mstechca
New Member
Yesterday, I was figuring out how to make the perfect 12+ to 5V converter with the fewest parts possible. So far, this is my circuit configuration:
I use a 2N4401 NPN transistor, I connect the 12V to the NPN's base through a 2.2K resistor. I grounded the NPN's emitter, and the NPN's collector is connected to VCC through a 4.7K resistor.
I connected my DMM to the collector (of the NPN) and ground. It seems that the voltage levels are highly acceptable (4.7V when 12V is disconnected and < 1V when 12V is connected), but I am more concerned with the current levels.
In order for me to make this circuit successful, I need to adjust the resistors so that I can get a logic "1" and logic "0" coming from the collector. I also want every IC that is connected to the collector to take the signals as logic "1" and logic "0".
I want to eventually use the serial port to transfer data between the PC and the microcontroller. I could end up making my own modem.
What is the best current amount to use for a logic "0"?
and What is the best current amount to use for a logic "1"?
or better yet, what are the optimal resistor values?
I use a 2N4401 NPN transistor, I connect the 12V to the NPN's base through a 2.2K resistor. I grounded the NPN's emitter, and the NPN's collector is connected to VCC through a 4.7K resistor.
I connected my DMM to the collector (of the NPN) and ground. It seems that the voltage levels are highly acceptable (4.7V when 12V is disconnected and < 1V when 12V is connected), but I am more concerned with the current levels.
In order for me to make this circuit successful, I need to adjust the resistors so that I can get a logic "1" and logic "0" coming from the collector. I also want every IC that is connected to the collector to take the signals as logic "1" and logic "0".
I want to eventually use the serial port to transfer data between the PC and the microcontroller. I could end up making my own modem.
What is the best current amount to use for a logic "0"?
and What is the best current amount to use for a logic "1"?
or better yet, what are the optimal resistor values?