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### Topic: Hello people, I need some help about finding a specific part (Read 3094 times)previous topic - next topic

#### goldami1

##### Feb 08, 2011, 06:43 pm
I need a part that works like a relay, but doesn't have the mechanical part.
I thought about the combination of moc3041 and triac mac212, but it doesn't work because I have to control and switch between grounds, zeros.

like you see, the red lines have no 1, however, they are always on 0, that causes that this circuit doesn't work when there comes 1 logic into the moc. (The zero crossing circuit in the moc always search for that 0 to stop the power conduction of the triac (mac212)).
That's why probably this circuit will falter.
So I ask you a lot, please help me to find another solution for this purpose (and don't say me to use relays, I don't want).

Thanks a lot,
Sincerely yours, Ami.

#### goldami1

#1
##### Feb 08, 2011, 07:01 pmLast Edit: Feb 08, 2011, 07:10 pm by goldami1 Reason: 1
the rectangles are resistors, and the square is the moc3041.
and regarding the zeros - usually in this kind of circuit (with zero crossing circuit) you have a consumer with two connections to the AC power - one ground and one power.
and in this case I have a motor with one power connection and two grounds.
When I connect the power and the first ground it rounds forwards, when I connect the power and the second ground, it rounds backwards. In my case, I need to switch between the grounds while the power connection is permanently connected to AC.
For one motor I have got two such a circuits, everyone of them is connected to one Ground. the first circuit connected to GND1 and the second circuit connected to GND2.
when I send dc to moc3041, it opens the gate of the triac that is placed after the moc3041.
but the gate stays open while it gets Alternating Current, but in my solution, I control between grounds, that's why I think the gate won't stay opened (the motor won't spin).

#### goldami1

#2
##### Feb 08, 2011, 07:20 pm
can you draw it please?
I couldn't understand your explanation.

#### goldami1

#3
##### Feb 08, 2011, 07:55 pm
is there connection between the right triac and the resistor?
and can you give a simple explanation why and how this circuit will work?
Thanks a lot,
Sincerely yours, Ami.

#### goldami1

#4
##### Feb 08, 2011, 08:42 pmLast Edit: Feb 08, 2011, 08:44 pm by goldami1 Reason: 1
are you sure its gonna work?
I think there's something unclear somewhere in your circuit..

P.S
Don't forget the triac works when the AC comes to his gate and goad his state (for example, goads it to stay on conducting status) while here it's connected to grounds, from both sides.

#### goldami1

#5
##### Feb 08, 2011, 09:05 pmLast Edit: Feb 08, 2011, 09:08 pm by goldami1 Reason: 1
well, let's say I have two motors that have a common Power connection and two grounds (two motors).
Will your circuit work in such a situation?

and about the last thing..
I mean that the triac conducting current when there's dc in his first side and ac in his second side.
From what I see, we switch the motors' grounds, that means we don't deal with power, however, zeros, grounds!
So if I'm right, the triac can't work in such a way.

#### goldami1

#6
##### Feb 08, 2011, 09:58 pm
ok, if I'm talking about the simplest two motors that are connected. they both got one joined connection, while the other connections aren't.
in this situation, will it work? (this motors work on AC, they are the simplest you can find, nothing special).

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