whats a lamp regulator?
do you mean a triac dimmer?
if you have problems firing at low angles try using a voltage with a
different phase angle for the firing pulse (if you use simple diac triggerdiode).
but i would suggest using a small analog circuit, generate a triangle/ramp
voltage syncronous to the mains power and compare to a constant "should be
value".
this gives very accurate setting of phase angle.
also you can add burst fire simply, which may be useful with inductive loads
and output voltage.
maybe this helps you..
but also the following may occur:
i don't know the chemical process you use but it may possible the
electrochemical voltage is at 0.6V, this then may cause that the current stops
immediately under 0,6.
if it is the regulator i can only suggest to get the scope and look at the
signals, these ready-made lamp regulators are only good for setting a lapms
intensity.
if you really want a good constant current then maybe make a feedback
regulator.
i discovered it more simple to keep the whole control/firing circuit at
secondary potential.
then you can use optocouplers only with on/off signal (firing bursts / mains
sync).
this is much better in long-term stability than coupling any analog signal
back, optos degrade with time, you would need to compensate that.
on the other hand - if your process/plant doesn't change over the time (the
resistance of the bath stays the same) then no regulation is needed and you
simply can set the value with a variable resistor (like it is now i guess)
regards
stefan
> Hi Adam,
>
> After some testing, it turned out that you were absolutely right. Not
> that I really would have doubht it - It came even worse in that the
> anode bags - which were wicked around the iron on top of the anodes
> soaked up the solution. As a result the iron started to corrode....
>
> I meanwhile have followed your sugestions. That is I made it slightly
> different in that I drilled four threads into the anodes from top, and
> screwd four solid copper wires into them. On top I also replaced the
> iron with plastic bars. The wires are now PVC insulated and I used
> glue to isolate the coper wire / anode interface.
>
> You can see pictures of the changes here
>
> http://www.myhome.ch/mzingg/pcbstuff/tps/
>
> click on "updates to the station"
>
> While I think it's now done the way you meant, I still really
> apreciate your feedback!
>
> There is another probelm left open with the powersupply. It turns out
> that the lamp regulator I use does not start up immediately and as a
> result the transformer first outputs about 3V. There are ~40 Amps when
> plating starts, and trying to regulate it down leads to the effect
> that I can only go down to 10 Amps at about 0.6 V. Below current stops
> flowing immediately. I'm now considering adding diodes in row to the
> cathode line to have the transformer operate at a higher voltage...
>
> I first hoped that the fact that now that the anodes are floated
> completely this would change but it did not.
>
> How did you do your power supply?
>
> Markus
>
>
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>
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