geodude
Newbie level 1
Hi friends,
I have connected NPN transistor( BD139) amplify the microcontroller's(ATMEGA 16) small output current to about 600mA. I have connected 6 such transistors to different pins on mcu. The transistors are in parallel with a rectified 6 volt-5 AMP source, so the net current required is about 6x 600 mA=3.6 amps. I have other power supply of 12 V- 500 mA for powering mcu. I need to connect the grounds of two supplies to make one common ground. Is there a chance that the huge current 3.6 amp may return from the low current source ? Is there any circutry to protect the MCU from such mishap ?
I have connected NPN transistor( BD139) amplify the microcontroller's(ATMEGA 16) small output current to about 600mA. I have connected 6 such transistors to different pins on mcu. The transistors are in parallel with a rectified 6 volt-5 AMP source, so the net current required is about 6x 600 mA=3.6 amps. I have other power supply of 12 V- 500 mA for powering mcu. I need to connect the grounds of two supplies to make one common ground. Is there a chance that the huge current 3.6 amp may return from the low current source ? Is there any circutry to protect the MCU from such mishap ?