http://www.chrisncarol.com/switch.jpg
would this be ok, basically when the 555 is high load1 is active when
it's low load2 is active, is this correct?
Thanks
it's an unusual looking circuit (there's a short circuit through the two
first output transistors) what's the intended purpose of C3
you can simpply connect the optocouplers (and resistors) above and below
the output of an NE555 to have them firing alternately.
you have the 555 configured to be on for upto about 4 seconds (adjustable)
and then off for about 15 miliseconds (or approx one mains cycle) - is
that what you want?
if you want an even mark-space (on and off for the same length of time)
connect the 250K pot between pins 3 and 2 and disconnect pin 7 and remove
R10
something like this
0V +--------------+--+5V
| | . . . . . | . . . . .
+------(---.1 . . 8.--+-[220R]---.1 6.
| 22u | . ~ . .MOC3022.
+--||--(-+-.2 7. +--------.2 5.
| | . NE555 . | . .
+------(-(-.3 6.--+ | .3 4.
| | | . . | | . . . . .
+---+ +-(-.4 5. | |
| | | . . . . . | | . . . . .
| v | | +--------.1 6.
+-[250K]-+------------+ | .MOC3022.
| | +--.2 5.
+-----------------------+ | . .
| .3 4.
0V--[220R]--+ . . . . .
The stuff on the other side of the optocoupler seems needlessly complex
but I guess that depends on what the load is you intend to drive. doing
that part the way you plan won't cause any problems.
It appears that you copied the a "solid state relay" schematic from
somewhere (and got atleast one copy wrong)
You don't need the whole solid state relay input stage if the input
has a predictable voltage range. a simple resistor is sufficient...
the 3022 has a 10mV input
sensitivity and Fairchild suggests feediing it about 15mA in case it
degrades a little, the internal LED has a voltage drop of about 1.5V
so 15ma at 3.5V comes to 233 ohms so 220 is close enough.
Bye.
Jasen