Is it sage\good idea to use a d-sub cable to carry 12v. Need to use to power 12v 24w solenoid ??
Thanks
You can edit your own posts for typos etc.
I used a 100 ft DB25 to transmit 12V RS232 with no problem. I also used a 100 ft cable for 12V CMOS digital signals with no issues.
D-sub is a CONNECTOR type. You need to specify a CABLE.
You need to supply 12V at 2A over
- Some cable
- some distance
- To a solenoid that needs some minimum voltage
You need to find the wire size you need to provide that minimum voltage at the cable length you need.
terryking228:
D-sub is a CONNECTOR type. You need to specify a CABLE.You need to supply 12V at 2A over
- Some cable
- some distance
- To a solenoid that needs some minimum voltage
You need to find the wire size you need to provide that minimum voltage at the cable length you need.
In addition, all D-sub connectors have a very limited number of connect/disconnect life time. Rated for something like 25 or 50 times.
Paul
Use the AWG (American Wire Guide) to determine the resistance of a specific guage wire per meter.
Then calculate the resistance for the specified length.
Then calculate the voltage drop by E=iR (V=IR).
AWG 20 is 50mOhms/m
100m 8 0.050 ohms =5 ohms.
V = 2A5 ohms = 10V
So a 100 ft lenth of 20 guage wire would drop 10V , which, if the voltage at the source end is 12V, would
only be 2V at the other end of 100 m of 20 guage wire.
Conversely, 10m * 0.05 ohms/m = 0.5 ohms
2A 0.5 ohms = 1V, so if the cable was only 10 meters , you would have 11V at the other end.
Keep in mind , you have to multiply this time 2 since the RETURN wire would ALSO drop 1V.
In case you are wondering why this wasn't a problem with RS232 or CMOS is the current was really really small,
and thus the voltage loss was really really small.
Paul_KD7HB:
In addition, all D-sub connectors have a very limited number of connect/disconnect life time. Rated for something like 25 or 50 times.
Paul
I've seen "mating endurance" quoted at 200, 500, numbers like that. Typical current ratings 3A to 5A per pin.
The actual number of insertions is probably way higher, the quoted value is for the gold plating to be
worn through, not for the connector to fall apart! For high reliability you care about the gold plating.
I move a USFF PC to a secondary location and back each fortnight. Connect VGA on one site, DVI on the other.
Hope note to run into problems. 
I use an HDMI/VGA A/B switch
This topic was automatically closed 120 days after the last reply. New replies are no longer allowed.