Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [triac]

A TRIAC is a three-terminal semiconductor component that conducts current in both directions when triggered. It is often used to control high-power AC currents, both as a switch and for "dimmers" for controlling lamps or electric engines.

Further reading:

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What does a TRIAC do?

I'm hoping someone on here can give me a simple explanation of what a TRIAC does. To give this request some context, I'm an embedded systems software engineer, so I interface with hardware, but I have no formal training in it. I was looking over a…
Mike
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What's the difference between 3 and 4 quadrant triacs?

I'm looking at triac datasheets, in particular this datasheet for BTA16 series triac. The "electrical characteristics" section is split into two parts: snubberless/logic level (3 quadrants) and standard (4 quadrants). I have no idea what this is…
Roman Starkov
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What does "dV/dt" mean for TRIACs?

This is probably obvious, but since I still don't have an engineering education, I ran into this problem: What does dV/dt mean? What does it affect on a TRIAC?
JacobV
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Triac Turn-on Stress Calculation

When snubbing a triac, one of the concerns is minimizing turn-on stress as your snubber triac discharges across the newly-shorted terminals of the triac. This paper says that the main concern is keeping \$ \frac{dI}{dt}\$ below the datasheet…
Isaac Sutherland
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TRIAC turning on asymetrically by itself when it gets warm

I've got a simple triac phase angle controller which is very similar to the MOC3021 data sheet app circuit. Most of the time everything is fine. The circuit looks like this: The triac is a BTA06-600B (ie standard sensitivity, not snubberless). The…
peter_mcc
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Triac inductive load

I need to drive a inductive load with a triac dimmer. Circuit uses zero-voltage cross and delay for gate trigger. An additional circuit for detecting zero current cross has been added. So, what are the correct steps in order to safely control power…
johnger
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Troubleshooting a Triac Motor Control Circuit

I have a Xytronic 988 soldering station. It has a regular soldering iron on the left and an iron with a vacuum pump on the right. It has served me well over the years and one day when I was swapping irons I accidentally attempted to plug in an iron…
user7684
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TRIAC gate resistor keeps getting burned

R85 in the following circuit keeps getting burned out when the photo-triac is turned on. It may last for a few minutes before burning out. It is a smallish 1/10 W resistor, while R83 is in DIP package. I am confused about what's causing R85 to…
Brian Wang
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What is the holding current on a triac?

What does the Holding Current characteristic mean on a triac? What does this mean for switching loads less than the Holding Current? For example the Sharp S108T02 has a max 50 mA Holding Current.
Brian Low
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Filtering out TRIAC's triggering current spike on the mains

I've got my 2KW heater controlled by a home-made dimmer, on 230V/50Hz mains. It's using the common TRIAC delayed command process. The TRIAC (BTA24-800BW) is a snubber-less kind, drived by an (non zero cross detect) opto-triac (MOC3021) parallel…
Zebu1er
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What should I take in account when using a more powerful triac?

I'm familiar with simple dimmer circuit, now I want to build a more powerful triac unit to use with a high power heater. The resistance of my heater is made of 9\$\Omega\$ 3mm diameter nichrome wire. On 240V(rms) voltage this makes 25A(rms)…
miceuz
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Triac connection for my project

TRIAC can be connected in series of 230 V. Shall I use mutivibrator for giving gate triggering this TRIAC? Also, how can I turn off this triggering by giving an external signal?
Sri Ram
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simple triac current limiter

I have a 20 liter electric storage water heater which has a 230V AC, 2KW electric heating element. The heating element is failing frequently primarily due to bad quality of water inducing faster corrosion of heating element. I decided to experiment…
jmdesai
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BTA16 triac snubber and operation quadrant

I am working on a dimming circuit to be operated by an ESP8266. I have read a lot on this over internet and got a working circuit as well. But myself I am not satisfied with my understanding of TRIACs. This question is not related to the dimmer…
Rakesh Mehta
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TRIAC won't turn on

I'm intending to control two motors, one in on/off, and another with phase control to adjust the speed. I've already implemented the zero cross detection circuit, which works fine. But even when applying 5V to the TRIAC driver, the TRIAC doesn't…
user95482301
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