LED Flicker in NSW & QLD Solved: The Definitive Guide to Zellweger Ripple Control and How to Fix It for Good

You are here because you searched for how to fix led lights flickering or you were provided this link as a way to solve your led lights flickering issue. You also likely live in Australia in NSW or QLD.

If your lights in NSW/QLD flicker at the same times each day, you’re almost certainly seeing ripple-control (Zellweger) tones from the electricity network, not “faulty” fittings.

There are only a few robust ways out of this, as explained below - with more detail in the complete article below these summaries.

2025 Low Risk Practical Guidance

Don’t fight the physics with ever more filters on marginal products.

In ripple areas, avoid phase-dimming LED lamps (bulbs/ globes), and instead either:

1. run them as switch-only, or
2. switch to ripple-immune modules (DALI-2 / RippleShield) or LED strip + DC-side PWM.

For readers trying to solve flicker today - the Detail

If your LED lights in NSW or Queensland flicker, pulse, or “breathe” at roughly the same times each evening, and especially if it gets worse the more you dim them, you are almost certainly running into ripple-control signalling, also known as Zellweger off-peak tones.

These are high-frequency signals (typically around 750 Hz or 1050 Hz) that the electricity networks superimpose on the 230 V supply to switch off-peak hot-water, street lights and other controlled loads.

For decades, those tones didn’t visibly bother anyone. Incandescent and halogen lamps appeared to ignored them - meaning its been present since the 50's you as a home user dimming never noticed it.

But modern LED lamps and many electronic phase dimmers don’t.

Their electronics can “see” the injected tone in the waveform and translate it into visible flicker, sudden brightness jumps, or lights that never quite turn fully off. Field reports from electricians in NSW/QLD, plus manufacturer and driver-vendor blogs, all tell the same story: phase-dimming LED lamps on a ripple-affected network is asking for trouble.

Officially, the problem is recognised.

Federal lighting policy papers describe LED lamps flickering for a few minutes several times a day when ripple signals are sent to control off-peak loads, particularly in New South Wales and Queensland.

They note that “rectification and workarounds” are being handled by networks and lighting suppliers, and that a Ripple Control Working Group – with Lighting Council Australia, Energy Networks Australia, the University of Wollongong and others – was formed to explore solutions.

But as of 2025, no single national “this is the fix” directive has emerged.

Despite early cross-industry discussions, the combination of cost, legacy network design and regulatory priorities has resulted in Zellweger/ripple-induced LED flicker being treated as an accepted nuisance, to be managed at the installation level by lighting suppliers and electricians, rather than eliminated or comprehensively standardised at the network or regulatory level.

The solutions detailed essentially means the home owners or facility owner needs to pay more to eliminate flickering.

Whether that be choosing an often prohibitive DALI2 solution - especially at that late stage of a project that flickering is 'discovered'; RippleShield downlights swaps or changing lighting control hardware for previously designated dimmable fixtures,  to switching only.

For practitioners on the ground, that means being brutally realistic about what does and doesn’t work.

Phase-dimming LED lamps (globes) in ripple suburbs is a high-risk design choice.

Any fitting that relies on a mains phase-cut dimmer plus a retrofit LED lamp (globe or bulb) is directly exposed to whatever the network injects onto the line. Whirlpool threads, AusElectricians posts and experience from the field show that changing dimmer brand, lamp brand or adding a generic “LED-rated” dimmer often only shifts the symptoms rather than removing them.

In these areas, the safest recommendation is often to stop dimming those fittings entirely.

Run them switch-only, and if necessary, adjust the lamp wattage and beam spread to get an acceptable light level at full power.

In commercial hospitality spaces, that may mean accepting that these circuits are for decorative / ambience rather than your primary task-lighting that must meet code-mandated lux levels, and designing your lighting scheme accordingly with non-ripple-sensitive circuits doing the heavy lifting.

Move to purpose-designed, ripple-immune fittings for dimming not dimmable lamps.

Where dimming is non-negotiable, the more robust approach is to abandon the any lamp on any dimmer idea and move to systems where the driver is engineered to cope with a dirty mains waveform.

Note that the example provided below ARE NOT LED lamps ( globes and bulbs which are twisted / fitted into batten holders - these are the primary type of light source which cannot be reliably dimmed without flickering in affected areas).

First options is to use DALI2 LED drivers, where dimming is handled in the driver logic rather than by chopping the mains as per the phase dimmed technology.

The challenge is that the DALI2 driver and fixture will most certainly cost more AND to operate this specialised equipment, cabling which likely has not been installed, and system programming by dedicated DALI programming engineers is needed.

The second option is SAL’s RippleShield / SFI systems, which pair specific downlights (e.g. UNIFIT and Ecogem SFI variants) with a matched RippleShield/SFI dimmer and advertise elimination of nuisance ripple-induced flicker between 750–1050 Hz, the exact tone range used for off-peak control in NSW and SE QLD

The advantage RippleShield has over DALI 2 is that there is NO special cabling needed, in fact electricians change nothing in their cabling, unlike the DALI2 solution above; But there is a small range of downlights shapes and light output to choose from. These would be suitable for most people most of the time, but for specialised lights angles and bespoke installations a suitable option may be challenging to find.

 
In other words, choose a system that has been tested as a system, rather than gambling on random lamp/dimmer combinations against a hostile network environment.

Use LED strip with DC-side PWM dimming where possible

For feature lighting, coves, back-lighting and similar, LED strip with a non-dimmable driver and a PWM controller on the DC side is inherently less sensitive to small disturbances on the 230 V supply.

The AC driver produces DC, and the PWM dimmer works on that DC feed; the mains waveform games are mostly handled inside the driver and upstream of the actual modulation of light output.

Industry guides describe this as the simplest and most robust way to dim constant-voltage strip, separating mains disturbances from the dimming method.

Treat ripple filters as a tool, not a silver bullet.

Yes, Zellweger / ripple filters from Gayrad, Thor and others can help. They are specifically marketed to attenuate 750/1050 Hz ripple used for off-peak control and can reduce symptoms across a whole circuit.

But the fine print matters:

Gayrad openly state their filters do not completely block the tone, but reduce it “by 1/30th of the original level”. gayrad.com.au

Thor describe their DRM750/DRM1050 units as designed to reduce or cancel the effects of ripple, not as a guaranteed 100% cure under every load combination. thortechnologies.com.au

Real-world user reports show cases where installing a ripple filter did not fully stop LED flicker, and the eventual fix was changing the fittings or control method instead.

The practical takeaway you can give a client is: filters can help and are sometimes enough – but they cannot be guaranteed to solve every LED/dimmer/ripple combination. They’re one part of the toolkit, not the foundation of your design.

In 2025, there is still no neat, official one-page directive from government, Lighting Council or the DNSPs that magically solves ripple-induced LED flicker.

Instead, the pattern in the standards, policy documents and field experience is clear:

1. Ripple/Zellweger tones are not going away.
2. Phase-dimming LED lamps on those networks is inherently fragile.
3. Robust solutions come from changing the control architecture from “any lamp on any dimmer” to switch-only where appropriate, or to dedicated ripple-immune drivers and DC-side dimming where you truly need smooth, reliable control.