[Milsurplus] Dear Smart People: RS-232 Com 1

[Gordon Smith]

Hi David,
Did a quick google search. According to this thread 
(https://forum.allaboutcircuits.com/threads/rs232-output-current-rating.64294/ 
) most RS-232 driver chips were specified for 45 mA drive, but they 
give no basis for their answer. However, if you look at this spec 
(https://ecee.colorado.edu/~mcclurel/dan83.pdf ) the maximum load 
seen by the driver chip is specified as between 3kOhm to 7 kOhm , 
which gives you a maximum drive amperage of 5 mA at 15 VDC. So I 
think the short answer is "no". But I am NO expert on this, just 
telling you what I found.

73, Gordon KJ6IKT


At 10:12 AM 2/8/2020, David Stinson wrote:
>Hello, all you folks smarter than me, especially on computers.
>Can the common RS-232 Com Port's DTR and RTS lines
>source enough current to pull-in a small 5V relay?
>
>Thanks!