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domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873
Posted: 04:26am 31 Oct 2006
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Hi,
Am dreaming (again!) to switch AC via a Picaxe. Saw a circuit with a MOC3041 TRIAC driver (zero-crossing, 15mA control current) and a TIC226M TRIAC(600V for inductive loads, 8 Amps with cooling = 1750W).
Is this cheaper to build than buying the 40A SSR from Jaycars? Not that I need 40Amps anyway. Cost is $40.
Says 25mA max. to drive this relay, is this OK for a Picaxe, which can only source/sink 15mA?? Does max. in this case mean it will also switch for 15mA?
Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up.
Winston Churchill
RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495
Posted: 04:43am 31 Oct 2006
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Forget it. Buy the SSR.
Sure, you could use a picaxe, but you wouldn't get all the benefits of zero-crossing detector, or the snubbing circuit, or probably the opto-isolation, and you would still need to provide it with power.
Not to mention the time it will take you to build it...
domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873
Posted: 03:50am 02 Nov 2006
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Ross,
Thanks for that. I mentioned that it had a zero-crossing detector, it has a snubber and an opto and all it needs is the control signal and not the power. But it could be the time to build it!
Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up.
Winston Churchill
mrpackethead Newbie Joined: 11/11/2006 Location: New ZealandPosts: 17
Posted: 10:41am 09 Jan 2007
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Suggest you use a MOC3043, almost the same as the 3041, but it only needs 5mA to turn it on. If you have an inductive load, you might want to put a 39ohm resistor and .01uF Cap in parrallel with triac.
You can use the FETS you suggested in a similar way. I've got lots and lots of mains switching being done this way of a PIC (picaxe).
Just be careful. The mains bites.
Every thing should be as simple as possible. Not simpler.