In the same vein as this topic: https://forum.allaboutcircuits.com/threads/bunkerhill-security-light-modification.81163/

The newer 115 lumen version of this light does not use the same PCB as the previous versions. I am hoping someone can help me work through a way to disable the 'always on light' functionality, and instead only activate the light when motion is detected. In the previous topic, there was a specific resistor identified that when removed, offered this functionality.

I have attached a picture of the PCB. It's been a long time since college electronics class.

 

Welcome to AAC.
Your comment doesn't make sense. Always on and "when motion is detected" seem to contradict each other. If the lamp is always on then there would be no need for a motion detector. No? If the light is on at dusk and off at dawn then it has a light sensor. That sensor might need to be disconnected or perhaps shorted. And without knowing more about the circuit I wouldn't recommend experimenting with shorting it. Do you have a picture of the other side of the board?

 

Always on and "when motion is detected" seem to contradict each other.

This is fair, I did not state this accurately.

Once the solar panel production drops to a certain threshold, the circuitry assumes it is night time. At that point, a dim light is always on (something like 25% luminosity). When motion is detected, it kicks into a higher brightness mode for 30 seconds.

What I am trying to disable is the always-on-dim mode. Ideally, the light would function by *only* turning on the light when motion is detected. Previous topics on this forum have addressed older versions of this light and discovered a workaround to facilitate this style of operation.

 

THAT is quite a different change in the requirement. It is also what I would want to add, since always on dim is a waste of power. If we had the actual circuit we could see how the power is controlled, and possibly remove the "DIM" power feed, if it is different. Otherwise, adding a series diode to the switch transistor base circuit will possibly prevent the switching on until more drive id provided. OR putting the diode in series with the LED power feed.
OTHERS may have a better idea .

 

For the older units, the fix makes sense. There probably was a higher value resistor in parallel with a switched lower value resistor. In this new unit there is an 8-pin chip. This might be a microcontroller that controls lamp brightness with pulse-width modulation. If so, then all of the lighting modes might be created in software. If so, then nope.

ak

 

To come up with a reasonably good answer I need to know the control scheme, at least to some extent. It gets complicated if the DIM/BRIGHT control is a single device , either including themotion sensor or not.