If you were using several of these LED light strips (https://www.defender.com/product.jsp?path=-1&id=3416918) to illuminate a space, would you wire them in series or in parallel, and what is your reasoning behind your choice?
LED light strips: wire in series or in parallel?
- Thread starter Tod
- Start date
Well Aqua Signal (Glamox) doesn't have any guidance on their website, other than they can be shortened. If you have already bought them I would expect that the instructions would answer this question. However, since they can be shortened, I would expect they could be lengthened as well. Every other brand of LED strips that I have seen or used are extendable by connecting in series. Does it look like they could be connected end-to-end?
Bottom line, I would try connecting in series (end to end) watching that you maintain the correct polarity.
Bottom line, I would try connecting in series (end to end) watching that you maintain the correct polarity.
If you wire them in series then if one fails, they all fail. Wired in parallel, if one fails the others remain lit.
In parallel each bank of lights could have a separate switch giving more opportunity to create mood lighting.
In parallel each bank of lights could have a separate switch giving more opportunity to create mood lighting.
I just wired 4 small LED lights around my engine compartment, Tod. I didn't even consider putting them in series, but I guess I could have. Because the LED's draw so little I suppose they wouldn't be effected by the small voltage drop in series.
But what do you save? In parallel, if one burns out, the others will still work.
The tricky part for me, is the small gauge wires. I think the lights pigtails were 18 gauge or smaller.
I ran 16 gauge to the first fixture. I used the smallest butt connectors that 2, 16 gauge wires would slip into, and crimped my 16 gauge feed + another 16 ga. to lead (that goes to next fixture), into one end. Crimped-tug test.
Then into the empty end of the butt connector, I inserted the 18-20 gauge LED pigtail - folded back onto the insulation, and crimped.
And so on,... through the next three LED fixtures. The parallel circuit is switched and 5 amp. fused.
But what do you save? In parallel, if one burns out, the others will still work.
The tricky part for me, is the small gauge wires. I think the lights pigtails were 18 gauge or smaller.
I ran 16 gauge to the first fixture. I used the smallest butt connectors that 2, 16 gauge wires would slip into, and crimped my 16 gauge feed + another 16 ga. to lead (that goes to next fixture), into one end. Crimped-tug test.
Then into the empty end of the butt connector, I inserted the 18-20 gauge LED pigtail - folded back onto the insulation, and crimped.
And so on,... through the next three LED fixtures. The parallel circuit is switched and 5 amp. fused.
Molex makes high quality step down butt connectors. They are a bit of challenge to source, here's one source:
https://www.waytekwire.com/products/1425/Butt-Connectors/&mfg=130&Gauge=22-18-16-14-Gauge
Waytex mostly serves the commercial market so there are minimums for both quantity and price. I've been buying a lot of my electrical products there, because the price overall is good, so long as you're willing to meet the minimums.
Yes I know they are available Dave, I was too lazy to chase them down.
Tod's option 2, series, might make this problem easier. Maybe that is what he's getting at,....
The way that these strip LEDs work is that they are made up of short sections that each have a few LEDs in series with a resistor so that they will work on 12V. Power (+12v & Gnd) is run to the next section and to each of the sections beyond. Each section has just a few LEDs and each section runs off the 12V. That is why you can cut they shorter between the sections. Conversely, you can add sections as long as you can connect to the +12v & Gnd at the end of the strip. There is a limit as to how many sections you can connect and it is limited by the size of the +12v & Gnd wires that run from the beginning end of the strip to the terminating end. In this arrangement, one short section of LEDs could fail and go dark while all the other sections continue to light. It is just like the Christmas light strings where you can plug one string into the one before it.
Think you'll need to run them in parallel. If you run two in series then the internal resistors will mean that each one will run at 6V rather than 12, and will be half the normal brightness.
I suspect that within each unit, the actual LEDs are wired in parallel. So worries about one shorting and the entire length goes dark are unfounded. I have LEDs on my back deck and a few are not working. The rest "down stream" are still fine.
You can easily add wire thickness by stripping the insulation back double the normal strip length and double it over. The idea is to insure adequate volume inside the connection. This is even legal on aircraft.Yes I know they are available Dave, I was too lazy to chase them down.
Tod's option 2, series, might make this problem easier. Maybe that is what he's getting at,....
Ken
I should have added, if you are working on aircraft make sure to calculate the circular area units properly so you do have the right amount of fill wire.
I would wire them in parallel. They are designed to work off of 12vdc, so I would feed them with 12vdc. If you put 2 in series, then each will see only 6vdc. If you put 3 in series, then each will see only 4vdc. I don't know how they will respond to that sort of change.
LEDs themselves work off of current, rather than voltage. Some LED assemblies use a resistor in series with the LED(s) to control current at a given supply voltage. Some use pulse width modulated signal generators. Some use transistor based current limiting circuits. Each type of control system will respond differently to a change in primary voltage.
As was previously suggested, read the instructions that come with them. Perhaps the issue will be addressed there.
LEDs themselves work off of current, rather than voltage. Some LED assemblies use a resistor in series with the LED(s) to control current at a given supply voltage. Some use pulse width modulated signal generators. Some use transistor based current limiting circuits. Each type of control system will respond differently to a change in primary voltage.
As was previously suggested, read the instructions that come with them. Perhaps the issue will be addressed there.
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While I have used to fold over trick many times myself, with generally good results, it is surprising for me to hear that it would be acceptable to do that on an aircraft. The parts that I have manufactured for use in aircraft have always been held to very high standards. The standards often specify details as small as what specific type of tap will be used to generate threads in a hole.
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Thanks, guys....parallel it is!
It is kind of aggravating that the wires they use are so tiny when the wire used for the rest of the circuit is almost always appreciably bigger. I suppose one way to tackle it, instead of stepping down butt connectors, would be to use ring terminals and a bus bar, although that could end up adding a LOT to the cost if there were many connections to make.
There is a number called circular area units (CAU) and it's specific to wire gauge. Each connector has a range of circular area units it can accommodate. In the Boeing process specifications, it isn't haphazard. So you add up the circular area units and use a splice that can accommodate it. some manufacturers also sell inserts that you can stick a small wire in and then insert the adapter in the connector before crimping. Those also work but require having the adapter. Just use quality components. Those automobile type connectors are garbage.
Also use a quality crimper, not the ones that you likely find in your local department store.
Not this one:
Not this one:
Ken
A ratcheting crimper is better. They insure good solid crimps.
https://shop.marinehowto.com/t/crimp-tools
https://marinehowto.com/marine-wire-termination/
Better quality ratcheting crimp tools, from companies like Amp or Molex, ensure good quality crimps. I have had poor results when I tried using less expensive ratcheting crimp tools from companies like Paladin.
There is an excellent article on terminating small wires over at Compass Marine. I bought the recommended stripper, crimper and terminals and have been very pleased with the results. http://www.pbase.com/mainecruising/terminating_small_wires