the wicipedia page makes it sound like it is just a type of power transistor. but it is capable of handiling AC. is this corect? any other info on this divice apreciated.

 

Hello,

The following page of the EDUCYPEDIA has links about the DIAC, Thyristor and TRIAC:
http://www.educypedia.be/electronics/composetriac.htm

Bertus

 

How about the e-book available in AAC.Have a look...
http://www.allaboutcircuits.com/vol_3/chpt_7/index.html

Good Luck

 

A triac is a three legged animal that uses a small amount of current from gate to cathode to start an avalanch of current from anode to cathode that lasts as long as the current keeps flowing in the same polarity and is enough to sustain the conduction. It works in both polarities from anode to cathode and the gate voltage can be positive or negative, too.

Short answer. I hope it made sense to you.

 

so it is just a transistor that is just not as fussy and can be connected NPN or PNP style?

 

The TRIAC is like two SCRs connected together back-to-back.

Thyristors behave differently from transistors, as once they are turned on, they stay turned on until the current flow through them falls to zero. This is why they're used with AC. SCR's can be used to control brushed DC motors, as the current flow is interrupted by the brushes on the commutator.

 

A triac is not like a transistor. Once it is started it is uncontrollable. It only stops when the supply current stops or changes polarity.

 

Under the right conditions, transistors can have a more or less linear progressive response, where increasing input produces increasing output. This means that they can be used to make amplifiers and related analogue circuits.

The SCR is a switch that can only be ON or OFF - no in-between. As mentioned by others, once on they stay on with no further gate input needed, until the output current stops e.g. due to the interruptions which occur with an AC supply.

 

so i could use a SCR as a charge controler for a battery or cap? when the voltages = it would shut off?

 

Google found this;


What is a traic?
In: Language & Lookup › Definitions

Traic = Traffic. N 1. Vehicles on a road, especially when there are many. 2. The number of people who visit a web site. 3. v. To deal in, trade or sell.

 

Geez, you can even purchase a TRAIC from digi-key!

http://parts.digikey.com/1/parts/1807547-ic-traic-25a-800v-iso-to220-3-bta25h-800cw3g.html

 

Re #9

All Triacs have a minimum hold current. If the battery charger current drops below the hold limit, the Triac will shut off and wait for a new gate signal.

 

i'm not lookoing for traics i just have ran across them from PCB i have destroyed.

 

Google found this;


What is a traic?
In: Language & Lookup › Definitions

Traic = Traffic. N 1. Vehicles on a road, especially when there are many. 2. The number of people who visit a web site. 3. v. To deal in, trade or sell.

Do the term lysdexia mean anything to ya?

 

Ahh we all can get letters mixed up in words especially words we don't use much or know well.

Surprisingly, a little bit of effort does wonders in achieving better spelling!

And I apologise to the OP for posting facetious humour.

 

Ahh we all can get letters mixed up in words especially words we don't use much or know well.

Surprisingly, a little bit of effort does wonders in achieving better spelling!

And I apologise to the OP for posting facetious humour.

Many dyslexics do have difficulty recognizing swapped letters in a word. Paying closer attention may not help (not sure).
This problem is totally unrelated to intelligence.

 

Agreed! And I was not implying in any way that dyslexics are dumb.

But I still insist that a bit of care goes a long way in spelling words right, for all people.

(and was originally referring to the OP's; ) traic, wicipedia, corect, divice, apreciated.