Triac CV LED Driver Technology

How Triac mains dimmable constant voltage drivers let 12V and 24V LED strip be dimmed from standard wall dimmers or push switches, and how to choose the right one.

Triac mains dimmable constant voltage LED drivers

Overview

What is a Triac CV LED driver?

A Triac dimmable constant voltage (CV) driver is a 12V or 24V DC LED power supply that works with a standard mains phase-cut dimmer. The dimmer is wired in the live feed in place of a light switch and cuts part of each mains half-cycle. The driver reads what remains and dims the LED strip, linear light or signage connected to its output, with no extra control wiring.

Our Triac CV range from Snappy, Lifud and LTECH covers 10W to 300W at 12V or 24V, in compact and slim linear cases. The drivers work with most leading and trailing edge dimmers for smooth, flicker-free dimming, and LTECH models add mains push dimming, dimming down to 0.1% and a dual-channel CCT version for tuneable white strip.

Dims 12V and 24V LED strip from a standard wall dimmer
No extra control wiring: ideal for retrofit and residential projects
Flicker-free PWM dimming with stable colour
Mains push dimming on LTECH models
Dual-channel CCT model for tuneable white strip

Triac CV range at a glance

Brands: Snappy, Lifud, LTECH
Output voltage: 12V or 24VDC
Power: 10W – 300W
Input: 220-240VAC mains
Dimmers: Leading and trailing edge
Other inputs: Mains push dimming
Dimming: 0–100%, flicker free
Colour: Single colour or CCT

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The technology

How Triac CV dimming works

A Triac (phase-cut) dimmer removes part of each mains half-cycle: a leading edge dimmer cuts the start, a trailing edge dimmer cuts the end. The driver measures the remaining conduction angle to work out the dimming level.

It then produces a steady 12V or 24V output and dims the strip by pulse width modulation (PWM), switching the output on and off at high frequency. The lower the dimmer setting, the shorter the on-time, while the strip's colour stays consistent.

On drivers with push dimming, a mains push switch on a separate terminal does the same job: a short press switches on or off, and a long press dims.

Simplified illustration: the Triac dimmer or push switch sets the level, and the driver dims its 24V output by varying the PWM on-time.

Control options

Leading edge, trailing edge and push dimming

Our Triac CV drivers work with both dimmer types, and LTECH models also accept a simple push switch.

Feature	Leading edge (RL)	Trailing edge (RC / ELV)	Push dimming
How it controls	Cuts the start of each half-cycle	Cuts the end of each half-cycle	Momentary mains push switch
Control	Rotary or slide dimmer	Rotary or slide dimmer	Short press on/off, long press to dim
Character	Abrupt switching, can buzz	Gentle switching, usually quieter	No dimmer needed, level remembered
Best for	Existing leading edge circuits	New LED installations	Simple, low-cost local control
Our drivers	All Triac CV series	All Triac CV series	LTECH LM-G1T2 and LM-G2T2

For constant current models, see Triac LED driver technology.

Our range

Triac CV drivers compared

Choose the voltage to match the strip, the power to cover the load, and the control features you need.

Series	Output	Power	Format	Dimming
Snappy SP	12V / 24V (200W, 300W: 24V)	10 – 300W	Compact	Triac leading / trailing edge
Snappy SL Linear	12V / 24V	75 – 150W	Slim linear	Triac leading / trailing edge
Lifud LF-GAT	24V	75W, 150W	Linear	Leading / trailing edge
LTECH LM-36-G1T2	12V / 24V	36W	Linear	Triac / ELV + push
LTECH LM-75-G1T2	12V / 24V	75W	Linear	Triac / ELV + push
LTECH LM-150-G1T2	12V / 24V	150W	Linear	Triac / ELV, soft-on / fade
LTECH LM-75-G2T2	12V / 24V, 2 channels	75W	Linear	Triac / ELV + push DIM / CCT

Benefits

Advantages of Triac CV LED drivers

Why Triac dimming is a popular way to control LED strip in homes, hospitality and retrofit projects.

No extra wiring

The dimmer replaces the light switch in the existing live feed, with no separate control cables.

Smooth PWM dimming

Flicker-free 0–100% dimming that keeps the strip's colour consistent, down to 0.1% on LTECH models.

Push dimming

Use a simple retractive push switch instead of a dimmer, with the last level remembered.

Tuneable white

The dual-channel LM-75-G2T2 adjusts brightness and colour temperature from a dimmer or push switch.

Ideal for retrofit

Add dimmable LED strip to circuits that already have phase-cut dimmers, with no rewiring.

Up to 300W

From compact 10W drivers for cabinets to 300W units for long strip runs.

Selection & set-up

Choosing and installing a Triac CV driver

Match the voltage: use a 12V driver for 12V strip and a 24V driver for 24V strip.
Size the power: add up the strip load (W/m × length) and allow at least 20% headroom.
Use the right load: Triac CV drivers suit resistor-limited LED strip; check before connecting constant current fixtures such as MR16 lamps.
Use an LED-rated dimmer: keep the total driver load within its LED rating; trailing edge usually gives the smoothest results.
Set the minimum level: if the dimmer has a minimum-level adjustment, set it so the strip stays stable at the bottom of the range.
Limit voltage drop: on long runs, feed the strip from both ends or from several points.

Related technology and products

Compare other dimming methods and complete the installation:

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12 / 24V

Output voltage

10–300W

Power range

0.1%

Dimming depth (LTECH)

Extra control wires

Where Triac CV drivers are used

Wherever LED strip needs to be dimmed from a standard wall dimmer or push switch.

Residential

Kitchen, cove, staircase and bedroom strip on existing dimmers.

Hospitality

Bar, back-light and mood lighting in restaurants and hotels.

Retail

Shelf and display strip in shops and showrooms.

Retrofit

LED strip upgrades on circuits with phase-cut dimmers.

Furniture

Cabinet, wardrobe and display-case lighting.

Meeting rooms

Cove and feature strip dimmed for presentations.

FAQ

Triac CV driver questions

A Triac dimmable constant voltage (CV) driver is a 12V or 24V DC LED power supply that works with a standard mains phase-cut wall dimmer. The dimmer cuts part of each mains half-cycle, and the driver reads what remains and dims the LED strip connected to its output, with no extra control wiring.

The driver keeps its output at 12V or 24V and dims by pulse width modulation (PWM), switching the output on and off at high frequency. The setting of the Triac dimmer controls how long the output is on in each cycle, which keeps the colour of the strip consistent as it dims.

Push dimming uses a standard mains retractive push switch instead of a dimmer. A short press switches the light on or off and a long press dims up or down, with the last level remembered. Drivers such as the LTECH LM-G1T2 series accept either a Triac dimmer or a push switch.

Triac CV drivers are designed for resistor current-limited loads such as standard 12V and 24V LED strip. Fixtures with built-in constant current electronics, such as MR16 lamps or constant current strip, can draw a much higher inrush current and trip the driver's overload protection, so check compatibility before connecting them.

Match the driver output voltage to the strip, add up the strip load in watts (watts per metre multiplied by length) and choose a driver rated at least 20% above that total. Also check the total driver load sits within the Triac dimmer's LED rating.

Triac CV LED Driver Technology