SAE 2 Pin

Archive for March, 2012

DC Connector Terminology

by on Mar.09, 2012, under Terminology

Whenever one choses to delve into a technical topic, it’s worthwhile to begin with a study of pertinent terminology.  Generally speaking, it won’t be long before you start bumping into terms that are key to gaining an understanding.

The handy SAE 2 Pin connector is a great example.  We all had some exposure to basic electrical concepts in our early years, but not everyone has experienced continued exposure throughout their life.

If you were to begin looking for some information on the SAE 2 Pin connector, you’d probable come by it being described as a type of “DC connector”.   Now many are reminded of the terms AC and DC by the name of one of my favorite bands.  Some people might understand that what they access at a household electrical outlet is AC, and maybe even that AC stands for “alternating current”.  I hesitate to think that very many people actually have a firm grasp on just what “alternating current” means, let alone – “DC”, and “direct current”.

I’m not poking fun at anybody.  Many of us are very knowledgeable about areas of technology without any reason to have this particular knowledge.  An engineer, and the son of an electrician (early in his career), I’ve had quite a bit of exposure to electrical concepts throughout my life.

Direct Current (DC) being that which pertains to the topic of SAE 2 Pin connectors, that will be our focus in this discussion.  Any discussion of DC vs. AC is going to involve explaining that the “direct” vs. “alternating” pertains to the direction of the flow of electric charge.  Direct Current (DC) is the flow of electric charge in one direction.  Alternating Current (AC) is the flow of electric charge in both directions, i.e., “alternating” one then the other.

Alternating Current (AC) is what we access at household electrical outlets, but it also describes that which is produced by an Alternator.  An alternator converts mechanical energy (the belt driven rotation) to electrical energy in the form of alternating current.  An electrical device called a rectifier converts alternating current (which periodically reverses direction), to direct current (which flows in only one direction).  A rectifier produces a type of DC characterized by pulsating voltages and currents.  This type of DC current may then be further modified into the type of relatively constant voltage DC characteristically produced by such sources as batteries and solar cells.  There’s a lot of room for further discussion along these lines.  For our purposes, let’s leave it at the above for now.

As stated above, it is Direct Current (DC) that is produced by a battery.  It is direct current that used to charge batteries, as well.  Most electronic systems employ a DC power supply.  It follows then that a “DC Connector” is an electrical connector used in supplying Direct Current (DC) power.  There are numerous standardized DC Connectors with specific dimensions and configuration to prevent accidental connection of incompatable sources and loads.

An important aspect of a connector is its “Pinout” – which describes the function of its contacts (or “pins”).  That function may be Power (“+” positive, or “-” negative/ground), or Signal related (as in the case of a USB connector with “+” Data and “-” Data contacts).

When it came time for battery maintenance industry leader, Deltran, to select a DC Connector for the output of their Battery Tender line – the SAE 2 Pin connector was no doubt the hands-down choice.  Common in the automotive industry, its selection by battery maintenance equipment manufacturers makes sense.

Most peoples’ likely exposure to the SAE 2 Pin connector probably has to do with its use in trailer light systems.  SAE 2 Pin assemblies can often be found in the trailer lighting section of automotive stores.  Hopkins Manufacturing (the name you’re likely to most often see associated with trailer light wiring products), calls these 2 Pole Flat connector assemblies – Product No. 47965.

It was then likely to follow that upon development of Portable Solar Chargers, the SAE 2 Pin connector was to be the choice.  Industry leader, Global Solar, chose the SAE 2 Pin connector for the output of the majority of their SUNLINQ line of portable solar chargers.  In fact, their 6.5W and 12W models feature a 5-piece SAE 2 Pin accessory cable kit.

These two applications give rise to the next topic – “polarity”.  Polarity being which side of a particular connector is “hot” (+) positive, and which side is (-) negative.

In the case of Battery Tenders, the connector polarity is driven by the necessity for it to be the “protected” female side of the SAE 2 Pole connector at the end of the assembly connected to a vehicle battery to be the “hot” (+) positive side.  Therefore, the exposed pin side of the SAE 2 Pin on the end of a Battery Tender output must be “hot” (+) positve.

Portable Solar Chargers are a different situation, since the solar cells are a power source.  Their output connection must therefore be of the polarity which will have the “protected”  female side of the SAE 2 Pin connection being the “hot” (+) positive.  Accessory assemblies must then be of a polarity in which the exposed male pin of the SAE 2 Pin meant to be plugged into the output connection of a portable solar charger must be the “hot” (+) positve.

Anyone connecting leads in circuits such as those discribed above must be carefully mindful of polarity.  There may even be times when it is necessary to use a multi-tester to confirm polarity.  The continuity test function of a multi-tester can be employed to determine which contact (or pin) on the connector at one end of a lead is mapped to (leads to) which contact on the connector at the other end.

Well, we’ve covered quite a few electrical terms and concepts – enough for now.

In addition to questions of concerns in the form of comments to this Blog post, email is welcome at:  sae2pinray@sae2pin.com

We invite you to visit  www.bohemianbiker.com  for additional information – you’ll find a blog format there too!

Our products are available through our e-commerce website at:  www.solarcapitalist.com  

Solar Capitalist LLC is our sister company handling products such as those discussed above, as well as, Deltran’s line of  Battery Tenders, and Global’s SUNLINQ line Portable Solar Chargers.

Capitalize on the Sun’s Energy !

 

 

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