I have a Heath Zenith Dualbrite motion sensing light. The light is designed to shut down during daylight. I had reason to investigate the workings and was stunned when I looked inside expecting to see an obvious photocell. The first photo shows what a clear window which allows light in sees. Is this an integrated circuit which includes the photocell? The second photo is the other side of the green vertical card. The next photo is a top shot of the complete circuit board. And the bottom of the circuit board. And here is possibly something similar to the circuit schematic. Can anyone help me identify where the photocell is?

 

There is a conductor connected to the CDS component identifier on the board, CDS which is usually a Cadmium Sulphide detector.
The conductor should lead to the Detector.

 

Thanks for your reply. There are two detection systems on this unit. One detects motion and the other detects day light. Which detector are you referring to? The motion detector is in an enclosure on the top of the light as shown on the attached. I am hoping to find the detector for day light. The window for day light is in the mounting base of the light.

 

In the first photo trace the white wire in the gray cable that's connected to the CDS marking on the pcb to find the daylight sensor.

 

This would imply that the photo cell is under the black coating circle shown on the vertical card in the second photo. Can it sense light under that coating?

 

There is a conductor connected to the CDS component identifier on the board

Barely connected…

 

This would imply that the photo cell is under the black coating circle shown on the vertical card in the second photo. Can it sense light under that coating?

No, the white wire that goes to the PCB into a one of two holes marked “CDS” should have a light sensor on the other end.

It is not on the board, though it was designed that way originally.

 

 

hi cst,
What is connected at the other end of this thick grey cable.?
E

Added:
Checking the web suggests a wide range of body/housing styles for the lamp system.
It is possible that a common PCB layout is used in many of the models, so the CDS sensor maybe located elsewhere on the body and the single White wire a feed in from the remote location.?

 

Okay, I finally get it. The thick gray cable goes to the top of the lamp where the motion detector is. So both detectors are on the top of the light fixture. The clear bulb on the mounting base must have been used in an earlier design where they placed a photo cell at the CDS connection. Thanks to all for your persistence. I kept looking for a photo cell exposed to the clear window shown in attached photo between two switches.

 

To close the story, here is a photo of what is in the top of the light. Thanks again for all the help.

 

And as can be seen, the white conductor goes to the CDS detector just to the right of it.