A TRIAC is an component often used to control high power currents, both as a switch and as a "dimmer"-like construction for controlling lamps or electric engines.

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How to trigger triac using DC?

This video features a circuit that triggers a triac using a DC: https://www.youtube.com/watch?v=ZXXup79B6Gc I would like to make a little modification on it it. The video says that I have to connect ...
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93 views

A question about very simple light Dimmer circuit?

I've learned that a Triac works as a switch for controlling AC current. Why not connecting the load (L1) and Triac in series? at the position of red arrow? My reason is that a small amount of current ...
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95 views

Triac dimmer component

I was looking for a way to dim a regular light bulb in a circuit. With the help of this site, I learned that using (variable) resistors would dim the light, but eat up electricity in the form of heat. ...
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2answers
90 views

What type of Resistors be used with Triac terminals? 1/4 or 1 watt

I have used BTA41-600 with MOC3083. I Keep frying my MT1/2 connected 330E and 360E resistors. Resistors were used as per datasheet recommendation. I was using 330E and 360E but, both kept frying. 240V ...
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511 views

I am using a triac bta41-600b with MOC3083, doesn't work

I have used the circuit from Datasheet of MOC3083 directly. Problem is triac does not fire. 0.1uF cap is MPF and all the values given in data sheet are used as they are. I am using a 100W incandescent ...
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1answer
81 views

Electromechanical or Semiconductor solutions to control chandeliers and homes stuff

I've been designing some wireless modules and finally got them to work and now I have a network of them and want to use them for home automation purposes. Controlling stuff like chandeliers, heating, ...
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61 views

What happens when triac terminals MT1/MT2 are switched?

According all literature, terminals MT1/A1 and MT2/A2 must be connected to neutral and phase respectively. What happens if you reverse the wiring? House sockets here are randomly wired, so it's a ...
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1answer
161 views

Digital replacement for Rotary Capasitor based fan speed controller

Is there a circuit using Triac and capacitor in series to control the speed of ceiling fan? There is a circuit using SSR but I wish to use Triac as SSR are bit costly. http://www.edcheung.com/automa/...
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259 views

Triac fails unusually

The circuit is a MCU triggered, capacitor based fan speed controller. The circuit works fine when a single triac is connected but when both triacs are wired and triggered alternately, any of the ...
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2answers
147 views

Braking a motor commanded by an IC H-bridge

Firstly, some premises of the design are related to the high speed needed (maximum as possible) and precise stop point. The motor is feed at a maximum of 40V and consumes at normal operation 1.5A. Due ...
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1answer
173 views

Better triac gate configuration

I'm an intern who was tasked with finding a way to switch on a motor and solenoid from either 120 or 240 VAC. The circuit on which my supervisor suggested I base my design can be seen below. My ...
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3answers
363 views

Optoisolator with EL wire won't turn off, TRIAC works fine. Why?

I'm pretty new to electronics, and I'm making a circuit to control EL wire with a DC logic control signal. Specifically, I would like to blink the EL wire with the output of a 555 timer. My first ...
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1answer
498 views

Parallel TRIACs driving same load

I am designing a series of heaters. One of them, actually, is designed for 220V and uses two resistors on series to achieve the power desired. The total current is, on peak, almost 20A. To keep the ...
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1answer
100 views

Can someone verify my EL wire oscillator?

I'm pretty new to electronics, but my latest project is a circuit with two "frames" of animation that I make out of EL wire, and I want to build a circuit to switch between them every 2-3 seconds or ...
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1answer
55 views

Gate controlled turn-on time

Under DYNAMIC CHARACTERISTICS for BT137 is Tgt value set to typically 2us. If I then look under BTA16, I see no mention of the pulse width. Is there a minimum pulse width as a standard value for all ...
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1answer
154 views

Sensitive or not sensitive gate? [closed]

If there is nothing about it in the datasheet, how can I find out if it is a sensitive or not sensitive gate?
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1answer
98 views

Difficulty understanding data over opto-diac

I'm having difficulty understanding the data over MOC3021, DIAC side. Should I see it as with DB3? So DB3's \$V_{bo}\$ (28-36V) is the same in opto-diac, and DB3's \$V_o\$ (min 5V) is the same as ...
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1answer
88 views

How is it possible to use TRIAC dimming with an 110v input LED T-8 Tube light?

I have seen T8 or T10 Led Tubes made for entertainment lighting that can plug into a Triac dimmer and be dimmed down to approx 10% with no flicker and no color shift. Attached is a picture of the ...
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1answer
105 views

Switch high frequency AC on/off at zero crossing

I have a 3 phase generator which is powering some system. (50Vrms @3A, with variable frequency from 50-5KHz). I've used mechanical relays to control each phase to the load. However, there was no real ...
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2answers
93 views

TRIAC controlled fan voltage issue

I have a question that seems to baffle electricians that I've spoken to. I'm running a 115V Fan off a TRIAC controller that utilizes a 0-10VDC control signal. When I power the DC control signal down,...
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1answer
387 views

Question regarding a resistor in optocoupler/TRIAC circuit

I'm building a ac motor starter with a optocoupler (FOD4218) and a TRIAC (BTA16), one for each phase in a three phase 400V system. I have a question regarding the circuits that can be found all over ...
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2answers
238 views

Parallel TRIAC's for greater heat dissipation

Is it possible to parallel TRIACS to lower heat dissipation per device? If so, what would be the best strategy to ensure balanced current sharing between devices? The target application is to switch ...
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2answers
245 views

Triac - opto-coupler Circuit Confusion

I have the following question regarding this circuit: How is the opto being used to trigger the base of the triac?The collector of the photo-transistor is connected to the base of the triac. As per my ...
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1answer
86 views

Considerations when repairing dimmer switch

I originally asked this question on DIY StackExchange. So far no answers and a suggestion to try on Electronnics, so here goes: I have an IKEA lamp with dimmer switch which took a knock and ...
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4answers
65 views

230V AC Wave forms in an analog ocillocope

I was doing a project on AC Phase control using triac,and I needed to see the phase controlled waveforms in a scope.But the scope that I am using has maximum volts/div as 5V (found on many scopes as ...
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3answers
204 views

Live switching AC loads with TRIACs or SSR

I have been designing a system whose purpose is to provide high reliability to a set of outlets (8), it takes to inputs of diffrent phases mains current, now the purpose of the system is that if the ...
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1answer
423 views

triacs from dishwasher

I have PCB from broken dishwasher and I would like to learn something from it. There are 6 smaller - STMicroelectronics Z7S, 1A triacs and one bigger STM T4 3570. My guess is (cannot verify it now) ...
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1answer
339 views

Power supply for an irrigation system

My irrigation system control box just died and I'd like to replace it with a smart controller based on a Spark Core programmable board, so I can monitor temperature, soil moisture, humidity, and other ...
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2answers
8k views

how does the circuit of a basic Variable speed electric drill work?

i am trying to 'automate' the control of an electric drill motor that im taking from a garden variety Variable Speed drill (from Harbor Freight) it has a universal AC motor which I basically ...
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1answer
102 views

Traic switching in 3+ quadrant

I am controlling fan speed using Triac phase control with a circuit similar to this. The problem that i am facing is that my triac burned out after using it for 2 3 days and after burning it will ...
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1answer
1k views

Why do we prefer zero-crossing optotriacs for driving triacs?

I usually see a special type of optotriac which has internal zero-crossing detection circuit in it. This type of optotriac is generally used for driving triacs. But, I don't understand its necessity. ...
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1answer
474 views

How to correctly simulate Zero Cross Detector Circuit?

I am trying to simulate a circuit for Zero Cross Detection. The end goal is triac phase control. My simulation using proteus hangs up and with message "Simulation is not running in real time" and ...
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1answer
196 views

Wired Or of Triacs don't seem to work

I am trying to make a full sine wave from two half waves wire-ORng through triacs However, as long as the triac output terminals (MT1 for both) are not shorted, the signals seem fine. When I short ...
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1answer
144 views

High Voltage Triac Control

I'm trying to control a universal motor run from a 240V power supply using a micro-controller. There is a existing PCB that uses a potentiometer to vary the speed that I am trying to replace. I've ...
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2answers
227 views

Triac circuit confusion

X1Iz.png I have the following questions about the above circuit: -Why are we even using a trica/diac combo above. Why would a circuit consisting of just the fuse, switch and primary not be ...
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1answer
100 views

Switching 150kHz mains for an LC load

I'd like some input on whether or not to use a mechanical relay or some form of SCR setup to change the capacitance in my LC circuit that is currently operating at around 170V, 1A at 150kHz. (Not 220V,...
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2answers
388 views

Arduino Dimmer Shield Schematics Interpretation

I've read so much about Thyristors, Triacs and Rectifiers on the last days that I'm almost understanding my schematic, but I'm not there yet - I need some help. Overview: I'm making a home automation ...
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1answer
828 views

Why do we use a diac for triggering a triac?

I mean, Wouldn't it be possible to give a gate pulse on triac directly? I have seen in many phase control application circuits like fan speed control,the usage of diacs to trigger a triac.
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1answer
910 views

Short circuit protect for Triac

I'm going to use this circuit to control some lamps. As I know a short circuit would cause the Triac to burn very fast and I need a way to protect it. Using fast fuse is cool but I need to know If any ...
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2answers
403 views

Turn a mains light on slowly

I've been looking at creating a simple circuit to slowly turn a halogen daylight bulb on over about 30 minutes as soon as power is supplied to simulate dawn. I've got a 240VAC 42W halogen bulb that ...
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1answer
645 views

Will replacing the MOC3024 with MOC3021 make any change

I'm student of 10th grade and new to electronics I'm trying to make a switch to control appliances which runs on AC mains and I don't want to use any relay see the circuit diagram from the link to ...
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1answer
529 views

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 ...
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2answers
3k views

Do I need zero-crossing detection for controlling a heater?

I need to control a heater element (about 500W) using arduino. For switching part I would go with zero-crossing SSR or zero-crossing optoisolator and triac (the second seems to be cheaper). The ...
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1answer
238 views

Driver for triac

Can you explain this schematic: Especially part where are optotriac and triac. I can't understand why if turn on optotriac \ then main triac will be open. Because I made a real scheme and ...
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1answer
2k views

Water pump with opto-isolator MOC3063M and triac BT137

I have designed a circuit for water pump. Please correct me if I am wrong with schematics. The idea is to to switch on/off AC motor pump with 230V and 7.5A, when water is detected. I have used opto-...
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3answers
451 views

Triac power switching

Given the circuit below: (I simply plan to switch the light bulb on/off and I will later add an optotriac to the gate.) As I understand, the circuit should work in this configuration, and the ...
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2answers
649 views

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-...
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7answers
4k views

How to throttle power consumption of a heating coil?

Which is an appropriate but simple electrical circuit to reduce the energy (power) consumed by a heating coil which has an AC feeding without generating an asymmetric load (large DC component, e.g. ...
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2answers
313 views

How to replace the rectangle(DIP) bridge rectifier with round one.

I want to make an AC dimmer and the circuit diagram from the instructables uses a bridge rectifier which is in DIP package and rectangle in shape and the rectifier which I have is round one, so how ...
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1answer
111 views

triac DC ground and AC live

In this example of using a 3Q triac, could the AC voltage flow into the DC terminal?