TRAIC BTA08 connection to Mains

Hi All,

A little confused with the BTA08 TRAIC. Attached is my schamatic. I’ve mpt connected the load but have mentioned it.

So the whole idea is to switch on the load by firing a pulse at the gate of the TRIAC. Is that how the wiring for the mains should go ?

Any suggestion is appreciated.

Solved !

Solved !

The whole point of making posts visable and available to everyone in the world is so others can benefit from an OP's post. Posting and then saying it is "solved!" without explaining HOW it was solved helps no one and makes it look like all you care about is your problem and don't really care if anyone else learns from your post. You've only been on the forum for a couple of months but you have 134 posts so you aren't exactly "new" (1 post, 0 karma) to the forum. One would assume that you know this is an "open source" forum and that other's read your post (or you wouldn't be posting). The question remains then, why have you not posted an explanation for how your post was "solved" ? Were you not aware of the custom of explaining how it was solved ? Also, if you are really going to post "solved", it does no good to post it in a reply. You have to edit your original post title and change it to :

[SOLVED] TRAIC BTA08 connection to Mains

First of, Let me apologize for the post that only mentioned "Solved".

The reason to post it so was because i did not get a reply to the post. Since it was a small error, nobody had replied to it so i thought no would even bother to know what the problem was and how it was solved. So to keep it short and avoid any further replies (since I've already solved it) i left it as "Solved". yes i understand it is an open forum and all expect a little help from each other, so did i.

The error in the schematic was that the neutral side of the load had to be connected directly the neutral side of the AC and not in junction with the snubber circuit.

The error in the schematic was that the neutral side of the load had to be connected directly the neutral side of the AC and not in junction with the snubber circuit.

There error is in the fact that whoever made the schematic did not designate Line (hot) or Neutral.

That being said, what, pray tell , is a "Neutral side of load" ?

What kind of ac load is "polarized" such that it matters which side is neutral ?

(certainly not a motor or a lamp or any number of other ac loads)

A computer would be an exception to the extent that the computer power cord is probably "keyed" so as to go in only one way.

What (exactly) IS the load ?

A little confused with the BTA08 TRAIC. Attached is my schamatic. I've mpt connected the load but have mentioned it.

Nothing in your post suggest that you actually tried powering it before marking the post "solved". You never did say what the load was or that you had tested it. What makes you think it matters how you connect it ? (L, N) or (N, L)

Also, as I mentioned , in order to mark a post "solved" you need to edit the post title of the ORIGINAL POST , (not a "reply") and change it to "[SOLVED] etc. etc. etc. " which you still have not done.

FYI, in case you aren't aware, the fact that the person who drew the schematic does not have the GNDs pointing DOWN is an indication of inexperience, at least with schematic conventions, since all schematic drawn by professionals show GND pointing DOWN and any Vcc pointing UP. (GND should NOT be pointing UP or LEFT or RIGHT). It should be pointing down. It is the responsibility of the person making the schematic to use connecting line to accomplish that so there is no excuse (other than pure inexperience) for doing that. Also, the 7805 regulator circuit is upside down. There's no current limiting resistor in series with the power on indicator led on the output of the regulator.

You might encounter issues depending on how you intend to drive the optical DIAC (the MOC3023). If it'sdriven from a PWM signal, there can be interactions between the PWM frequency and the 50 or 60Hz line frequency (probably not an issue with the high PWM frequency used in Arduino micro-controllers). The other problem is that if a PWM output from the micro-controller is used to feed the MOC3023, it will tend to fire it at a constant frequency since the PWM frequency isn't changing - just the duty cycle. That can result in unexpected behavior of the load control circuit (lack of control). Frequency of the pulses to the DIAC is usually used to control the load.

Just something to be aware of - then again, you probably aren't driving the DIAC from a PWM signal.

Thanks guys, and yes am not very experienced in the design part of circuits. In fact this would be my first.

So the load would be a transformer, an MOT to be exact. The live neutral do not matter here, just named for the sake of electrical terms.

So the circuit does not seem to be working, not powering on in the first place. checked the voltage at the secondary and it shows 2.5 Vac, thought the transformer was not working took it out of the breadboard and connected and it shows 13VAC. The voltage regulator does not have a 5v out either.

Where would the problem be? where have i made the mistake. Schematic attached.

Schematic attached.

Are you sure ?

As far as troubleshooting, you have not posted any code or test point voltages.

You should break the circuit down into stages and troubleshoot each stage separately.

You have a stepdown transformer but no information about the transformer.

Ooops Missed that out. bmp file was rejected but was posted without it. Here it is. The mains out here is 240 and the transofmer primary is rated at 230 and secondary is 9v. Arduino Code is working when tested and on the arduino. its just that the transformer is behaving a bit weird.

hmmmm so there was a short between pin 3 on the regulator and the gnd. isolate that and have to power the MC next.