ElectronicStudent
New Member
Hey everyone!
So i'm working on a project and I need to draw power to run a PIC 16F87x microcontroller board from an RS-232 (DB-9) cable. After extensive research, I have discovered this can be done in two ways.
1) Apply a voltage on pin 9 of the cable and then funnel this through to the board directly or a voltage regulator.
2) Attempt to draw power from pin 4 and 5 which are the DTR and DSR pins respectively via a two resistor - diode circuits in parallel to eachother.
The first option doesn't work for me so i'm attempting the second. My question is this: how much power can I get? Voltage wise. My intentions are to take the power from these pins and feed it into the input of a +5V voltage regulator. Now for this to work, I also understand I need at least 7 or 8V at the input. Can it be done?
This is my first time using a forum so if i'm vague in any way, or you need additional info, let me know
Thanks in advance,
Electronic Student
So i'm working on a project and I need to draw power to run a PIC 16F87x microcontroller board from an RS-232 (DB-9) cable. After extensive research, I have discovered this can be done in two ways.
1) Apply a voltage on pin 9 of the cable and then funnel this through to the board directly or a voltage regulator.
2) Attempt to draw power from pin 4 and 5 which are the DTR and DSR pins respectively via a two resistor - diode circuits in parallel to eachother.
The first option doesn't work for me so i'm attempting the second. My question is this: how much power can I get? Voltage wise. My intentions are to take the power from these pins and feed it into the input of a +5V voltage regulator. Now for this to work, I also understand I need at least 7 or 8V at the input. Can it be done?
This is my first time using a forum so if i'm vague in any way, or you need additional info, let me know
Thanks in advance,
Electronic Student