7.4X5.0mm DC female Connector Where to find?

[Seekonk]

I'm trying to make a 12V power pack for my CPAP machine to use at my solar powered camp. Sure I
could just buy one. On another forum I was told that others have tried and failed.  That just made
me want to do it more.  The power pack has a modified OneWire type communication with one interesting difference.  The powered device can throw a resistor from the com line to common and an A/D reads the voltage.  The pull up resistor in the power pack identifies the rated power of the pack.  I'm not sure this has any function now and may just be a backwards compatibility for older units. That pull up has been calculated to be 2.7K, one of the resistor values mentioned in the patent.

My unit is a rental so I am not keen on just cutting up the the DC cable at this time. I've been looking
for a compatible plug and jack so I can tie in between the units and listen in.  I've ordered this
7.4*5.0mm(pin inside,for DELL) barrel plug as it has three wires.

http://www.ebay.com/itm/7-4X5-0mm-DC-Jack-Charger-Adaptor-Plug-Connector-Cable-for-HP-DELL-Laptop-CHCA-/122295444982?hash=item1c796065f6:g:6vsAAOSwf-VWaC4Z

I can not find the matching jack for this plug in ebay or Banggood.  A male/female extension cable would be acceptable.  Any ideas for a source besides tearing apart a laptop?

[kiran_shrestha]

Is this something you are looking for .
https://www.amazon.co.uk/Charger-Connector-Converter-Pavilion-15-e029TX/dp/B00PGWICAC/ref=pd_sbs_147_1/253-2610864-7162654?_encoding=UTF8&psc=1&refRID=FD507R54GA2XNKTC82Z1

[Heszu]

http://www.ebay.com/itm/10-Pcs-7-4mm-x-0-6mm-x-26mm-Soldering-Female-DC-Power-Jack-Socket-Connector-/310724545090?hash=item4858a04a42:g:~ecAAOSw241Yb7NY

http://www.ebay.com/itm/DC-Power-Jack-Socket-Cable-Adapter-Connector-Laptop-Replacement-Part-For-HP-CQ42-/172444301697?hash=item28267b3981:g:8a8AAOSwnHZYUIgj


http://www.ebay.com/itm/like/401010091827?vectorid=229466&item=401010091827&rmvSB=true


http://www.ebay.com/itm/Laptop-PJ180-DC-Power-Supply-Jack-Port-Adapter-for-HP-/311332244088?hash=item487cd90a78:m:mEEOVmGxjSQak6JaXj2N4IQ