Gilderfluke&Co DMX-512 Input DC Dimmer - Manual (Page 8)

Lg-DMX/DC Connections
There are only a small number of connections on each Lg-DMX/DC:
1) Power:
The Lg-DMX/DC will run on any DC voltage from about 9 volts up to 24 volts. This power can come
from batteries or a DC power supply that is run from line current. The incandescent lamps, LEDs, motors,
or whatever you are controlling also run from the same power supply. The voltage that these devices need
to run will determine the voltage of the power supply you will be using.
The DC fed into the Lg-DMX/DC does not have to be filtered. If you are running incandescent lamps, a
bridge rectifier can be used between a simple transformer and the Lg-DMX/DC to full wave rectify the AC.
If you use an unregulated power supply, you may see some variations in your controlled devices as the
voltage sent into the Lg-DMX/DC wobbles. If your loads are going to be constantly changing levels (as on a
light parade float or flicker flame effect), you will never see these variations. A regulated power supply will
always give you more consistent lighting levels.
The power supply will have to be sized appropriately for the loads you are controlling. If you are simul-
taneously controlling ten amps on four outputs, you will need to use a minimum forty amp power supply!
Most larger supplies these days are ‘switching’ types. Large linear power supplies are available, but less
common. ‘Brute Force’ power supplies are basically a transformer, rectifier and capacitor. These are big
and (relatively) cheap, but are unregulated. If you are on a budget, there are a lit of cheap ‘battery elimina-
tor’ power supplies that are made to run auto accessories from a wall outlet. These put out 13.8 volts DC,
and are available in either regulated or unregulated models.
Because incandescent lamps draw the greatest current when they are just turning on, you may need to
allow additional current capacity for this. If you find that this causes a power supply voltage drop during an
installation, you can ‘warm’ up the lamp filaments by setting them to 5 or 10% (bright enough to start glow-
ing) for a second or two before turning them to a brighter level.
Because the power supply may be providing a great deal of current, you will need to wire the power
supply to the Lg-DMX/DC using heavy gauge wires. The longer the wire runs are, then the heavier the
wires will need to be. If your wires get warm, or you measure a large voltage drop between the power sup-
ply and the Lg-DMX/DC, then you need to use heavier wires.
The continuous current load on the Lg-DMX/DC should not exceed forty amps. This is the current rat-
ing for the power screw terminals.
If the voltage being fed to the Lg-DMX/DC ever drops below about five volts, it may cause the Lg-DMX/
DC to reset. You will see this as a slight flicker on the outputs. The only solution to this is to use a larger
power supply or heavier wires between the Lg-DMX/DC and power supply.
2) ! DMX-512 In/Out:
The two standard DMX-512 connections (‘data +’ and ‘data -’) are attached to these terminals, along
with (optionally) the wire shield. If there is a chance that the Lg-DMX/DC will not be powered up, then the it
is safest to also attach any downstream DMX-512 devices to the same set of terminals. In that way, an un-
powered Lg-DMX/DC won’t break the DMX-512 daisy chain.
If the wire runs are long, you may need to add a 120Ω (typically) termination resistor to the two ex-
treme ends of the DMX-512 daisy chain.
Gilderfluke & Co.• 205 South Flower Street • Burbank, California 91502 • 818/840-9484 • 800/776-5972 • fax 818/840-9485
Sd-50/xx Manual / September 10, 2012 9:58 AM / page 8 of 12