BT136 600E TRIAC : Pin Configuration & Its Applications

In BT136 600E TRIAC, the term TRIAC stands for “TRIode for AC” or Alternating Current. This is a three-terminal, five-layer power semiconductor device. It includes a controlled SCR pair which is connected in opposite parallel methods on the similar IC. TRIAC conducts the flow of current in two directions so it is called a bidirectional device.

There are different types of TRIACs available in the market along with BT136 600E TRIAC like BT137, BT138, BT138, etc. This article discusses an overview of BT136 600E TRIAC which includes its pinout, specifications, working, and its applications.

What is BT136 600E TRIAC?

The BT136 TRIAC uses maximum terminal current like 4A and less gate threshold voltage so it can be driven through digital circuits. TRIACs are switching devices with bi-directional and they are frequently used in switching AC-based applications. Thus, if you are looking to control an AC load that uses below 6A through a microprocessor or microcontroller then BT136 600E TRIAC is suitable for your application.

A special semiconductor device like TRIAC replaces the SCR structure to achieve bidirectional control. This is a bidirectional switching device, used to control the AC power accurately & efficiently. So these are frequently used in AC circuits, motor speed controllers, light dimmers, pressure control systems & other AC control devices.

Pin Configuration

The pin configuration of BT136 600E TRIAC includes the following.

BT136 TRIAC Pin Configuration
BT136 TRIAC Pin Configuration
  • Pin1 (Main Terminal1): This terminal is allied to the neutral/phase of AC mains
  • Pin2 (Main Terminal2): This terminal is allied to neutral or phase of AC mains
  • Pin3 (Gate): This terminal is used to activate the silicon controlled rectifier

Features & Specifications

The features and specifications of BT136 600E TRIAC include the following.

  • The maximum supply current through the terminal is 4A
  • The voltage at the On-state gate is 1.4V
  • Gate trigger current is 10mA
  • The maximum terminal voltage is 600 V
  • Holding current is 2.2mA
  • The latching current is 4mA
  • The available package is To-220
  • Equivalent BT136 600E TRIAC is BTA08-600B whereas an alternate BT136 600E TRIACs are BTA16, Q4008, BT139 and BT169.

Precautions while using a BT136 600E TRIAC

The following precautions need to take while using a BT136 600E TRIAC like the following.

The designing of TRIAC circuit which deals with AC voltage must be done very carefully. The circuits using TRIAC face some effect known as Rate Effect because this effect will occur once the TRIAC device is switching normally & an abrupt high voltage takes place at any terminal to harm the TRIAC. So it can be neglected through a snubber circuit.

Likewise, there is an additional effect namely the backlash effect which takes place because of the accumulated capacitance among the two terminals of TRIAC like MT1 & MT2. So due to this reason, the TRIAC will not be switched ON even if the voltage at the gate terminal is applied. So, this difficulty can be resolved by supplying a resistance within series to the capacitance for discharge.

Once the output AC voltage controls for speed control or dimmer applications, a technique like Zero crossing is suggested always. The TRIAC within switching circuits is simply subjected to EMI interference & to harmonics thus it must be isolated through other digital electronics. There is the possibility of backward current once the TRIAC controls inductive loads; consequently, an alternate discharge lane has to be given for the inrush current from load to drain.

AC Power Control Circuit using BT136 600E TRIAC

The circuit diagram of AC power control with BT136 600E TRIAC is shown below.

The TRIAC is a perfect power electronics switch, used in switching applications as it controls the current flow on both cycles in an alternating signal. The main benefit of this is not expensive as compared to the back-to-back thyristor circuit. If you want to control up to 600V of voltage & 4A of current then the above Triac & back-to-back thyristor is recommended to work the circuit properly.

AC Power Control Circuit with BT136
AC Power Control Circuit with BT136

High voltage devices controlling with power electronics device which is isolated optically provides voltage control benefits. Here, the simple BT136 TRIAC circuit, as well as MOC3021 Optocoupler, is capable of controlling maximum voltage devices using a microcontroller.

For instance, an Arduino board is used to control high voltage devices or bulb-like 230v or 220v. So this circuit can also be used for dimming & the application of speed controlling with PWM signal using Arduino. When the TRIAC includes a valve in bidirectional, then this circuit is used mainly for AC& DC applications.

The required components to build this circuit are; R1=330 Ohms. R2=360 Ohms, R3=470 Ohms, R4= 39 Ohms, C1 = 50nf or 0.05uf, 250V or 400V, C2=10nf or 0.01uf, 250V or 400V, U1=MOC3021 or 3031 or 3051, U2 is 6-pin IC Socket, BT136 TRIAC, lamp with 100W 230V 4 cm×10 cm PCB, flexible wire, soldering iron, metal wire, 2-pin PBT connector, holder for lamp, etc.

The TRIAC works mainly in two conditions like during ON and during OFF. In the first condition, the voltage like 3.3 or 5 is used through a microcontroller to the MOC3021 optocoupler devices which includes GaAs IR emitting diodes on both the pin-1 & pin-2.

This kind of diode generates IR light & makes active the light-activated Si bilateral switch which is coupled optically on both the pins like 4 & 6 so that it permits current supply in between them. So this current supply gives current at the GATE terminal toward the TRIAC gate’s pin3. So, TRIAC will conduct the major current supply in between two pins like MT1 & MT2.

In the second condition, when there is no voltage is given in between the optocoupler’s two pins like pin1 & pin2, then both the pins like 4 & 6 will perform like opened switch so there is no flow of current in between them, because there is no current at GATE to TRIAC and it ends conducting.


The advantages of TRIAC include the following.

  • When the Ve & -Ve polarity voltages are given at the gate terminal then it will be activated.
  • It can function & control the AC waveforms in both half cycles.
  • A thyristor uses a single large size heat sink as compared to the anti-parallel design based on two heat sinks in small size. So TRIAC conserves both cost and space within AC power applications.
  • In direct current applications, silicon-controlled rectifiers are mandatory to connect through a parallel diode for protecting from reverse voltage. However, the TRIAC may function without using a diode but a secure breakdown is achievable in any direction.


The disadvantages of TRIAC include the following.

  • More care needs to be taken while choosing a gate triggers circuit because a TRIAC device activates in both the biased conditions.
  • These are less reliable as compared to thyristors.
  • As compared to thyristors, these have less dv/dt rating
  • The switching frequencies of TRIACs are extremely small.

Where to use/Applications

The applications of TRIAC include the following.

  • Because of the bidirectional control of alternating current, these components are used as different controllers for AC, fan, heater, static switch with three positions, triggering devices for silicon controlled rectifiers, light dimmers, etc.
  • Triac is used as a switch
  • It is used as a High power switch
  • Used to control phase
  • Strode lights
  • Speed control of AC motor
  • Used in circuits of noise coupling
  • AC loads controlling with MPU or MCU
  • Power control of AC or DC

Know more about DIAC and TRIAC.

Thus, this is all about an overview of the BT136 600E TRIAC datasheet like its pin diagram, features, circuit working, advantages, disadvantages, and applications. Here is a question for you, what is the difference between TRIAC and DIAC?