LED Rope Light Controller Memory

[AberDino]

Hello all,

I found this forum in my quest to adapt my LED rope light controller so that it remembers the last setting it was on. I am technically minded and comfortable soldering in/out circuit board components, but I don't have an electronics background so rely on sites likes this to find a solution.

Back in 2016 I purchased a LED rope light with multifunction controller from festive-lights.com, as a replacement for some icicle lights which didn't last very long in the coastal climate we have here in the north-east of Scotland. I am still really pleased with this rope light and the controller remembers the last setting, which is great when you use them on a timer like I do.

In 2021, I thought it would be great to get another set for the back of the house. Unfortunately, festive-lights.com didn't sell this product any more, so I purchased a drum of LED rope lights and a couple of controllers from tlc-direct.co.uk. I made up the lights and it all works, but the massive downside is that these controllers do not remember the last setting they were on. I tried looking for alternatives which do have a memory function, but alas.

I then found this post, and decided I should open my controller to see if it looks similar inside. To my surprise it did, so I ordered the 1000uf 16v capacitor to replace the 47uf 16v capacitor. This evening I soldered in the new capacitor, but unfortunately it hasn't worked, as the last setting is forgotten within seconds after switching off the power. As a fix, the same article suggests to "desolder 1 side of the dropping resistor" and "solder in a 1N4148 diode with the line facing towards the IC". The problem is that with my limited knowledge, I'm unable to identify which of the three resistors on my board is the dropping resistor. Can anybody help by looking at the attached circuit board images? Also, I presume the additional diode would be positioned in series with the dropping resistor?

If all else fails, I will position an on/off switch downstream of the controller, but my preference would be to 'upgrade' the controller itself. Alternatively, could I connect the two LED rope lights in parallel to the controller which does have the memory function?

Any feedback greatly appreciated.

Thanks in advance,

John

 

[David_AVD]

The resistor near the corner marked R1 looks to be the dropping resistor. The diode would need to be a 1N4004 or 1N4007 (like the other 4 in that corner). A 1N4148 will not do for a 240V set of lights.

 

[108CAM]

Connecting the 2 strings together could cause the working power supply with the memory function to get overloaded and eventually burn out

 

[Iain]

Hi and welcome!

my preference would be to 'upgrade' the controller itself

What sort of rope-light is it? it may just be a typical 31v style LED in a rope. Do most of the lights do exactly the same thing or are they individually controlled?

Hanson sells something that can control your 2-wire fairy lights and grow to more which is the DMX2-24. There's a bunch of other info here on them:
https://auschristmaslighting.com/threads/faulty-power-units-for-31v-fairy-lights.15522/
https://auschristmaslighting.com/wiki/Controlling-2-wire-Multi-Function-LED-Strings

It depends what you want to do in the future.

 

[AberDino]

The resistor near the corner marked R1 looks to be the dropping resistor. The diode would need to be a 1N4004 or 1N4007 (like the other 4 in that corner). A 1N4148 will not do for a 240V set of lights.

Many thanks for the feedback, I will give that a go. I presume the diode would go in series with the dropping resistor, so the resistor can still do its job (but one way only)?

FYI, the other 4 diodes in that corner are 1N5399, which seems to be the 1.5A version of the 14N007 (1A), so I'll order some of those.

 

[AberDino]

Connecting the 2 strings together could cause the working power supply with the memory function to get overloaded and eventually burn out

Thought that might be the case, so thank you for the confirmation!

 

[AberDino]

Hi and welcome!


What sort of rope-light is it? it may just be a typical 31v style LED in a rope. Do most of the lights do exactly the same thing or are they individually controlled?

Hanson sells something that can control your 2-wire fairy lights and grow to more which is the DMX2-24. There's a bunch of other info here on them:
https://auschristmaslighting.com/threads/faulty-power-units-for-31v-fairy-lights.15522/
https://auschristmaslighting.com/wiki/Controlling-2-wire-Multi-Function-LED-Strings

It depends what you want to do in the future.

I'm not sure, but I think it's mains voltage (240V), see website here, which contains a link to further information and installation details. The rope light has three pins, which I guess translates to two 'feeds' and a single 'return' (2-channel), and my guess is that with the bulbs interleaved the controller can generate the various effects.

 

[David_AVD]

Many thanks for the feedback, I will give that a go. I presume the diode would go in series with the dropping resistor, so the resistor can still do its job (but one way only)?

FYI, the other 4 diodes in that corner are 1N5399, which seems to be the 1.5A version of the 14N007 (1A), so I'll order some of those.

Correct, in series with the resistor and with the cathode (band) towards the capacitor. I'm doubtful that this will solve the non memory issue though.

The series diode doesn't need to be rated for 1.5A, or even 1A for that matter. It will only see a few mA but the voltage rating required could be more than the 1N4148 can do.

 

[AberDino]

Correct, in series with the resistor and with the cathode (band) towards the capacitor. I'm doubtful that this will solve the non memory issue though.

The series diode doesn't need to be rated for 1.5A, or even 1A for that matter. It will only see a few mA but the voltage rating required could be more than the 1N4148 can do.

Diode soldered in with the band towards the capacitor, but as you suspected, it did not solve my non-memory issue .

Is there anything else I could try with this controller? If not, I might just go for a downstream switching solution and keep the controller powered on at all times.

Thanks for your help!

 

[David_AVD]

Switching the output is probably the only option unfortunately.