Low voltage lanscape lighting

[hobbes]

Hi,

I am thinking about installing low voltage landscape lighting (12v). I learned of voltage drop in that light bulbs further away from the transformer will be dimmer than ones closer to the transformer.

The solution is to try and set up your lighting runs such that clusters of fixtures are sufficiently close together so that the voltage differentials are small.

My question is would it be possible to also vary the wattages of the light bulbs on the same run to even out the light output. For example I would place a 20w bulb close to the transformer. And then further down the run I would put say a 50w bulb. The 50w bulb would have lower voltage, due to the power transmission losses, but would draw more current and hence get to the same light output.

Has anyone tried this? Or is it that in practice it is very difficult to get the light outputs to match well.

Best, Mike.

[Mikepier]

That would be the case if the lights were wired in series. But if they are wired in parallel, each light bulb would get the equivelant voltage the power supply is capable of. The power rating of the power supply you get depends on how many bulbs you intend on using.

[jmagerl]

[bud--]

In a slight variation, you could feed one of the wires at the 'near' end (the other wire not connected at the 'near' end). Feed the other wire at the 'far' end. All bulbs will be the same brightness.

If the bulbs are run in series, the current through each bulb is the same. If the same type bulbs are used, each will be the same brightness.

Wired in parallel, the voltage at the far end is lower because of voltage drop along the wire as the OP said.

-- bud--

[Mikepier]

True

Not true. While the current is the same, the voltage across each bulb will not be the same because of the voltage drop across each bulb.

I think you have your series and parallel circuits mixed up. You will definately have a lower voltage at the far end if you wired the bulbs in series, but if you wire them in parallel, and assuming you use a heavy guage wire and a high KVA power supply, you should get little or no voltage drop at the far end.

[Big Al]

Think out what you're saying. In series the bulbs will be the same brightness. This statement is dead wrong: "You will definately have a lower voltage at the far end if you wired the bulbs in series"

Al

[bud--]

"Same type bulbs" means same resistance for each bulb. Same current through same resistance means same voltage drop across each bulb. Same current and same voltage at each bulb means same wattage at each bulb and same brightness.

If the near end bulb gets the same voltage, increasing the power supply KVA has no effect on voltage drop between ends.

If you use a superconductor there will be no voltage drop at the far end. The OP asked a question about the wire he was likely to use.

-- bud--