Ok here goes, am trying to build an H-Bridge (2 actually) for a small robot for a class project. I am using 2 TIP125 and 2 TIP121 as Darlington Gates, now here is the main problem. When i try to drive a motor with a load (gearbox) the H-bridge just crashes my Microcontroller (meaning it resets it) and if I try it with the motor on its own it works perfectly.
Here is how it is Wired. I have the Tip125 on top row, 3Volt VCC coming from a source going to the Emitter of the Transistors. Base goes to a 1K resistor then to the PWM from the Microcontroller and then the Collector pin goes to the next transistor which is a TIP121. His base goes to a Resistor (1K) then to the same PWM. and its Emitter goes to the ground.
Now that would be ONE side since the other side I insert a Inverted PWM (compared to the other one).
Now like I said it works perfectly when I use a motor without load, it seems that when I try using a Gearbox motor that the Startup current is too high and tries pulling it from the MCU for some reason. I just dont get why my MCU Resets (the wheels turn for half a second) and then I have to power down the MCU and power it back up.
Also the Stall Current of the Motor is 2A, i've never seen it reach there but it normally needs around 700 mA to Start the motor then it will run fine for a Current of 300-400mA. This was tested by plugging the motor directly to the Source.
Thanks for the Advanced Help
Any thoughts will be appreciated
Marc
Here is how it is Wired. I have the Tip125 on top row, 3Volt VCC coming from a source going to the Emitter of the Transistors. Base goes to a 1K resistor then to the PWM from the Microcontroller and then the Collector pin goes to the next transistor which is a TIP121. His base goes to a Resistor (1K) then to the same PWM. and its Emitter goes to the ground.
Now that would be ONE side since the other side I insert a Inverted PWM (compared to the other one).
Now like I said it works perfectly when I use a motor without load, it seems that when I try using a Gearbox motor that the Startup current is too high and tries pulling it from the MCU for some reason. I just dont get why my MCU Resets (the wheels turn for half a second) and then I have to power down the MCU and power it back up.
Also the Stall Current of the Motor is 2A, i've never seen it reach there but it normally needs around 700 mA to Start the motor then it will run fine for a Current of 300-400mA. This was tested by plugging the motor directly to the Source.
Thanks for the Advanced Help
Any thoughts will be appreciated
Marc