Create a 50 Lite LED string In Parallel

[jack0987]

As in previous threads, my outdoor LED light strings mostly fail during the winter season. Only about 1/3 remain lit after about 4 months. Last year, I filled each socket with silicone paste to no avail.

I chose the socketed ones so that I can make them multi-colored.

I see no other option but to cut them apart and rewire each LED in parallel and use a low voltage DC power supply. Strings of 50 lites would be ideal for me.

Since adding a resistor for each LED would be rather tedious, the hope is to power entire the string at the right voltage. This is where I need help.

5 volt USB power supplies are fairly cheap and easy to come by but are to high for the LEDs. Maybe I could use them with one 2 or 3 watt resistor.

Please offer your thoughts.

 

[Nigel Goodwin]

If I use a constant current source, Do I still need resistors?

No, a resistor is used simply as a crude 'constant' current source - but a constant current source will most likely include a resistor to monitor the current, just a far lower value one.

 

[jack0987]

Looking into outdoor wire type to use, gauge, insulator, and flexibility.

Thinking 18 AWG stranded with PVC insulator but may not be very flexible.

 

[jack0987]

No, a resistor is used simply as a crude 'constant' current source - but a constant current source will most likely include a resistor to monitor the current, just a far lower value one.

The one you originally suggested -

LED Constant Current Driver Module

would not be enough for a 50 lite string, would it?
You meant it to be just an example?

 

[Nigel Goodwin]

The one you originally suggested -

LED Constant Current Driver Module

would not be enough for a 50 lite string, would it?
You meant it to be just an example?

Mainly as an example, but with constant current it doesn't matter - the current will simply be shared among the LED's (assuming they are all identical), regardless of how many there are. As it comes it's set to 600mA, but it gives instructions on how to alter it to 1A.

 

[jack0987]

Looking into outdoor wire type to use, gauge, insulator, and flexibility.

Thinking 18 AWG stranded with PVC insulator but may not be very flexible.

From what I have gathered, a silicone insulated wire with more strands may be the best for flexibility.

I have found this:

Silicone Cable Flexible Wire 8/10/12/14/16/18/20/22/24/26/30 AWG Various Colours | eBay

Flexible Silicone Wire Cable. Colours available. Can be used continuously at temperatures up to 200 °C (392 °F) Resistant to many solvents / lubricants / chemicals etc. You may also be interested in 100m of Silicone Cable.

www.ebay.com

To help, do you think I could reduce the ground wire to a #20?

 

[Diver300]

From what I have gathered, a silicone insulated wire with more strands may be the best for flexibility.

I have found this:

Silicone Cable Flexible Wire 8/10/12/14/16/18/20/22/24/26/30 AWG Various Colours | eBay

Flexible Silicone Wire Cable. Colours available. Can be used continuously at temperatures up to 200 °C (392 °F) Resistant to many solvents / lubricants / chemicals etc. You may also be interested in 100m of Silicone Cable.

www.ebay.com

To help, do you think I could reduce the ground wire to a #20?

The #20 wire is 0.5 mm2. I wouldn't run that at the 11 A that the ebay listing quotes, but up to 5 A would be fine. The current will depend on how many LED strings are in parallel.