EK025 Triac AC Switch
Part.no: 41017062
EK025 is a switch for AC loads, built around an opto-triac and a triac. When a voltage above 1.25V is applied to the input (P1), the IR LED in the optocoupler lights up and the triac starts conducting.
The opto-triac alone cannot drive any larger loads, so it is used to provide galvanic isolation from the low voltage side and controls a larger triac.
The board includes, in addition to the opto-triac and triac, a snubber circuit (C1+R4) that allows the circuit to drive motors and other inductive loads, and a varistor (RV1) that captures and protects the triac from voltage spikes that can occur when switching a load.
The control input is designed for voltages up to approximately 5V. For higher control voltages, resistor R1 can be replaced with one of higher resistance. For 12V: 470 ohm, 24V: 1 kohm.
230VAC is present exposed in this circuit! Exercise extreme caution when connecting and using!
- Control signal: 1.25 – 5.5 VDC (12V: R1 = 470ohm, 24V: R1 = 1kohm)
- Control current (@3.3V): 10mA (max 50mA)
- Max voltage (load): 230VAC
- Max current (load): 3A (utan extra kylning)
- Dimensions: 40.64 x 30.48mm
- Mounting holes: c-c 35.56 x 25.4mm, ø2.54mm
Component list
| RefDes | Value | Qty. | Part.no. | Marking |
|---|---|---|---|---|
| AC, LOAD | Screw terminal 5mm 2-pol | 2 | 41016290 | |
| C1 | X2 capacitor 10nF 275VAC | 1 | 41015996 | 10n 275~X2 |
| P1 | Pin header 2.54mm 2-pol | 1 | 41001167 | |
| R1 | Resistor 220ohm | 1 | 40811222 | |
| R2 | Resistor 360ohm | 1 | 40811236 | |
| R3, R4 | Resistor 330ohm | 2 | 40811233 | |
| U1 | Opto triac MOC3041 | 1 | 40353041 | MOC3041 |
| U1 | Triac BTA08-600BRG | 1 | 41004528 | BTA 08-600B |
Assembly guide
Before starting assembly, check that the circuit board is free from damage and scratches. Verify that you have all the components to be installed by comparing with the component list.
It is easiest to start with the lowest components and work upwards in size. Begin by soldering the IC socket and resistors, then continue with the capacitor and varistor.
The only component on the board that is polarity sensitive is the opto-triac (U1). The remaining components only need to be placed in the correct position to function.
For smaller loads (below 3A) the triac (U2) can be mounted lying flat. The exposed surface of the package should then be soldered down against the board. For larger loads the triac can instead be mounted upright and a heatsink can be attached with a screw.
Note that the triac is NOT isolated and is directly connected to the AC voltage. Insulation between the triac and heatsink is mandatory!
Interactive assembly guide ↗
Schematic
Drawing
