Tinkering with LED strips?

[Jean-Luc Pickguard]

 

I bought a battery powered strip of LEDs from Primark this afternoon. This was only two quid so it's not the end of the world if I destroy it during my tinkering, but I thought I'd ask here if anyone has any experience in tinkering with similar strips.

 

Basically what I want to do is fix them to the bottom of a pedalboard, ideally powering them from the pedalboard power supply. The lights work with 3 × AA batteries, so nominally 4.5V.

 

Two questions I'd like answered if anyone has experience are:

 

1. Is a 9v PSU likely to work, or kill the unit?

 

2. If I can't work out the polarity of the two wires and identify this using  a trial & error methodology would getting it wrong first time be likely to kill the unit?

[tauzero]

1. Yes.

 

1a. Why not use a USB PSU? 5V is much closer to 4.5V than 9V is.

 

2. If you're going to be cutting the wires, mark one of them with a sharpie both sides of the cut BEFORE cutting, then after cutting determine the polarity using your multimeter. However, as the LEDs are diodes, they should be fine with reversed polarity.

[Gank Bass]

You can get 9v DC powered led strips for cheap on Amazon, really nice way to add some atmosphere to your stage if placed under your pedalboard or inside your cab

[tauzero]

1 minute ago, Gank Bass said:

You can get 9v DC powered led strips for cheap on Amazon, really nice way to add some atmosphere to your stage if placed under your pedalboard or inside your cab

 

 

[Jean-Luc Pickguard]

 

6 minutes ago, tauzero said:

1a. Why not use a USB PSU? 5V is much closer to 4.5V than 9V is.

 

The PSU (built into a harley benton spaceship power board) has outputs for 9v, 12v, and 18v.

[Jean-Luc Pickguard]

If I bought another identical LED strip and wired them in series — i.e. 2 × 4.5v strips connected in series powered by a 9v power supply, that should work shouldn't it?

[itu]

@tauzero answered so well to the first question! 

 

Even 48 V high wattage (CV, constant voltage) stripes can withstand reverse voltage. 

 

9 V to a 4.5 V stripe (very odd voltages, both of them) will degrade the lifetime a lot, if the system works well. Two similar systems can be connected in series to double the input voltage. 

 

It is feasible to connect the stripe to a driver before connecting the system to a line especially if the system is CC (constant current). Battery powered small systems should be able to manage hot swap, just like CV (constant voltage) systems. 

[tauzero]

1 hour ago, Jean-Luc Pickguard said:

If I bought another identical LED strip and wired them in series — i.e. 2 × 4.5v strips connected in series powered by a 9v power supply, that should work shouldn't it?

 

It should. Also, you could get to answer 1a) by using something like https://www.ebay.co.uk/itm/303990422806 - step down buck converter to a USB output, or https://www.ebay.co.uk/itm/176692251941 with solder pad outputs, or https://www.ebay.co.uk/itm/397239175045 which is cheaper but uses a 12V input (which you happen to have).