LED driver, voltage smoothing

[Wotname]

Originally Posted by GILow

Well, I can’t imagine what else it would be. Happens with any variation of load on the house battery bank.

Originally Posted by GILow

It’s not wiring.

The lighting is on its own separate branch, not even slightly related to the equipment that causes the flicker.

EMI?????

[GILow]

Originally Posted by Wotname

EMI?????

Not impossible, but I’d be surprised, given the sorts of tiny currents that affect them.

[Wotname]

What exactly do you mean when you say flicker?
Do they get brighter or dimer or go almost off?
Once or multiple times per event?
All the LED strips or some or one?
Every time there is a change in current draw on the boat or only on some loads?

Have you tried an independent voltage source to drive the LED?

[s/v Jedi]

I don’t think it’s a good idea to use any of these eBay/Amazon gadgets while DX’ing on the amateur bands. I don’t even know if a professional marine product is that spectrally clean.

Anyway, here are the professional marine versions... the smallest one 12v/12v at 100W 9A lists for 66 Euros: https://www.victronenergy.com/upload...50-400W-EN.pdf

[GILow]

Originally Posted by Wotname

What exactly do you mean when you say flicker?
Do they get brighter or dimer or go almost off?
Once or multiple times per event?
All the LED strips or some or one?
Every time there is a change in current draw on the boat or only on some loads?

Have you tried an independent voltage source to drive the LED?

Flicker as in detectable (and annoying) variation in light level with practically any change of electrical status in the boat.

So, water pump causes the lighting to “tremble”, diesel heater pump causes metronomic pulsing.

Doesn’t matter how big or small the load. Same effect from the 15 amp toilet as switching on a 2.5 amp USB port.

I’ve read about this behaviour somewhere before, but I can’t find it. But I remember the need for a really smooth power supply, hence my post. SVJedi seems to have experienced the same thing, if I read his post correctly.

Edit: and whatever it is that Webasto heaters do at shutdown causes the lighting to go completely nuts for about five seconds.

[conachair]

Originally Posted by GILow

It’s not wiring.

The lighting is on its own separate branch, not even slightly related to the equipment that causes the flicker.

How can it be voltage then? Unless you have a tiny battery?

[Bill O]

Originally Posted by GILow

Oh dear... how long did they last?

Mine are hidden behind a timber trim strip and shine upwards against the ceiling. They look lovely and I really want them to keep working?

Our dimmers (for this round of LEDs)(linked previously) have been in for > 4 years and no problems w/them. I liked these because they were small/sleek and one could hide them easily.

We have similar up lights behind trim and we like that indirect lighting.

[s/v Jedi]

Originally Posted by GILow

Flicker as in detectable (and annoying) variation in light level with practically any change of electrical status in the boat.

So, water pump causes the lighting to “tremble”, diesel heater pump causes metronomic pulsing.

Doesn’t matter how big or small the load. Same effect from the 15 amp toilet as switching on a 2.5 amp USB port.

I’ve read about this behaviour somewhere before, but I can’t find it. But I remember the need for a really smooth power supply, hence my post. SVJedi seems to have experienced the same thing, if I read his post correctly.

Edit: and whatever it is that Webasto heaters do at shutdown causes the lighting to go completely nuts for about five seconds.

My main reason is that I don’t want to burn out LEDs while charging. Flickering that we noticed was mainly caused by cheap dimmers. I have tested the small modules I first linked to and they hold 12.0V even when I change input all the way between 3V - 30V. The XL6009 used in these is the industry standard and efficiency is claimed to be over 90% which is very good. Switching frequency is 400kHz which is very good as well. At $12 for two you have nothing to lose. I bought these to be used inside armatures that previously held 12V ballast loads and fluorescent lights.

I have switched to these LEDs which are waterproof and easier to use, with much better adhesive as well: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Wotname]

Originally Posted by GILow

Flicker as in detectable (and annoying) variation in light level with practically any change of electrical status in the boat.

So, water pump causes the lighting to “tremble”, diesel heater pump causes metronomic pulsing.

Doesn’t matter how big or small the load. Same effect from the 15 amp toilet as switching on a 2.5 amp USB port.

I’ve read about this behaviour somewhere before, but I can’t find it. But I remember the need for a really smooth power supply, hence my post. SVJedi seems to have experienced the same thing, if I read his post correctly.

Edit: and whatever it is that Webasto heaters do at shutdown causes the lighting to go completely nuts for about five seconds.

Very curious and the Jedi solution sounds like a good place to start.

Prolly better than a big parallel capacitor and some ferrite beads .

[GILow]

Originally Posted by conachair

How can it be voltage then? Unless you have a tiny battery?

Buggered if I know... I figure it is really minuscule voltage variations.

I mean, 6 Trojan T105s is not a tiny battery bank, at least I don’t think so.

[GILow]

Originally Posted by Wotname

Prolly better than a big parallel capacitor and some ferrite beads .

How about a big capacitor and some prayer beads?

[s/v Jedi]

Originally Posted by Wotname

Very curious and the Jedi solution sounds like a good place to start.

Prolly better than a big parallel capacitor and some ferrite beads .

The Victron’s I linked are even better because they are galvanically isolated so it would be very hard to get their output to flicker

I’m pretty sure the $6 gadgets will work for a single 1A LED strip. They come with tiny heatsinks but mine did not come with an adhesive to stick those on. I think I used some heatsink paste that I had and a drop of superglue at the edge for security. This is tinkering diy level, just try them, feel how hot they run and how much to load them. If one just wants to buy something and be done with it then the Victron is the best solution. You may even buy a bigger model and use it for other stuff that wants a stable 12V as well (wifi routers, switches etc.)

[wingless]

Originally Posted by wingless

The preferred method for LED operation is to drive them using a constant current.

When that method is properly implemented it ignores voltage variations, maintaining a constant brightness output, regardless of input voltage, until the input voltage drops below the lower operational limit.

There are simple and more complex LED drive circuits available.

Here are simple constant current circuits that eliminates brightness fluctuations from voltage variations.

[Lake-Effect]

Originally Posted by GILow

Flicker as in detectable (and annoying) variation in light level with practically any change of electrical status in the boat.

So, water pump causes the lighting to “tremble”, diesel heater pump causes metronomic pulsing.

Doesn’t matter how big or small the load. Same effect from the 15 amp toilet as switching on a 2.5 amp USB port.

I’ve read about this behaviour somewhere before, but I can’t find it. But I remember the need for a really smooth power supply, hence my post. SVJedi seems to have experienced the same thing, if I read his post correctly.

Edit: and whatever it is that Webasto heaters do at shutdown causes the lighting to go completely nuts for about five seconds.

A boat battery is a near-ideal "smooth" power supply.

When you did your voltage measurements, did you only look for drops across the positive lines? Drops can occur across the return (negative) too.

One thing that sticks out is that many of the loads are physical... any chance the flicker is due to vibration or shaking?

Finally, a "flicker" is going to be too fast to register on just about all meters. Can you borrow an oscilloscope? The new generation of cheap digital scopes can capture and display fast-changing events.

[j.g.evans]

Some readers suggest powering the LEDs from a constant current source and that is a good idea. Shorten your string and power the remaining LEDs from one of the suggested circuits. Removing 1 LED should drop the required voltage about 3 Volts which is about what a constant current circuit would require.
If you want to stay with 12V them go to mpja.com and get a DC-DC converter such as their 35075 PS. Put capacitors across the terminal too to prevent interference with your radios.