cigarette lighter plug end getting quite warm

Those are a lousy design of plug/socket, skewed because of the requirement to disconnect when the lighter reaches working temperature. And of course a bit of excess heat hardly matters in the intended purpose, either. But the contact area is really too small for high currents, probably much smaller than the cross section of your wire. If you actually use it for lighter plugs it may have got a bit dirty from the sparking, making the contact even worse...

Hmmm, I may change it out for something better then. What might be a similar low voltage, high current quick disconnect connector I could use? I may need up to 12 VDC @ 8 amps through it.

This is the same battery connector for R/C cars, boats and planes. Capable of up to 25A at 7.5 volts. Should do the trick.

Peter Wieck Melrose Park, PA

Ham radio has the same problem and has mostly standardized on Anderson Power Pole type connectors for 12V power: Personally, I hate these, but I must admit that they do work well for high current applications.

What I prefer are XT60 60 amp connectors used by RC enthusiasts for LiPo cells: They are also available in 30 amp (XT30) and 90 amp (XT90). Note that these are intended to be soldered, not crimped.

Back to the original problem. The cigarette lighter connector was never intended to power anything continuously. It wasn't even designed to maintain a reliable connection. It's the only connector which has a spring that pushes the plug *OUT* of the receptacle instead of pushing it in or locking it in place. To make matters worse, there is usually a fuse behind the tip, with a marginal spring connection and insufficient fuse connection clips. Just count the number of crimps, connections, rivets, and dissimilar metals that the current has to go through and you'll see why it might be getting hot. At 5V 7.5A, it doesn't take much resistance to create an unacceptably high voltage drop. Try measuring the voltage drop under load across the entire connector sandwich. I don't think you'll be too happy with your measurement.

There have been attempts to standardize the cigarette lighter connector as ANSI/SAE J563: The problem is that most commodity connectors don't even come close to meeting the specifications. I think that's the cause of the heating problem that you're experiencing.

Good luck.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Yeah, this one was pulled off of an unused auto inverter. On the plug is says to not draw more than 100 W through it and it has either 12 or

14 gauge pigtails with a 10 amp fuse inside the plug. I know it must be pretty lossy since it is heating up more than anything else in the circuit.

I like the XT60 connector you mentioned after checking out its specs. I think that's the one I'll go with when I order tomorrow. And I do like the fact that it is solder and not crimped. I don't always trust crimped connections. I know it's probably my fault since I don't often have the correct crimping tool so when the wire works out, that's why, but soldering with circumvent that issue. Thank you.

Well, if you're going to use XT60 connectors, here are some hints and hazards:

1. The connectors are NOT standardized. That means that connectors from different vendors might not fit together. There are also poor quality copies. I tend to buy my connectors from Hobby King because I can be sure that they're made from nylon and not some plastic that melts as soon as I apply the soldering iron. Note the "genuine" in the description: I've bought some on eBay with mixed results. Some were really good, while others required a heat gun to form them into a usable shape.
2. When soldering the connectors, it's really easy to get them too hot and melt the plastic. Nylon is better, but plastic is cheaper and more common. To keep the pins aligned, push a mating connector together with the one you're soldering to help reduce the tendency to melt the insulation. The mating connectors do not have any way for solder to ruin your day by soldering both connectors together.
3. Use shrink tube on the wires and a big shrink tube over the connector. Follow the color code and polarity defacto standards. Pointed end of the connector is negative and black wire.
4. Gold plating is very thin but gives a good low resistance connection. However, it's easily pitted by arcing. Therefore, don't connect or disconnect the XT60 connectors with power applied.
5. Panel mounting is a bit tricky. Fortunately, there are panel mount adapters:
6. Think about high current inline blade type fuse holders: There should be at least one fuse in the circuit.

Good luck...

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Well, the Hobby King XT60's, and my 12 gauge silicon wire arrived nearly at the same time, but now I have a new problem: even with a 240 watt soldering iron (which starts to melt the XT60's), I can't solder the wire to the connectors. I've tried pre-tinning the wire first, but I can only get parts of it tinned and not the entire wire. This is never going to work for the low resistance, quick connections I'm going to need. I think I may have to revisit the crimping method unless you can suggest something I may be overlooking.....

Many times that silicon-insulated wire is contaminated by the insulation and will not take solder. Clean it with an astringent such as alcohol, followed by vinegar, then alcohol again. Then use liquid flux. It will be fine.

Peter Wieck Melrose Park, PA

What are the specs on the #12 AWG silicon wire? Solid or stranded. Silicon insulated wire is offered with waterproof insulation, which is designed to prevent water incursion through capillary action. That means no air gaps among the strands of wire, which is done by coating each individual wire strand with silicon insulation. Others such cables are filled with silicon grease, which coats the strands making them difficult to solder. For example: I used to design marine radios, where various waterproof power cables tended to cause problems for installers who were not familiar with the problem.

Does your solder have any flux inside? Have you tried using flux:

Use fairly fine sandpaper or emery cloth, about 400 grit, to scrape off whatever is coating the wire strands. If desperate, burn off the insulation with a propane torch, or use a solder pot if one is available. Scrape off the burned coating with sandpaper, and tin it with solder (and flux).

True. However, such wires are constantly being used in marine service, so my guess(tm) is you're doing something wrong somewhere. I think the key here would be to disclose exactly what type of wire you're using so we can make a determination. I have no doubt that soldering to the gold plated connectors will not be a problem.

Also, a 240 watt soldering iron is much too big for soldering XT60 connectors. Something around 80 watts with a chisel tip and some temperature control would probably solder without melting the insulation.

You can't crimp the XT60 connectors, so you'll need to start over and find a different connector. If my guess(tm) that your wire stands are coated with insulation, crimp won't work at all. Look into finding some non-waterproof #12 AWG cable.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Well, since I last wrote, I finally completed six male/female connectors. I was smart before I started in that I opened the door with a fan aiming output outside. Good thing I did because some of the nylon got to smelling.

Unfortunately, I ran out of solder and all I had left was silver solder, which I already hate. I tried using it to finish and abandoned when I started running into a lot of difficulty. So, to save my sanity, ordered some more 60/40.

All I have are some 25 watt pencil irons, maybe a 40 watt, and then we jump to a Weller 100/140 gun and 150/240 Radio Shack gun. I don't think either had the right tip. I might be able to use the Weller if I can find the correct tip (or order one).

I'll apply flame to the wires and see if anything burns off once I strip away the outer silicone shell.

This #12 is very fine silvery looking strands and very flexible. It is of the kind used in RC (radio controlled cars and aircraft) often for battery connections, etc. Because I wasn't able to finish all of the soldering today, I did put some under some screw terminals and tightened down onto the wire. The circuit powered on and no problems.

Getting rid of the cigarette lighter has made quite a difference with heating. Replaced with the chassis mount XT60 and now no heating there BUT I can't figure out how to keep the plug in the chassis when disconnecting. The whole thing wants to come out.

No, I don't have any flux. I am going to order some at the same time I order more solder later. BTW, any suggestions for a proper solder tip for my Weller 100/140 gun would be welcome or even a recommended soldering iron but I want to avoid the temp controlled ones to keep cost down.

Thanks for your encouraging help, much appreciated. I've been an electronics hobbyiest for years, but never soldered anything this large. During my radio days, sometimes a RG8 cable would have to have an end soldered on, but that was about all with the large stuff.

60/40 solder should be banned as the invention of the devil that it is. In all honesty, I would used eutectic lead-free solder before I would use that garbage.

is no plastic state.

ith no plastic state.

Peter Wieck Melrose Park, PA

Sorry for the late reply. I've been busy.

The cable insulation is not nylon. The XT60 connector is nylon. From your description, methinks the wire is a silicone outer jacket.

60/40 will work, but 63/37 is about the same price and is easier to work with. Please make sure it has rosin flux suitable for soldering electronic components. I'm partial to no-clean flux, but the rosin mildly activated (RMA) flux will work if you clean off the residue after soldering. Don't use acid core or RA flux on electronics: 25 watts is too small, 40 watts might work depending on how long you want to wait for the tip to heat and how big a tip you're using. For a 3/16" chisel tip, that could be a long time. However, don't throw these pencil irons away. They're the right size for soldering tiny SMD (surface mount devices) on PCB (printed circuit boards).

I'm not going to day anything nice about soldering guns. I have one that I last used maybe 30 years ago. The basic problems are:

1. No temperature control or regulation.
2. Not enough mass in the tip to maintain temperature.
3. Awkward and clumsy.
4. Copper expansion and contraction causes the nuts to loosen.
5. Tends to burn adjacent components with a big soldering gun tip.
6. Fairly short tip life depending on how it's used.

There are plenty of cheap soldering stations, with temperature control, and an assortment of tips on eBay or Amazon. I can recommend something if you want, but I don't like recommending something I haven't used. I'm still using 60 year old Weller soldering stations. I keep telling myself that I'll buy something better when I run out of parts, but it never seems to happen. Maybe something like this:

75 watts. Note that it comes with 10 tips. However, I can't tell if any of them are large enough to solder the #12 wire.

You could just try using an ohmmmeter to see if you get conductivity through the surface of any coating.

Looks like it's silicon insulation:

680 strands of 0.08mm tinned copper wire. I use the stuff for 12V power cord on portable 2way radios because it doesn't get stiff. It's NOT waterproof or wicking resistant, so that's not a problem. There's also no coating on the individual strands of wire.

The wire solders very easily. In fact so easily that I have problems with the solder creeping up the cable and making the first cm or so rather stiff. That also begs the question why are you having problems soldering the wire and XT60 connector? As you can see from the HobbyKing.com URL, they supply pre-made cables with XT60 connectors. It should be really easy. My guess is:

1. Bad tip on the soldering gun.
2. Bad soldering gun (not hot enough).
3. Bad solder, wrong solder, no flux, wrong flux, etc.
4. Grease or oil on the connection.

Ok, that works. However, I think you'll find that the screws will chew up the fine wires in the cable. Same problem with crimping. There's an amazing amount of "air" between the wires. If you screw down or crimp something to the wire, it will initially feel tight. However, as you move the cable around, the empty space will fill up with wire strands and loosen the connection. It's worse with a screw, which will cut strands that eventually fall out. Screws and crimps work best with a few strands and heavier gauge wire. For your application, soldering is the only way.

XT60 panel mounting kit: There are others. I'm lazy and just glue an L-bracket to both sides of the XT60 connector.

See my comments about flux, solder, and soldering irons.

Coaxial cables are difficult to solder. I use crimp type coax connectors whenever possible:

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

No problem. I ran out of supplies anyway, so no matter.

No, the type of tip the Weller had was a wide, flat cutting tip. It was really easy to touch the nylon part of the XT60's while trying to solder the wires on. The wire itself does have the silicone jacket, yes.

k, but 63/37 is about the same price and is easier to

Actually, 63/37 is what I am getting not the other. It does have rosin, but I also ordered some pure rosin flux.

#5 definitely with the nylon part of the XT60's!

Thanks, I'll take a look.

Good idea! I will do that if necessary.

How about makeshift ways of keeping the connectors and wires steady? This was no picnic. I used to have some "helping hands" but of course couldn't find them when I needed them, so ordered some of those too. I really think the solder I was using had little or no flux too. And of course wrong soldering iron tip.

I don't like the wires under the screws. I may have to look for a solderable connector similar to the crimped type:

I'm lazy and just glue an L-bracket to both sides

Excellent idea! What type of glue will allow metal to nylon bond? I have some leftover JB Weld.

I hated soldering on connectors onto RG8! Eventually, I started purchasing cables with connectors already soldered on, plus there was a radio shop not too far away that would do it free if RG8 was purchased from them. Haven't had to solder it in nearly 3 decades though so not concerned.

Soldering the pl259 to coax was not too bad for me once I either filed the chrome plating off the part I wanted to solder, or even better was going to the silver plated type. At that time I was using a Weller

100/140 watt gun. I never did like the BNC or N connectors for putting the coax on. Too much mechanical work

Then the crimp connectors came out and I have been using them for a long period of time. Really handy when putting connectors on where you are a long way from the AC power.

I have gone to crimping all most all wiring that I can for all types of plugs.

YOu mentioned a wide flat blade. That is probably the one ment for cutting plastic and not soldering. I have a few but never used them. Not sure what the tips I use are made of, but they are silver colored instead of the more common copper tips. However they look like the copper ones.

I have not used the connectors like you mentioned. They appear to be similar to other connectors where you solder the wires to. For those I fill up the cup on the connector and tin the wire. I usually cut the insulation of the wire off about twice what I want, tin the wire and then cut to length. Then heat the connector and push the wire in the cup after the solder melts.

I saw a you tube that does something similar,but he has way too much solder on the wire. YOu want just enough to hold the strands together.

I still have, purchased around 1990, some Archer 64-005 solder. It's

60/40, 0.032" (about 0.8 mm, finer than typical) "rosin core". I'm running out of it, but that's been my go-to electronics solder since I bought it. I have a 23W / 33W swappable pencil soldering iron from the same period (and also Radio Shack). It has served me well, but I have been thinking maybe time for an upgrade. For one thing, I've never really been able to work with silver solder easily.

The advantage of 63/37 is what? Just lower melting point? Anything else? I know it is the "eutectic" point (ratio with lowest possible melting point), but I don't know if that conveys other desirable traits.

Maybe it herectical to suggest this, but, I'd consider using a big tip and preheating it with a torch. That is heat the soldering iron tip with a propane torch and then just rely on the heating element in the iron to keep it from cooling too fast.

I remember my grandfather's soldering irons, one of which was completely unpowered and relied on stored heat. (Most of the images for "soldering iron vintage" at ebay are similar designs.)

Are the typical soldering stations one sees (like the link I dropped for the 75 watt one above) suitable for basic SMT work? I know for some SMT you need an oven in order to heat parts unreachable with an iron, but consider the case of clean removing an SMT LED from a board because not everthing needs a power on light. I don't have really fine tips for my current iron, and SMT is not something I've tried.

Elijah

------ has other solder for non-electronics use, such as ballast

The main advantage of the 63/37 solder is that as it cools it turns from a liquid to a solid. Any other mix will go through what is called a plastic state. If the wires are moved during that time you get what is called a cold solder joint. It will have to be reheated and maybe some more flux added.

For about $ 75 or less you can get a hot air rework station from ebay. This will not hold up for commercial work, but good enough for the hobbiest that may use it once a month. It is a box with a fairly high wattage iron with changable small tips. Reason for high wattage is the tip is so small for smd that it will not hold much heat. There is also a wand that blows hot air out of a small hole about 1/4 inch in diameter. Both are temperature controlled. You can get a life time supply of some .015 solder for about $ 25.

Get an Amscope se400z microscope so you can see the small parts for about $ 200. The smd is really easy to work with if you spend a few dollars and get the tools to woek with. Lots of videos on Youtube to show how.

Years ago I moved up from a cheap non-regulated soldering pencil, to a Weller WTCP-series (with the ferromagnetic-tip switch) and found it quite an improvement. More recently I bought a used Metcal, and find it very worthwhile... fast to heat, doesn't overheat, and the tip temperature recovers quickly.

I still use a propane-fired pen, or one of a couple of Weller soldering irons for some jobs, but the Metcal is my go-to for PCB work.

The whole eutectic alloy freezes (and melts) at a single temperature, so the molten mass cools to a solid as a whole, rather than going through a "slushy" temperature range (the slush being a mix of solidified crystals and liquid) as 60/40 does. This can (I understand) reduce the risk of a "cold" solder joint where the joint was moved while the solder was solidifying.