MZ770s photocell problem/testing

[Bilko]

How can you test the above photocell?
It doesn't seem to be an Infra red or UV flicker sensor just a plain photocell
Using it connected to a Satronic TF830 oil burner controller which is just cycling on/off- so I suspect the photocell

What meter reading might one expect to read on test?

cheers
Bilko

 

[wilhelm]

aint got a clue. I just slave in a spare. fekkin meter??? lifes too short to prat around.

There are other issues , when u say cycling on/off...


have u been fiddling etc??

 

[Agile]

I dont know the exact characteristics of that particular photocell.

Most of the older photocells on oil boilers are cadmium sulphide cells in an evacuated glass envelope.

The have an operating voltage of about 10-100v and a dark resistance of over 1 Meg and a daylight resistance of about 100k which falls even lower when looking at a hot flame as they have a peak response to near infra red.

So you could apply say 9v to test and get about 180 µA in strong light falling to virtually zero in the dark.


Tony

 

[Bilko]

cheers chaps.

It does look like the cadmium sulphide type.
It does seem to be responding but with higher readings.
Ordered another now to substitute.


Messing with it??? not me