Can I send 5V power through a serial cable pins ..... (not wires)

[unclet]

If have some of the metal serial cable pin adapters with no wires attached to them yet.  I would like to use them as a quick disconnect for some wiring I am doing.  Can I can attach the 5V power RED wire from my power supply to one of the pins in the adpater without melting the pin?

I know I can not use the thin serial cable wire to transfer 5V power ....... so I am not doing this .... I just want to know whether I can attach the 5V power wire directly to the metal pin without causing fire hazards.   

Of course I would protect it with heat shrink tubing....

[DaOld Man]

You can run 5 volts through the pin. probably a lot more than that.
What is important is the amount of current you are going to pass through the pin.
I dont know how much current a serial connector pin can handle, but I would guess no more than a couple of amps.
What are you going to be supplying with this connection?
Also, you can supply 5 volts through the serial cable also, but the current draw will have to be very small. Supplying one or two LEDs through a serial cable should be ok. But I would not push much more current than that through a serial cable wire.
I found this on the net:
http://ewcap.uscarteams.org/ConnectorCatalog.htm#PinSizeAndCurrentCapacity

I would not go over 2 amps, just for safety reasons.. (But I tend to be a little over protective, just ask my daughter).

[Kevin Mullins]

I would not go over 2 amps, just for safety reasons.. (But I tend to be a little over protective, just ask my daughter).

Kinda like saying "just ask my daughters Ex-boyfriend." 

But like already mentioned, it's the current you need to be more concerned with rather than the voltage. So it boils down to what are you wanting to drive with that 5v?

[unclet]

I was going to hook up the 5V line from my power supply to go through one "pin" of a serial cable adapter.    Juut to be clear .... I am "not" going to be using the thin serial cable wire at all.

I would like to solder the RED 5V wire from my power supply to one metal pin of a "male" serial cable adapter.  I would then solder a RED wire (which goes to my LEDWiz hardware) to one metal pin of a "female" serial cable adapter.    I would then put the two serial adapters together to allow the 5V power go from my power supply to my LEDWiz hardware.

Not sure whether I can do this without creating a fire hazard.....

[Ed_McCarron]

Not sure whether I can do this without creating a fire hazard.....

As long as there are no shorts, sure.  I doubt the current the ledwiz will draw will even come close to stressing the pin.

Go ahead and power it up.  Monitor the pin.  If it gets hot, discontinue use.

[unclet]

Ok, I will do that when the time comes ......hopefully soon .... thanks

[Franco]

Im using the same method of hooking up my LED Wiz's. I'll let you know how I get on (unless you beat me 1st!) 

[mountain]

I used to be an Avionics tech and D-sub plugs were used a lot.  As a rule of thumb, we never ran more than 5 amps through a D-sub pin. If you are drawing more than that, split the load and run it through two or three pins. I think 20awg wire is the largest wire these pins can accept anyway.

One more thing, install the female plug on the supply side of the disconnect. When you unplug the two, the female plug's design will protect the circuit from shorting out against something while it is hanging there. 

[Ed_McCarron]

One more thing, install the female plug on the supply side of the disconnect. When you unplug the two, the female plug's design will protect the circuit from shorting out against something while it is hanging there. 

Sounds like a common sense thing that we all get wrong the first time.

[unclet]

I have no idea how many Amps a LEDWiz provides or how many amps I am drawing .....   


Connecting the female adapter on the power supply side makes a lot of sense..... thanks for the tip.

[unclet]

Hey .... what do you mean "split the load and run it through two or three pins"?   

Do I split one RED wire coming from the power supply into three wires and the solder each of these three wires to a different pin? 

OR

Do you mean I should take one RED wire from the power supply and solder this one wire to three pins at one time (ie: using enough solder to cover three pins at once?

OR

(something else)?

[mountain]

Hey .... what do you mean "split the load and run it through two or three pins"?  

Do I split one RED wire coming from the power supply into three wires and the solder each of these three wires to a different pin? 

OR

Do you mean I should take one RED wire from the power supply and solder this one wire to three pins at one time (ie: using enough solder to cover three pins at once?

OR

(something else)?

I would solder two wires to the power supply wire then solder each to a dedicated pin. You could use a solid lead from a diode or resistor to bridge the pins together as well, either way will split the load.

[unclet]

I am not electrically inclined so I have no idea where to get a" solid lead from a diode" or what exact resistor to use .....

BTW: All of the LEDs I bought to connect to the LEDWiz hardware already have resistors (which came with them) connected.

[mountain]

I just meant to take a piece of the solid wire off of a resistor to use as a bridge. 

[Franco]

Hmmm, I may have come across a sticking point.

Im using three LED Wiz's in my project. I was going to connect the first one using four 9 pin d subs. I was going to connect the cathodes from LED 1 to 8 using the first 8 pins of one of the d sub and then use the 9th pin to connect the common annodes, I guess this will be too much to send through the 9th pin? (LED's 9-32 was going to be connected similarly though the other three 9-pin d subs)

From what you guys are saying I could use 15 pin d subs instead and then bridge two or three of the spare pins to share the load from the common annodes?

Im using 18-19 (0.75mm^2) gauge wire if that makes a difference.

[unclet]

mountain
Does using the solid wire from a resistor matter compared to any other type of wire?

Currently I am using 20AWG stranded wire.   Can I bridge two pins with this stranded wire OR should I use solid 20 AWG wire instead OR must I use the solid wire from a resistor?

pinballjim
Do you have a picture of this micro-relay?   I have no idea what this looks like.

Franco
What is a annode?

[DaOld Man]

mountain
Does using the solid wire from a resistor matter compared to any other type of wire?

It doesnt matter what type of wire you use, as long as it is copper and will fit in the pin hole. (Solder side of the pin).

Franco
What is a annode?

Anode is one "side" of the diode. It is not the side that is marked with a band. It also connects to the positive flow of current. The side with the band on it is called the Cathode. It connects to the negative power flow.
Look at attached diagram.

The next attached diagrams shows an led, which is basically the same as a diode.
(Images stolen from http://en.wikipedia.org/wiki/Light-emitting_diode)

[unclet]

Ok, here is the picture of the back side of the serial adpater I want to use.   The GREEN lines represents the copper wire between the two pins and the RED lines represent the 5V power from the power supply.

Is this how I should be wiring it up from the power supply side?

[DaOld Man]

That should work.
If it was me, and I would do what mountain suggested.
Solder short pieces of wire to each pin, then connect them all together.
This would be a lot simpler than using jumpers between the pins.
In the attached drawing, I show how I would do it, if you are only running the power supply through this plug and nothing more.
There are nine pins, Im using 4 for positive, and 5 for negative.
This will work and should carry pretty heavy loads, but lets examine this for a minute.
The current will flow through each pin. If the resistance is exactly the same on each pin, then the current will be exactly divided between the pins.
Example: if the total current draw is 4 amps, then each pin in the 4 pin group will carry 1 amp.
But if a pin develops a bad solder joint, or breaks off, then that pins load will be placed on the other pins, making each pin carry 1.34 amps. If another pin breaks, the current on the remaining two will be 2 amps each.
So what you are doing is perfectly ok, but just keep this in mind.

[unclet]

Thanks for the picture .... I have a few more questions is you dont mind.   Sorry about this, but I just do not want to burn anything ..... hope you dont mind.

1) I need to connect the BLACK ground wire from the power supply to the serial adapter as well ..... can I use one pin by itself to do this? 

2) Does the "negative" wires going to the adapter (in your picture) represent the wires coming from the negative side of the LED light?   Hmmm .... maybe the "negative" wires represent the "ground" wire of the power supply?

3)  The adapter in the picture is the "female" serial adapter since it is safer to connect this one to the power supply.   I understand what to do with the RED wire coming from the power supply and going to the serial adapter thanks to your picture.   Now, for the "male" adapter side I believe I would have to attach 4 red wires to the same corresponding pins on the female adapter thus allowing me to attach 4 LEDs to each of these 4 RED wires .... correct?   Do I need to join all the RED wires back together on the male adapter side a well?

[DaOld Man]

(1): The black wire will carry the same amount of current as the red one, so if you use 4 pins for the red wire, you need to use at least 4 pins for the black. I showed 5 in my drawing just to make it simple. You could leave one pin put of the nine connected to nothing.

(2): The negative is the same as the ground in this situation. Black= negative on the led and it also = ground on the power supply.

(3) Yes, you can attach 4 separate leds to four pins on the male side, but these 4 pins need to match the 4 pins with red wires on the female plug. The negatives (or grounds, or black wires) on the leds can attach to separate pins on the male plug, but these pins need to match the pins with black wires that are on the female plug.

Dont forget that somewhere these leds need resistors. Each led needs its own resistor. The resistors can go between the led and the positive pin, or between the led and the negative pin.
I think Im lost here, are these leds wiring back to the ledwiz? or are they going through the db9 connector to the power supply?
Do you have a drawing you can post? I dont want to lead you astray here..
Dont worry about the drawing being crude, I just need to know what exactly you plan to do..

[unclet]

I attached a picture of how I would like to attach my LEDs.    I am going to have 4 sets of 4 LED lights connected together in parallel.    Each set of 4 LED lights will be connected to one port on the LEDWiz.   I might end up having 5 sets of 4 LES lights instead ... but the picture only shows 4 sets.

Anyway, I am going to use a molex connector to connect to 5V and GND connections to the LEDWiz.  I am also going to connect a "female" serial cable pin adapter to the power supply side (splitting the 5V power wire up as you recommended).   The associated "male" serial cable pin adapter will be used as a quick disconnect between all my LED lights and the LEDWiz.    Notice the LED lights each get 5V power and the other wire of the LED light goes directly to the LEDWiz. 

Anyway, please let me know if I can do this without burning down anything.

PS:  Each LED light has a resistor on it.  I already soldered all resistors on them properly  since I already confirmed some of them lit up.   

[DaOld Man]

I dont see any problem with fire at all.
Just wire the db9 connectors like you have it drawn. (Dont tie all the grounds together like I showed in my picture.)
Looks like you have a plan... cant wait to see some real pics of your project...

[unclet]

I will put up a bunch of pictures once I am done.   I got an electrical sander for Xmas so now I can start my wood putty'ing and sanding.  After that comes painting, etc .... and then wiring everything up.

Unfortunately I believe this might take me another month ...... finding time is hard lately.   

Anyway, thanks for the information ...... and verification ..... and patience.    Happy holidays!

[DaOld Man]

Merry Christmas....
Good luck, and cant wait to see your progress!