Re: CO2 controller

Thomas Sebastian Szymkiewicz wrote:
1) I connected one of the leads from a 12.6V AC transformer to the
left-most lead of the 5V fixed regulator.  2) I connected all ground leads
to the other lead of the 12.6V transformer...is this my mistake? Shouldn't
I connect it to something that has a potential of 0 with respect to the 5V
in the circuit and not something that varies?  This seems to be a pretty
dumb mistake to me, but again, I have no experience or training in
electronics...only physics. 3) Nothing happened...isn't the green LED
supposed to light all the time? I tried covering the photocell and
uncovering it, and nothing happened.

Is the current entering into the circuit supposed to be DC in which case I
would have to build a four-diode device described in one of my books to
convert the AC to reasonable DC?

Yes you need a a recitified and filtered DC input for the regulator. In
addition to the diode bridge, you will need a filter capacitor, something
in the range of several hundred microfarads. An alternative to the 12.6
voly AC transformer with diode bridge and capacitor would be to use a DC
output wall mounted pover adapter.

Am I correct in connecting leads 3 and 4 to the ends of the diode?  Are
leads 1 and 2 connected to the solenoid?

I can't tell you how to connect your relay, as the numbering is arbitrary.
I assume the diode is connected across the coil (i'm not familar with the
circuit you're trying to build). You can probably find the coil terminals
by using an ohmmeter. Sould be in the 100 ohm or so range when your accross
the coil.

Even more questions:  Can I replace the 500 microF capacitor with a 470