Small 12v 4 Pole Connector.

[demitrix]

Im installing a carpc in my car and ive come across a small issue, the power supply has two switches you can use to power on an amp and one other device, they both use +12v. Problem is space on the back of the pc is very limited so i need a very small connector that has 4 poles and can handle the +12v from the psu. Something along the lines of a 4pole 3.5mm plug like such would be perfect.
**broken link removed**

 

[Hero999]

The voltage should be no problem, it's the current that counts.

What's the current ratingof the connector and what current doe your PC require?

I think you need a bigger connector.

 

[Dean Huster]

I've never seen a 3.5mm with more poles than the typical tip-ring-sleeve, although Ampex used a 1/4" phone plug in their portable cassette recorder with tip-ring-ring-sleeve to handle microphone and "pause" switch.

Why not just use a regular mini-DIN as used on a computer mouse?

Dean

 

[Sceadwian]

I've seen connectors like this used on inexpensive PDA's that use them for power and serieal communication. There's really no problem with using them, you just have to keep in mind as you insert the plug into the connector the ring closest to the tip is going to contact the lead for the ring furthers from the tip on it's way to it's proper position, so you might accidentally apply 12 volts to an internal ground line. If you're talking anything over a few hundred ma's don't do it though. A 4 pin keyed IDC type square header would take up the same space as the jack and not allow improper connection. What kind of currents are you talking about?

 

[demitrix]

Well i dont have a multimeter handy to test anything and its not a really published fact but heres a reply i got on another forum

The current is very, very low.
It wasn't enough to even turn on a 30A automotive relay...
I believe that relay had an 88Ω coil.

As for the other switch i dont actually think it has more then 5v goin through it, as its the same as a motherboards on switch.

Thanks for all the help.

 

[Sceadwian]

You could probably use that style of connector if you really wanted to since it seems to be under 150ma's but you have to put voltage protection on every pin as said before the tip of the male plug will come into contact with the 4th ring of the female connector and work it's way up possibly contacting both the 2nd and 3rd rings at the same time. You could definitly do better.

 

[demitrix]

Would a DB-9 be able to do it? I acutally have another thing i need jumped internally so now i have +12V, 2 Switches goin out and a switch for an internal jumper so a total of 7 wires now i need to be connected somehow...

Edit: I actually have another +12V @ 8A and a ground so it would take up the last 2 wires...

 

[Sceadwian]

8 amps through a DB9 cable will just about cause it to burst into flames, so that's right out. You're going to want a small molex connector, perhaps something like the auxilary 12 volt connector (four pin molex) that some motherboards/power supplies use for power hungry PC's. That's just for power, your signal/switch lines you're going to want to run on a seperate connector.

 

[demitrix]

Ok the monitor would only be using about 1A but i found a better solution anyhow, i think...
https://www.radioshack.com/family/index.jsp?categoryId=2032286&cp=2032058.2032231

 

[Sceadwian]

Yeah, those are the molex connectors I was talking about, though some of them have a lot more connectors. Apparently I was using the wrong terminology. I was thinking of the 4 pin PC style one on that page, I consider anything on that page a molex connector. I am a little confused though as you said the 12 volt line supplied 8 amps, and then you said it'll only be using 1 amp? There's a big difference between 1 amp and 8. A DB9 connector can handle 1, it can't handle 8.

 

[demitrix]

Well its a 12v PSU rail, but the only device that would be running on it would require 1A, but im just gonna use one of those 9 pin molex i think it will work the best.

 

[hjames]

Molex (the company) makes *lots* of connectors, and trying to dig through their website will make you cry...

I think the rectangular power coonectors in standard PC's are either 3mm or 3.5mm pitch. Molex makes a 2mm line with some wire-to-wire connectors that is pretty small and probably handles a couple amps. The ones on the radio shack page have been around for a really long time, and they're pretty common.

Digikey, Mouser, Newark are really the best places to look for connectors - download the PDF catalogs and browse through the pictures to see what sort of connectors would fit in your application. All of them do small quanity orders, the main issue is whether you're willing to spend $5-$10 on a connector since the typical markup on single unit purchases is almost painful.