AC to DC Buck converter and Miller signs?

laz1957 posted:

Hi GUYZ,

   Wondering if I can use these AC to DC converters to power a small sign and a large sign off of one converter?  I dialed it down to 4.4 volts DC, works good on the small sign.  Do I keep it at the 4.4 VDC for both signs, will this work?  Thanks for your time.

Correct - do not change the voltage as you add additional signs and do not wire the signs in series. You are good-to-go. 

Also, as a basic barometer, assume each sign draws 0.1 amps. Depends on the size of the sign of course but this value will keep you in the green.

- The Other Guy

Thanks THE OTHER GUY!!!!

One more question, how many Miller Engineering signs can be powered with one AC to DC Buck converter?  I have two on one now can I put two more on this converter?  Thanks again.

That depends upon the rated current output of the buck converter and the current consumption of the signs. If the rated output current of the buck converter is greater than that of the total sum of the signs, you are good to go.

Like was said above. I have used small buck converters for several Miller signs, up to 3 each, no problem. I actually run them at nominal 5.0 VDC, which Miller said was just fine when I asked a few years back. 

Rod

Thank you GUYZ.  I am running 18 vac to the buck converter.  I have 3 signs powered dc at 4.5 vdc , so safely I can run 4 signs?

First, make sure the AC input (transformer) IS maxed out at the supposed 18v AC. 

Assuming the buck converter is set to output 4.5v, ,  using your multimeter,  check DC output at the converter each time you add a sign or other current using device like a building for example.  The output will continue to read 4.5 v DC, and will drop below that number if/when/as you have excess devices in the system. 

Each time you add another sign (or any other DC device), check the converter output.  As/when/if you read less than 4.5v is when the load has exceeded the AC input required to supply the devices. 

You might be surprised to see how many LED-using accessories and  devices you can support with a single 18v AC input.  I have 1/2 of my layout's lighting system on a single ZW transformer, and half on a second ZW- neither is even running at full tilt yet supplying AC for the whole layout.  

laz1957 posted:

Thank you GUYZ.  I am running 18 vac to the buck converter.  I have 3 signs powered dc at 4.5 vdc , so safely I can run 4 signs?

You are talking voltage, not current (measured in amps) and therefore applying the math incorrectly.

Mike Wyatt posted:

First, make sure the AC input (transformer) IS maxed out at the supposed 18v AC. 

Assuming the buck converter is set to output 4.5v, ,  using your multimeter,  check DC output at the converter each time you add a sign or other current using device like a building for example.  The output will continue to read 4.5 v DC, and will drop below that number if/when/as you have excess devices in the system. 

Each time you add another sign (or any other DC device), check the converter output.  As/when/if you read less than 4.5v is when the load has exceeded the AC input required to supply the devices. 

You might be surprised to see how many LED-using accessories and  devices you can support with a single 18v AC input.  I have 1/2 of my layout's lighting system on a single ZW transformer, and half on a second ZW- neither is even running at full tilt yet supplying AC for the whole layout.  

 

While this may work in a pinch, you may still find yourself finding the peak current and not the constant current and prematurely burn items out. It is much wiser and not difficult to look at the current ratings of everything to ensure you are in spec.