The phrase gets used for the power that reaches the LED and for the signal that tells it how bright to be. They are unrelated decisions, and confusing them is the most common reason a lighting package arrives on site unable to do what the drawings promised.
A 24V tape run dimmed over DALI is low voltage twice over — for two entirely different reasons. Getting the vocabulary straight makes every later conversation shorter.
Every LED ultimately runs on low-voltage DC. The real architectural question is where the driver lives: inside each fixture, fed from a 120V circuit, or as a separate remote unit feeding low-voltage fixtures. That choice sets efficiency, reliability, replaceability and which dimming protocols are even available to you.
The control signal is a separate wire and a separate decision. It can be analog (0-10V) or digital (DALI), and the same fixture is often available either way.
A remote driver converts mains to low-voltage DC. Safe to handle, required for wet and landscape locations, and what makes trimless details, tape and magnetic track physically possible. The driver sits somewhere cool and accessible instead of cooking beside the LED.
A separate low-voltage pair tells the driver what level to run at. Either an analog 0–10 volt level shared by a whole zone, or a digital bus where every driver has its own address.
Neither is better. They fail differently, cost differently, and belong in different parts of the same house.
| Factor | Line voltage — integrated driver | Low voltage — remote driver |
|---|---|---|
| Driver location | Built into each fixture or bulb | Separate remote unit feeding several fixtures |
| Upfront cost | Lower — fewer parts, simple retrofit | Higher — driver, low-voltage wiring, design time |
| Install effort | Wires to existing 120V circuits | Driver sizing, voltage-drop and wire-gauge design |
| Long runs | Better — no voltage-drop penalty | Worse unless wire is upsized (ten times the current at 12V) |
| Reliability | Driver bakes beside the hot LED board | Driver mounted somewhere cool — both last longer |
| On failure | Replace the whole fixture | Replace the driver alone; keep the fixtures |
| Failure isolation | Fails one fixture at a time | A shared driver takes its whole group dark |
| Wet & landscape | 120V at the fixture | 12/24V — low shock risk, and usually required |
| Dimming available | Phase-cut (TRIAC / ELV) | Phase-cut, 0-10V or DALI, depending on driver |
| Form factor | Standard fixture and lamp sizes | Tiny apertures, coves, tape, trimless detail |
A second split inside “low voltage”, decided by the fixture rather than by the control system. Only one of these is actually the “12/24V” everyone means.
Holds a fixed output voltage — 12V or 24V DC — while the load draws what it needs. Fixtures have onboard current limiting and wire in parallel.
Holds a fixed output current — 350, 700 or 1050 mA — while the output voltage floats to match the LEDs, often well above 24V. Fixtures wire in series.
Once a dimmable low-voltage design is chosen, the driver has to speak something. These are the two that matter, and the choice shapes wiring, flexibility and what your control system must support.
A control pair carries a DC voltage. 10V is full output, around 1V is minimum. Everything on that pair dims together as one zone. Cheap, robust, essentially wire-and-go — and not addressable, so re-zoning means re-wiring.
How 0-10V worksA two-wire digital bus where every driver has its own address. Groups and scenes live in software, the bus reports faults back, and tunable white is native. Higher component cost and a real commissioning step.
How DALI works| Dimension | 0-10V (analog) | DALI / DALI-2 (digital) |
|---|---|---|
| Addressability | None — one level per control pair | Per fixture; every driver has an address |
| Capacity per line | One level; more zones means more wiring | 64 addresses, 16 groups, 16 scenes |
| Wiring | Circuit plus a separate polarity-sensitive pair | Two-wire bus, star or tree; polarity-free |
| Feedback | One-way; no status | Two-way — level, status and fault reporting |
| Tunable white / colour | Awkward; needs extra channels | Native (DT8) |
| Dimming curve | Smooth, but low end varies by driver | Standardised logarithmic curve; repeatable |
| Commissioning | Wire and go | Software addressing, a real setup step |
| Best fit | Well-defined zones on a tight budget | Granular scenes, colour, feedback, evolving installs |
Low-end smoothness and flicker depend on the specific driver, not the protocol alone. Specify quality drivers either way.
This is where residential projects come unstuck. The protocol is only half the decision — the wall keypads and hub have to be able to drive it.
Within Lutron's residential range, Caséta is a phase-cut system: natively it drives neither 0-10V nor DALI. RadioRA 3 adds 0-10V through a per-zone dimming module, but still not DALI. Native DALI means stepping up to HomeWorks — which is a large jump for what is often a handful of zones.
That constraint is worth knowing before the fixtures are specified, not after.
We deploy a DALI-to-MQTT controller that sits between the lighting and the control system, so the keypads you already wanted can drive the protocol the fixtures actually use.
It talks to the Lutron Smart Bridge PRO over LEAP — Lutron’s own local API, certificate-authenticated over TLS on your network. A Pico press is read directly from the bridge and turned into a command on the DALI bus. No cloud, and no smart-home hub in the middle.
Specify the PRO bridge. Caséta exposes LEAP integration on the Smart Bridge PRO (L-BDGPRO2) — not the standard Smart Bridge. On RadioRA 3 it is the RR-PROC3 processor. Getting this wrong is a cheap mistake to make and an annoying one to discover on site.
Bridged control is excellent for scene recall, set-level and on/off. Native phase-cut or a native 0-10V module still give the smoothest continuous hold-to-dim ramps.
Tell us the rooms, the ceilings and what you want the light to do. The protocol decision usually answers itself once those three are on the table.