Choosing Transistors for H-Bridge

[Spanky09]

I'm designing an H-Bridge to convert the direction of this motor using my Arduino Fio:
10RPM 12V DC Motor with Gearbox [RKI-1035] - $5.00 : Robokits World, Easy to Use, Versatile Robotics Kits...

It has a very low max no-load and load current so I assume I need to find some N and P-channel MOSFETs with very low Id value. I looked on digikey for transistors with low Id values and they come up with Vds values of 200V! I don't know much about choosing transistors, but I know that I can't really supply a voltage higher than 24V for the H-Bridge.

The motor only has 10RPM so I won't be needing any PWM on the H-Bridge.

Thanks

 

[Spanky09]

I found a 2N7000 N-channel MOSFET lying around. Would its specs be ok for such a high voltage and low current motor?

 

[audioguru]

I found a 2N7000 N-channel MOSFET lying around. Would its specs be ok for such a high voltage and low current motor?

Didn't you look at its datasheet?
1) Its max allowed voltage is 60V so with only 12V or 24V it will work fine.
2) Its max allowed continuous current is 500mA so with only 300mA it will be fine but might be fairly hot.
3) Its max on-resistance averages 7 ohms when hot so with 300mA the max voltage loss is 2.1V.
Better Mosfets will cause a voltage loss of almost nothing.

Its gate needs 10V.

 

[ronv]

If your lazy (Like me) try something like this.

https://www.electro-tech-online.com/custompdfs/2011/05/sn754410.pdf

 

[Spanky09]

Thanks audioguru! I didn't understand what a lot of the values on the datasheet meant.

This is my schematic I came up with:
https://imageshack.us/photo/my-images/716/schematichbridgemotor.png/

I'm using this as my PMOS and this as my NMOS transistors. I couldn't find a DC motor on PSpice so I just put in a resistor and a inductor to represent it. The motor used in the bridge is the one in the first post in the thread.

Should this H-Bridge work? Haven't designed one before so any feedback is appreciated.