have on hand to test. I have a box of assorted transistors coming in today so if there is a better alternative I'm all ears but so far this is what I've gotten to work.
Updated schematic.
Wimberleytech:
--- Quote from: blazini36 on December 04, 2018, 04:12:11 pm ---Actually I made a pretty bonehead mistake there. I tried dropping the mosfets like you suggested with no luck, then I reaslized I was testing with a 2N7000 (TO-92) and when I updated the schematic I used a SMD 2N7002 because the board will use the SMDs. I didn't realize that the source and gate pins swapped |O. Hopefully this makes a little more sense. I'm using the 2N7000 because it's what I have on hand to test. I have a box of assorted transistors coming in today so if there is a better alternative I'm all ears but so far this is what I've gotten to work.
Updated schematic.
--- End quote ---
Better. However, when the mosfet is off, there is nothing determining the potential on PWM pin. It needs a resistor pullup to 5V.
blazini36:
Any Better?
Wimberleytech:
--- Quote from: blazini36 on December 04, 2018, 05:15:29 pm ---Any Better?
--- End quote ---
That oughta do it!!
blazini36:
Thanks for the help bud. :-+
Navigation
[0] Message Index
[*] Previous page
Go to full version