I'm tasked with repairing a Malibu Landscape Lighting set that is exhibiting parasitic draw.
It's a 12VAC setup, old (20+ years?) unregulated linear transformer design with optical sensor, multi-position switch for hours runtime, and a relay to switch power on and off. Originally had ~10W incandescent bulbs.
After swapping (AC tolerant) 1.5W LED bulbs in, it is now lighting the LEDs very dimly after the intended power on period has ended, and they stay on dimly until next power on cycle. They do get up to full brightness when they are supposed to be powered. It occurs to me that this parasitic draw may have been present previously, but had gone unnoticed because not enough current to make the original incandescent bulbs glow.
Does anyone know of a schematic for this or similar non-SMPS based outdoor lighting?
Any ideas on what could be causing the parasitic draw? I have not had a chance to tear it apart yet, but wondering if it might be something like carbon fouling in the relay. Given it is outdoors I suppose it could even be bug parts or spider webs causing a resistive path, but doubt it is water as it has had plenty of chances to dry out after rain and isn't very exposed to it.
I suppose after being outdoors for so long it could even be traces coming off the PCB to cause a short but I'd think that soon enough, that would have stopped normal power-on operation while it has done this for months now.
It's a 12VAC setup, old (20+ years?) unregulated linear transformer design with optical sensor, multi-position switch for hours runtime, and a relay to switch power on and off. Originally had ~10W incandescent bulbs.
After swapping (AC tolerant) 1.5W LED bulbs in, it is now lighting the LEDs very dimly after the intended power on period has ended, and they stay on dimly until next power on cycle. They do get up to full brightness when they are supposed to be powered. It occurs to me that this parasitic draw may have been present previously, but had gone unnoticed because not enough current to make the original incandescent bulbs glow.
Does anyone know of a schematic for this or similar non-SMPS based outdoor lighting?
Any ideas on what could be causing the parasitic draw? I have not had a chance to tear it apart yet, but wondering if it might be something like carbon fouling in the relay. Given it is outdoors I suppose it could even be bug parts or spider webs causing a resistive path, but doubt it is water as it has had plenty of chances to dry out after rain and isn't very exposed to it.
I suppose after being outdoors for so long it could even be traces coming off the PCB to cause a short but I'd think that soon enough, that would have stopped normal power-on operation while it has done this for months now.