I have designed this circuit to operate based off of the fact that when a transistor is in saturation mode it will behave as a switch when a voltage is applied at its base. The base voltage is greater than the emitter voltage, but the base voltage is greater than the collector voltage. The H-bridge is supposed to allow a path for a motor to be operated in one direction when a 3.3 V gpio pin is activated and then also to reverse the polarity when another gpio is activated on the second set of switches. This motor is being powered by a lithium ion battery of 3.7V. This circuit is not operating as it should and I am unsure as to why it isn't working. The green circuit shows the path for the top LED and the blue one shows the path to the bottom one. I used these LEDS to show the reverse polarity as you cant simulate a motor moving. I am unsure as to where I have gone wrong in this design. The top two transistors are in their forward active mode. VB is greater than VE but less than VC. With the VBE Junction in forward bias with the VBC junction in reverse. The bottom transistors that supply the path to ground are in saturation however as the VBC and VBE junctions both being forward biased. I would think that since these top two transistors are in active mode they would still allow current to flow, just current that is proportional to the base current. Is there a reason that I am overlooking that is causing this to not function as expected. I am trying to use these switches to provide power to a load in both polarities. It would be nice to have all of these transistors in saturation as active mode will limit the power to this load somewhat. I have tried using a voltage divider and sending the split voltage to the collector node and this still doesn't cause the circuit to operate as I would think it would. Any help or suggestions would be appreciated.
My third attempt adding pull down transistors