We have a 12
circuit Okero 1295
dimmer acting up. One
circuit is always on no matter what
DMX signal is sent. Another
circuit randomly
fade up and down even if the
dmx value is fixed.
I guess the always one could be the
thyristor(assuming it is dimmed by one) being broken. The other one I have no idé about whats wrong.
I have found the Datasheet but no
manual or instruction on switching individual dimmers.
http://www.okero.se/PDF/OKERO/Man-1295-eng.pdf
I know this is not one of the standard dimmers on CB, but have anyone worked with one of these?
I haven't worked with this
dimmer, but the data sheet states that it uses 40A 700v Triacs. Depending on the case configuration of the
Triac, this should not be too hard to find. I have several that I have purchased from mouser.com in the US, that have the TO3 case style, except with .250 spade lugs on the top of the case. I am sure that there are some electronic component supply stores in Stockholm or Goteborg, maybe even Malmo. (Sorry, I don't know how to make the correct Swedish characters on my computer.)
As for the
dimmer channel that is doing it's own thing, look for an 8 pin DIP chip with the labelling MOC30XX. (the XX represents two other numbers that might be on the chip, following the MOC30, such as 12 or 22). This is the chip or integrated
circuit that triggers the
Triac, and might be sending erronious signals. There are also a few risistors and possibly a
capacitor that should be near that chip that might be a problem. They are usually a 0.01 or 0.1 uf
capacitor and a 180
ohm and a second 180 or 100
ohm resistor on one side of that chip and a 330
ohm resistor on the other side of the chip. These could all be a contributing factor in Triacs being triggered on and off in an random manner.
I lived in Sweden way back in 1961
thru 1963, but I am afraid that my Swedish has all but vanished. Good luck
Tom Johnson
Florida's Most Honored Community Theatre
