32 channel DMX dimmer "pack" for LEDs/clusters/strips/bars (or
relays,
solenoids,
small motors, anything DC powered)
(New version 2!)
This
board is for sale!
Board size: 6.95" x 3.0", with 6 holes for 6-32 screws; a set of 6 1/4"
nylon standoffs are provided. There are
4 holes at the corners (0.15" in from board edges) and two near the
middle, at 3.6" x 1.5" and 5.1" x 1.5"
relative to lower left corner.
Top view:

(for Version 1 information, please go here)
Feature set:
- 32 channels with one
board! No more compromises due
to not having as many channels as you really want. If you're
tired of the expense and hassle of wiring multiple 3-channel dimmers to
get even a modest number of channels in your installations, this board
is for you. Example: you can run 10
separate RGB flex strips or ropelight with smooth, precise, DMX
controlled color mixing with one
board.
- Each channel can switch 8 Amps,
total
current capability of the board is at
least 40 Amps
continuous, and up to 70 amps, depending on installation specifics.
- Each channel can switch up to
48V
for driving large clusters of
LEDs efficiently.
- Each channel diode protected from inductive load switching
spikes, making it safe to use with solenoids, relays, small motors, and
unusual stuff.
- Fully (power and signal)
isolated DMX input,
using the marvelous and not cheap
Maxim MAX1480 isolated RS485 transceiver.
- 4096 levels of dimming at
a pulse-width-modulation (PWM) refresh
rate of 450Hz (can be 112Hz to
7Khz by request). This
allows smooth fade up & down from black with no flicker
ever! Unlike cheap stuff that doesn't even have specifications,
this board was specifically designed for theatre-quality dimming that
can be photographed or video recorded without flicker.
- LED brightness levels retained if DMX signal is lost.
- DMX start channel (1-511) set via DIP switch, changes are
immediate, status LED blinks orange to acknowledge
setting change.
- DMX termination on/off via DIP switch. No jumpers or plugs
to deal with!
- Dimming enabled on all channels yes/no via DIP switch to protect
non-dimmable loads
from damage (relays, solenoids, etc.).
- Test pattern via DIPswitch: fade up all channels to 10%, then
chase all channels, then repeat. Very handy
for
debugging installations.
- High-resolution (16-bit) DMX input mode, selectable by DIP
switch, for ultimate precise brightness control.
- Supports the top speed possible with DMX: 512 channel frames @
44fps. No having to set a max fps rate, or a delay between
frames, or any other hacks some other DMX devices require.
- Multicolor status LED indicates DMX protocol or wiring error
(red), no DMX wire connected / no data on connection
(green slow blink), and valid DMX frames incoming (green fast blink).
- LED connection headers are a unique "pluggable" design: they can
be unplugged
from the board, wires added/removed, then plugged back in. They
can be plugged in two ways: such that the wires exit parallel to the
board, the conventional case (shown in picture) or straight up out of
the
board. This allows for much easier installation and for moving
installations, since the board and the LED clusters are easily
separated.
- Board electronics runs from 7-48V DC, using the same power supply
as your LEDs. At 12V the current draw is approximately 100mA.
- Up to 16 boards can run from a single DMX source, so a complete
DMX
universe of 512 high-current channels can be easily built.
Since this board is intended to be installed in an enclosure with other
equipment, and wiring requirements are highly dependent on the
installation, there is
no case provided and the DMX connection is with a terminal block
instead
of a bulky 3 or 5-pin XLR (either is available by request). See
wiring diagram below for details.
The basic operation is that this board switches the negative of your LED clusters to
the LED power supply's ground. This slightly counter-intuitive
method is called low-side switching,
and is the most common way things like this are done, since it is
simpler, cheaper, and more efficient than switching the
positive of the LED clusters (called high-side switching).
The wiring diagram: is here.
Some notes about the wiring:
- LED cluster positives are
all
tied together with thick wire to the positive of the power supply
for the LEDs (up
to 48V).
- LED cluster negative goes
to
terminal block. This can be a
thinner wire, since only the current for that cluster goes down it (up
to 8 amps).
- LED power supply goes to LED power terminal block (the large one
on the right). The positive can be a thin wire since this is only
used
for powering the board and diode inductive switching protection.
The negative(s) needs
to be thick wire, since the current for all the LED clusters goes through
these
wires. For 10 amps or less total, a single negative connection is
fine. For 10-20amps total, two are needed, and 3
recommended. For above 20amps all four are required. The
power supply should be located as close to the board as possible.
- NOTE: this board doesn't do any current limiting. When it
switches a cluster on (i.e. the cluster's negative is switched to
ground) the effective resistance of that switch is less than a tenth of an ohm. Therefore
the LED cluster has to be designed to limit current to whatever the
LEDs are rated for. Fuses can also be added. I am happy
to advise on LED cluster designs.
Operation and testing:
- Turn off the LED power supply, and set the board DIPswitches to:
Dimmable ON, 16bit DMX OFF, Testmode OFF, Terminate OFF.
- Connect the LED power supply to the board. (+)
is the top position on the 3-position connector on the right, marked
with red paint. (-) is either of the two below it, and either of
the two on the 2-position connector in the middle of the board.
- Turn on the LED power supply. You should see the status LED blinking
green slowly. If not, check that at least 7V is present on
the (+) relative to the (-).
- Now connect the (+) for one of your LED clusters/strips to LED
power supply + and the (-) to the power supply negative. It
should light up. This ensures it is working.
- Turn off the LED power supply, and wire the cluster in: the LED
cluster (+) goes to the LED power supply (+), either at the big green
board connector or at the power supply itself. Wire the LED
cluster (-) to channel 1.
- Turn on the LED power supply. The board's status LED should
again blink green slowly, and the cluster is off. Now flip the
"Testmode" DIPswitch to ON. The status LED now toggles red &
green rapidly. The LED cluster
should fade up from black to 10%, then flash full-on momentarily, then
go off. After 5 seconds or so this repeats. The
board is doing a fade-up of all channels to 10%, then chases all
channels at 100%, then repeats. If the LED cluster doesn't light,
or stays lit, turn off power and recheck wiring. Also try a
different channel.
- At this time, you're ready to
wire! I don't have a good solution for how to combine all
the LED cluster (+) together; you can use multiple wire-nuts, or get a
multi-position terminal block and wire all its pins together, or strip
8" of thick wire and solder the LED cluster (+) to it. I've done
it all these ways and others. If you've got something handy,
please let me know.
- I suggest wiring a half dozen or so channels and verifying
operation with the "Testmode" DIPswitch at this time. They should
all come up to 10%, then chase. Remember that multiple thick,
short wires from the board to the LED power supply ground are required
for high currents; see notes and wiring diagram above.
- On to DMX: set the "Testmode" DIPswitch to OFF, choose the DMX
start ID (suggest 1) and set the
9-position DIPswitch for it (for help with decimal to binary go here),
and
connect the DMX cable to the board. If you have a 3-pin or
5-pin DMX cable, you can cut the end and screw the wires into the
terminal block (pin 2 and pin 3; pin 1 do not connect) or use a 3 or 5
pin to wire pigtails adapter - I normally have a few for $15.
Either of the two DMX terminal blocks can be used, there are two for
wiring convenience for multi-board installations. Top pin is DMX
pin 2, bottom pin is DMX pin 3.
- Flip the "Terminate" switch to ON, and plug into your DMX source
and turn it on. The board status LED should be flashing fast
green. If it is red (meaning garbled data): the pin 2 / pin 3 is
likely backwards or one is loose. If it is slow green: no DMX is
seen; double check the wiring, and that pin 2 / pin 3 is correct, and
that your DMX source is outputting data.
- Now for the fun part: if
the DMX start ID is 1, and your DMX source is outputting data for
channel 1-32, you should be able to fade
up
and down your installed LED clusters. If there is a lot
of flicker, check the DMX wiring; if one wire is loose there will be
lots of bad data. If the fade up/down looks choppy, compare it
with the fade up the Testmode does. Some lighting control desks
and software don't do smooth ramps; the fade up the Testmode does shows
the board's best capabilities.
Other notes:
- DMX requires that the last (and only the last) DMX device in a
network be terminated; please look elsewhere for more details about
this. The "Terminate" DIPswitch accomplishes this.
- The "Dimmable" DIPswitch is normally ON. For special
devices that can't or shouldn't be dimmed, turn this OFF. Now if
the DMX brightness value for a channel is 0, the device is off, and for
1-255 it is fully ON.
- The "16 bit DMX" DIPswitch is normally OFF. For finest
dimming control possible (such as from a computer) this can be turned
ON, and the board combines two DMX channels (8bits & 8bits) to
create one 16-bit dimming channel so you can set the brightness to 4096
different levels.
Price:
$259, plus sales tax if
shipped to a California address.
Rush
orders can be accommodated; just ask. Price is 10% off for
quantity 4 to 8, 15% for quantity 9-15. For larger quantity,
customization (need built in patterns? On/off with a
pushbutton? The status LED on leads?), or even substantial design
variation please inquire. This is what I do for a living.
Since shipping costs vary widely depending on method and destination
and I'd like to know the details of your installation before any sale
there isn't
a "shopping cart" here. I will send an invoice via Paypal.
Paypal takes credit cards.
Please note: For PayPal, a
3.5%
processing fee will be added to the total, to cover their fees.
This can
be avoided by sending a check.
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