H bridge problem

Hello everyone :),

i am trying to build an h bridge motor controller but i am having some trouble. I am using an arduino mega, an external power source of 4 AA batteries pack(6V) and 4 2N2222A transistors as you see at the schem. When i connect the motor (small motor not sure about the specs i think its 3V or 6V) directly to the batteries everything works fine but when i connect it to the bridge its turning really slowly. All 4 transistors are connected through 470 ? resistors to seperate arduino pins. Thanks in advance.

Use PNP for the top 2 transistors, NPNs don't work well in that configuration. Just keep in mind that will invert your drive signal for those transistors, so HIGH will be off and LOW will be on for those 2 resistors. If you are not careful, you will get shoot through and blow transistors. Look at the 2n3906 for a PNP at radioshack similar to the 2n2222.

What voltages are you applying to the inputs? What voltages are you measuring at the outputs?