There are complete sets of one type for an installation or there can be a mix of types
as it seems the older types have failed or even seemingly when one or more lamps
go out. Currently as at 2018 there are rare lights seemingly from the 80's or
perhaps early 90's still around, but likely not far off being replaced.
Below are the types and brands with my observations and speculations on their history.
You can click on the pictures to view the original larger image. Locations of sparse
and rare lights have a Location link underneath to show you on Google Maps.
Braums 3 aspect signalling green, far type.
Note the diffused lens and horizontal stripes.
Braums 3 aspect signalling red, far type.
Stripe also seen on amber here.
Currently being rolled out in new installations and modernisations. As bright as their
predecessor from Aldridge, these LED based lamps have a lens to focus the light better
into the distance whilst still giving good light from any point of view to the side.
Theese lenses have a notable horizontal stripe pattern. First set I had seen rolled out
were in 2015 which was a new intersection which had been rebuilt. Since I've strangely
seen Aldridge installations in the city completely replaced for Braums without reason.
There were no defects to be seen on the original Aldridge installation, preventative
maintenance to the extreme? They indeed contain SMD (surface mount device) packaged LEDs,
the first generation I've seen rolled out in Australia with a change in LED manufacture.
Aldridge 3 aspect signalling green, near type.
Note the clear lens and visible 10mm clear LEDs.
Aldridge non-diffused green man pedestrian crossing, part of a countdown unit.
I've seen these in service since first lived the city of Adelaide back in 2000.
This has been the favoured type of signalling light for LEDs until Braums have
taken their place. Only the pedestrian crossing head uses a diffused lens,
all other shapes including arrows and tram heads use a clear lens and an
arrangement of 5mm through-hole clear LEDs arranged to create the shape.
It appears all the LEDs are in parallel as you often see LEDs which are
failing by going noticeably dimmer or flickering compared with the
remaining healthy LEDs or even dead diodes. However they are all
individual and each problem LED doesn't effect any other. Aldridge signal
lights are the dominant installed type in the state, replacing many
incandescent installations, even wiping out one type I haven't seen
since 2013. Rarely do I see the lamp / whole cluster of LEDs to one
aspect completely fail, the life of these lamps are quite amazing.