Yieldbuddy Store

Welcome! Jan 15, 2015: More AC Boards available!

AC Dimmer Board 00001 Can$20.00


Recently updated!  Revision 1.3:  Smaller, Wider/Thicker Traces, Better Isolation, Heatsink

  • Dimmer Board for selecting any voltage between 0 VAC - 120 VAC  or  0 VAC - 240 VAC

  • Zero-Cross detection (with zero/cross output pin)
  • Programmable Atmel ATtiny85 via 6-pin ICSP header
  • Compatible with any Arduino!
  • Can be controlled using voltage [ 0.55V - 2.77V] or by using PWM
  • Available for 50Hz or 60Hz  (But can be reprogrammed using ICSP header).
  • 120V or 240V
  • LED 'AC ON' indicator
  • 4-Corner Mounting Holes
  • Triac rated for:
    • Peak Non Rep Surge Current Itsm 50Hz:   140A
    • Peak Repetitive Off-State Voltage, Vdrm:   600V
    • On State RMS Current IT(rms): 16A

Controls the amount of dimming based on an input voltage on the CTRL pin
or a Pulse Width Modulation (PWM) signal.

Choose the mode by using the 'Mode' pin:

Ground = Voltage Mode
3.3V / 5V = PWM Mode

Using Voltage Mode and supplying voltage to the 'CTRL' pin:

0 - 0.65V:

100% Dim (Fully OFF)

0.65V - 2.65V:

100% - 0% Dim

2.65V - 5V:

0% Dim (Fully ON)

Using PWM Mode and supplying PWM signal to the 'PWM' pin:

0 - 5%   

100% Dim (Fully OFF)

analogWrite(0) to analogWrite(15)


100% - 0% Dim 

analogWrite(15) to analogWrite(90)

Greater than 40%: 

0% Dim (Fully ON) 

analogWrite(90) to analogWrite(255)

Note that for Normally OFF some applications require a resistor (tested with 65K) between CTRL and Ground, while directly powering from an Arduino does not.

  • 5V connects to '+' pin on the ICSP header (marked on PCB)
  • Ground connects to '-' on the ICSP header (marked on PCB)

Example uses: Control the speed of a fan, drill, motor, etc.  Dim lights.  Control temperature using a heater. Brewing beer. Maintaining a set-point using AC, etc.

While high voltage systems are interesting experimentally, they can be dangerous, and if not treated with care, respect and intelligence, they can result in a fatal injury.