One other thing, I think the N-Channel you picked will work just fine. It makes all your logic "high true" then which is cleaner. Even if you are watching every penny, that 2N2222 isn't much more expensive than two diodes. In my opinion it's poor design practice to have a device that defaults to the "on" state. Without the 2N2222 when your Arduino powers up, it's outputs default to GND which will turn the P-Channel FET on nicely.
It also makes it more stable since if someone decided to give you 8V instead of 6V, you'll be in trouble with the diodes. That will work, but I prefer a good old 2N2222's collector tied to the gate which he also suggested, since it also does the necessary inversion for you. Mark suggested just two diodes in series between the Arduino and the gate. You need to "level shift" the Arduino's output to 6V. Now your gate is at 6V which the Arduino won't tolerate since it' can't get past the 5V supply. Here are some MOSFETs that I was thinking of using:Įdit: I just saw another H-Bridge post and I think we may be from the same schoolĪs Mark said: Let's say you have your supply voltage at 6V, you generally have a pullup from the gate to 6V that holds the P-FET off.
Does anybody have any suggestions or warnings? However, I'm not sure how well this would work and am afraid of switching too quickly. I'm not planning on using a MOSFET driver, so I was thinking of replacing standard MOSFETs with logic-level FETs. I'm leaning towards the first, though I'm not sure what the purpose of the two outside MOSFETs is. One that I really like is from here, and here's another that I think is fairly simple. I've found a couple of starting circuit designs that I want to start with, and make modifications to them as needed. The Arduino will be powering a lot of other things so instead of using the Arduino to directly power the motor, I was planning on using the Arduino to provide power to the MOSFET gates, and power the H-Bridge with a 6V battery. I need a little bit of help designing an H-Bridge Circuit for a 4-6V motor that draws max 140 +/- 50 mA at 6 VDC when operating in no load conditions.
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