multi-pin dc power connectors

I need an 8 way dc power connector to use with my medium sized tube mixer designs.  For smaller designs with fewer supply rails I have been able to get away with a 6 way XLR but the 8 way ones doon't cut it for the currents or voltages I need. For the heater supply I really need pins capable of 16 amps and for the HT they need to be able to carry at least 300V.

Holger has pointed me at some really chunky rectangular ones made by Harting (Han series I think) that he used for the Kaessemaschine but I was hoping to find something circular and a bit smaller. Any ideas?

Cheers

Ian

Hi Ian
Mil types are good, however they are $$

https://www.connecticc.com/products/suppliers/amphenol/amphenolaerospace.html?gclid=EAIaIQobChMInZSdnIXt2gIVhMVkCh3KFwvPEAAYASAAEgJ4r_D_BwE

Duke

Mil connectors are what I’ve used, too. Mine were 6 pin and 5 pin. Got em on eBay for pretty cheap. Found this 8 pin. Pricier than what I paid but not the worst i’ve seen at less than $9.

https://www.ebay.com/itm/Military-8-Pin-Twist-Male-Female-Cable-Connector-F8P-/290571855732

Cheaper ham types here:

https://www.ebay.com/itm/12-8-Pin-Army-Military-Aircraft-Radio-MIC-Connector-8A114-/201223724089

Audio1Man said:

Hi Ian
Mil types are good, however they are $$

https://www.connecticc.com/products/suppliers/amphenol/amphenolaerospace.html?gclid=EAIaIQobChMInZSdnIXt2gIVhMVkCh3KFwvPEAAYASAAEgJ4r_D_BwE

Duke

Click to expand...

MIL spc does not necessarily mean high currebt or high voltage capability. That is as much down to size and spacing of pins as anything.  For instance, Amphenol also do an Eco-mate series for industrial use which has the right kind of contacts at lower prices. Just can't seem to find both mating halves from one supplier!!!

Cheers

Ian

rackmonkey said:

Mil connectors are what I’ve used, too. Mine were 6 pin and 5 pin. Got em on eBay for pretty cheap. Found this 8 pin. Pricier than what I paid but not the worst i’ve seen at less than $9.

https://www.ebay.com/itm/Military-8-Pin-Twist-Male-Female-Cable-Connector-F8P-/290571855732

Cheaper ham types here:

https://www.ebay.com/itm/12-8-Pin-Army-Military-Aircraft-Radio-MIC-Connector-8A114-/201223724089

Click to expand...

Yes, I have seen these eBay ones. The trouble is not one of them actually specifies the current and voltage ratings. They look like they might do the job but I don't think I am going to trust 8 amps of heater current and 300V of HT  through one of them.

Cheers

Ian

Probably wise to be cautious.  FWIW, a quick look at the MIL 5015 spec shows the max continuous AC voltage for each “service rating”, lettered A through E, plus a rating of “Instrumentation”.  No DC or current levels are specified.  At sea level,  the lowest is 1000 VAC for Instrumentation. Lettered ratings A - E are specified as:

A - 2000 VAC
B - 4500 VAC
C - 7000 VAC
D - 2800 VAC
E - 3500 VAC

Amphenol has an aerospace line (translation: not cheap) that is made to the  5015 spec. Service ratings are specified for each connector. Link:

http://www.amphenol-aerospace.com/pdf/catalogs/5015_Catalog.pdf

You can probably find knockoffs on eBay (though you probably can’t count on adherence to the spec) for less cash.  But at least that gives some frame of reference.

Thanks for the info rackmoney. Very useful.

Cheers

Ian

Edit: I just discovered that Farnell not only has a section for MIL spec circular connectors but it also has one for MIL spec equivalent ones which are presumably cheaper.

I have been looking at these MIL equivalent connectors. There seems to be a considerable price hike as you go from size 16 to size 12 contacts (which is what I need for the heaters). So I looked at 10 size 16 contact connectors (with the idea of doubling up the heater connections) and these seem to be more reasonably priced.

Cheers

Ian

First thing to come to mind would be standard TE / Tyco CPC connectors. There are ones with two conductors quite a bit larger than the others. It is a little bit of a unique part but you might find something that is stocked well enough because other commercial products use it.

Something like this for example maybe (largely picked at random though):

TE Connectivity AMP Connector 213893-2

squarewave said:

First thing to come to mind would be standard TE / Tyco CPC connectors. There are ones with two conductors quite a bit larger than the others. It is a little bit of a unique part but you might find something that is stocked well enough because other commercial products use it.

Something like this for example maybe (largely picked at random though):

TE Connectivity AMP Connector 213893-2

Click to expand...

I did find an AMP connector (PT series I think) with two size 12 contacts (22A) and 6 size 16 (7A) contacts but it was £50 per mating half. I will check out the CPC range to see if that is more cost effective.

Thanks for the tip.

Cheers

Ian

You could always split it across two connectors. That might seem to be admitting defeat but there would be upsides: One high-voltage, low-current connector and one low-voltage, high current one

A relays to verify both are connected before the psu fires up and you're "Golden", as they say in Hove

Nick Froome

> I really need pins capable of 16 amps

Your house is full of 13 Amp pins. Can you imagine eight of those in one shell??

Clearly you want a "mix" of big pins and small pins. That limits your choices unless you have National Budget.

Yes, the UK 13A pin is generous. US 15A/20A pins are smaller, but also trouble-prone.

Paralleling is dubious. Pins have various contact resistance. One "good" pin can hog MOST of the current. Sometimes the heavy current degrades the contact and it tends to self-equalize. But I have seen parallel contacts who did not get that memo.

A functional and VERY inexpensive alternate is PC motherboard power connectors. You want "extender" (M and F with a foot of wire between; unless it is convenient to have pin-header on your mixer).


TH has an essay on these connectors and ratings. (Skip way down to ATX; you can't get AT-type today).
https://www.tomshardware.co.uk/power-supply-specifications-atx-reference,review-32338-7.html
Today the 24-pin version is more common:
https://www.tomshardware.co.uk/power-supply-specifications-atx-reference,review-32338-8.html
My experience is that cheap ATX connectors have no trouble with 80W 5V (16A) on four pins. They are widely used to ~150W 5V or 3.3V (30+A). I do not know if the "Plus" design is common.

Current rating depends on wire-size... they depend on the wire to draw-out heat.

The Molex spec says 600 Volts. As a double-shrouded connector it is hard to imagine any trouble at 300V.

Mating is tested (for Molex) to 30 cycles. This is far more than most PCs see. It may be an issue in prototyping or a console which is regularly dismantled and serves several decades.

There is a 4-pin variant used on most modern motherboards as CPU supply (12V to an onboard 1.97V converter). This would surely do your heaters; the other-stuff can use a cheap connector.
https://www.tomshardware.co.uk/power-supply-specifications-atx-reference,review-32338-9.html

I don't have to tell you that 48V 2A is much less copper and contact than 6V 16A, if you can series-string your heaters.

ruffrecords said:

I need an 8 way dc power connector to use with my medium sized tube mixer designs.  For smaller designs with fewer supply rails I have been able to get away with a 6 way XLR but the 8 way ones doon't cut it for the currents or voltages I need. For the heater supply I really need pins capable of 16 amps and for the HT they need to be able to carry at least 300V.

Click to expand...

Just an idea, but the Neutrik speakon 8-pin version is rated 30 amps RMS continuous, 40 A at 50% duty cycle (audio). Rated at 250V, but it doesn't say AC or DC. They are really cheap, and are a round twist-lock latching style with wiping action.

They also say "Attention---speakON is NOT to be used as an AC mains or power supply connector!" Then again, I recently used the 4-pole version for field and armature windings on a 1/4HP variable DC drive, and Neutrik hasn't shown up yet to confiscate all my connectors.

If you do go with them, don't bring that supply anywhere near my PA stacks.

http://www.neutrik.com/en/speakon/fc-series/nl8fc

PRR said:

Clearly you want a "mix" of big pins and small pins. That limits your choices unless you have National Budget.

Click to expand...

See attached pic for what he needs. ;D

Paralleling is dubious. Pins have various contact resistance. One "good" pin can hog MOST of the current. Sometimes the heavy current degrades the contact and it tends to self-equalize. But I have seen parallel contacts who did not get that memo.

Click to expand...

True, bit there is a workaround. Instead of running a single12awg to four pins, run four 18awg the full length of the umbilical, each to it's own pin. "Ballast resistors" to better share the current, plus all wires can be the same size in the cable that way.

Pic: Power supply output connector for a carbon-arc followspot. Can you guess which pins carry the 105 - 115 amps of arc current?  ;D

Gene

What about the rectangular connectors as used by Cadac years ago, shown on the RHS of http://www.cadac-sound.com/tempimg/contentimg/faq_concret-touring225.gif .They were nice (from memory), but I can't remember their name/manufacturer

squarewave said:

First thing to come to mind would be standard TE / Tyco CPC connectors. There are ones with two conductors quite a bit larger than the others. It is a little bit of a unique part but you might find something that is stocked well enough because other commercial products use it.

Something like this for example maybe (largely picked at random though):

TE Connectivity AMP Connector 213893-2

Click to expand...

I have looked into this a bit more and I think this is the way to go. Of course Mr. Murphy was having a fine old time with me. I was looking for 8 pole connectors and there is an AMP mil style connector with 2 big contacts and 6 regular ones. Of course there is no CPC equivalent. But there is a 10 pin version with 8 regular pins and 2 fat ones but then I wasn't looking for 10 way connectors. Ho hum.

Anyway, these are 600V rated and the big pins can carry up to 50A which will do nicely. Also they are not too expensive. A pair of shells costs less than £20 and even the heavy duty contacts are only 38p each.

Cheers

Ian

Edit: Actually the power pins are not cheap. Rather than £3.87 for 10 they are £3.87 each  and the minimum pack size is 10 so nearly £16 per mating pair.

Note that those "Series 6" parts are reverse sex so maybe put the receptacle on the power supply and just hard-wire the cable w/ plug to the unit being powered. Actually the more I think about it, this is probably ideal anyway because the most hazardous scenario would probably be if the power supply was on but without a plug attached. So with a reverse sex receptacle on the PS you don't have any pins that someone could touch accidentally.

squarewave said:

Note that those "Series 6" parts are reverse sex so maybe put the receptacle on the power supply and just hard-wire the cable w/ plug to the unit being powered. Actually the more I think about it, this is probably ideal anyway because the most hazardous scenario would probably be if the power supply was on but without a plug attached. So with a reverse sex receptacle on the PS you don't have any pins that someone could touch accidentally.

Click to expand...

Yes I was thinking along the same lines. Also stops people extending the the power cable. Just waiting for Farnell's site to come back up.

Cheers

Ian

Ian,
Why  not  use a Neutrik SPEAKON  8 pins ?
Reliable and cheap

I have used it  several  times for PS of  consoles  like Trident or MCI

Best,
Guy

Theres a guy called Roy over in Southampton who runs a place called 'Electrojumble' .
He's got a good selection of the bayonet and screw-lock  military connectors and plug ends ,might be worth an email to see if he could source what you want , Some of the stuff is used and some is old stock, overall value is very good though .
Ive got several boxes of bits over the years and its always a pleasure doing business with him .
http://electrojumble.org/Connectors_Military.htm

He does seem to have the types with both large and small sized contacts too ,here,
http://electrojumble.org/DATA_4/Misc-Connectors.htm   

I have used a four pole speakon to power a tube project, I used a big metal cabinet mounting socket on the psu end with no possibillity of plugging a 1/4 inch jack  for obvious reasons , even though its only for my own use it carrys a 'high voltage' danger of death warning right next to it .

guy_4 said:

Ian,
Why  not  use a Neutrik SPEAKON  8 pins ?
Reliable and cheap

I have used it  several  times for PS of  consoles  like Trident or MCI

Best,
Guy

Click to expand...

Te 8 pin Speakon is a great connector. I would use it except the data sheet specifically says it is not to be used for mains or power supplies.

Having said that, it has plenty of current carrying capability and is rated at 250V rms so I may just try a pair.

Cheers

Ian