Circuit dimmer light switch with Triac TIC 226 Circuit dimmer light bulb dimmer switch for led lights, diy dimmer switch for led lights (dimable type) or Incandescent bulb, a fan, a drill, soldering iron temperature and more.

Dimmers are devices used to lower the brightness of a light. By changing the voltage waveform applied to the lamp, it is possible to lower the intensity of the light output. Although variable-voltage devices are used for various purposes, the term dimmer is generally reserved for those intended to control light output from resistive incandescent, halogen, and (more recently) compact fluorescent lights (CFLs) and light-emitting diodes (LEDs). Dimmers range in size from small units the size of a light switch used for domestic lighting to high-power units used in large theatre or architectural lighting installations.

About the dimmer circuit

The circuit uses few components that together control the firing angle of the Triac, with this firing in several points of the sine signal of the network, allows applying different powers to the load.
If the trip occurs at the beginning of the half-cycle, the entire half-cycle can be conducted to the load, which will receive the maximum power. If the trip occurs at the end of the semicycle, only a portion of the energy will be conducted to the load, which will operate at minimum power.
The power adjustment occurs between these extremes.

The DIAC, or Diode for Alternating Current, is a bidirectional trigger, or diode that conducts current only after the trigger voltage is reached, and stops conducting when the electric current drops below a characteristic value, called the cut-off current. This behavior is the same in both directions of current conduction. The tripping voltage is around 30 volts for most of these devices. This behavior is somewhat similar, but more precisely controlled and occurring at a lower value, to the behavior of a neon lamp.

About Snubber (C2/R2)
Snubbers are small circuits inserted in power static converters, whose function is to control the effects produced by the intrinsic reactance of the circuit. Snubbers can dampen oscillations, control the rate of change of voltage and/or current, and clamp overvoltages.

Schematic dimmer light switch with Triac

PCB for dimmer light switch with Triac

Attention: how to install dimmer switch circuit working directly with the high voltage network, risk of electric shock.

• Use a small heatsink in the Triac.
• You can use an incandescent bulb or LED bulb (dimmable), a fan, speed a drill, soldering iron temperature and more.
• You must use a fuse to protect the circuit, this fuse will have a nominal value 30% higher than the load to which it will be connected.
• Also, optionally a switch can be used to turn off the circuit
• The Triac to be used must be according to the load with at least 30% tolerance to the current. Relating to the voltage these should be at least 30% of the peak voltage where it is installed. The VPP is 155V in 110V and 311V in 220V.
• You may need to change capacitor C1 to achieve full operation. Values between 69nF and 220nF can be tested.
• Various TRIACs can be used according to your needs, only adapting the voltage and current you need. Common in market are Bta16-600, Bta16-700, Bta16-800, Bta41-600, Bta10-700, Bta12-700, T410-600, Bta24-800, Bt136-600, Tic226, TIC236, TIC246. Just watch out for the suffixes and codes of each Thyristor because they tell you what current and what maximum voltage they support.
• The bulb used be the dimmable type (dimmable, dimmable, DIM, attenuators, adjustable). Dimmer switches for led lights (dimmable) and Incandescent bulb.

Part list

Download the PDF board files for this assembly. (Updated files, includes Gerber and panel with 4 plates)

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Mirror

• Download PDF datasheet PDF Triac TIC226 TIC226D, TIC226M, TIC226S, TIC226N
• Download PDF datasheet PDF DIAC DB3, DB4, SMDB3
• Download PDF datasheet PDF Triac  T1610, T1635, T1650, BTA16, BTB16 , Bta16-600
• Download PDF datasheet PDF Triac  BTA40, BTA41, BTB41, Bta41-600
• Download PDF datasheet PDF Triac  Bta10-700, BTA10, BTB10, T1035, T1050
• Download PDF datasheet PDF Triac Bta12-700, BTA12, BTB12, T1205, T1210, T1235, T1250
• Download PDF datasheet Triac Bta24-800, BTA24, BTB24, T25
• Download PDF datasheet PDF Triac Bt136-600