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).

[Bleat]

I added a strip to my new pedal board setup the other day. It cost me about £6 off Amazon and has a usb connection to plug straight into the power supply. It also has a remote to change colours, or flash/ fade them. It now looks like a mobile disco! They don't stick too well to the board so I just used bits of sellotape. It's underneath so not like anyone will notice!

 

Edit to add led light fades vid:  Pedal board leds

Edited 16 hours ago by Bleat

[Delberthot]

12 hours ago, Jean-Luc Pickguard said:

 

 

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

 

I think that they all come with 5v USB A & C as well, although not in the best position for getting knocked about unless you got a right angled cable and taped it on to secure it

 

 

 

[StingRayBoy42]

I spent a lot of time researching this - I'm the bellend who decided he *had* to have retina-searing, colour-changing LED strips under all his pedalboards.

The ones I use are 12V RGB, so easy to power from a decent Pedalboard PSU (reverse polarity for extra fun!) but they need a lot of mA compared to pedals - approx 1.2A per metre.
https://learn.adafruit.com/rgb-led-strips/current-draw

If you only want one colour, the  draw is about a third of that and the PSU will probably handle it but you'll need to do the maths!

You can run them at 9V, they just won't be cornea-scorchingly bright, which would be a shame.
 

[Jean-Luc Pickguard]

9 hours ago, Delberthot said:

 

I think that they all come with 5v USB A & C as well, although not in the best position for getting knocked about unless you got a right angled cable and taped it on to secure it

I want to keep it as tidy as possible so I don't want to plug the LEDs into the USB — Just to make things a little harder for myself.