48 channel DMX dimmer pack (Version 2!) for LEDs and most solid-state relays (SSR)

This board is for sale!  Discontinued as of March 22 2011.  A limited quantity of used ones are available at a discount price.  See bottom of page for support information.
Board size: 3.5" x 4.0", with 4 holes for 6-32 screws; a set of 4 1/4" standoffs are provided.  There are 3 holes at the corners and one near the bottom right, at 2.49" x 0.16" relative to lower left corner.

Top view:
(top view)

Feature set of new Version 2:

(For existing customers looking for Version 1 information, go here).

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.  See wiring diagram below for details.

The basic operation is that this board switches the negative of your LEDs to the power supply's ground.  This is called low-side switching, and is the most common way things like this are done, since it is simpler, cheaper, and a little more efficient than switching the positive of the LEDs (called high-side switching). 

The wiring diagram is here.

Operation and testing:

  1. Turn off the LED power supply, and set the board DIPswitches to: Hires OFF, Testmode OFF, Terminate OFF.  Connect the power supply to the board.
  2. Turn on the LED power supply.  You should see the status LED blinking green slowly.  If not, check that at least 6V is present on the (+) relative to the (-).
  3. Turn off the LED power supply, and wire a LED: the LED anode goes to the power supply, and the LED cathode goes to the board, use channel 1.
  4. Turn on the LED power supply.  The status LED should blink slow green.  Now turn the Testmode to ON.  Your LED should fade up to 100%, then flash and go dark for a few seconds, and then repeat.  The status LED blinks red/green rapidly.  If your LED does not light, check the wiring and the LED polarity.
  5. At this time, you're ready to wire!  I don't have a good solution for how to combine all the LED anodes (+) together; you can use multiple wire-nuts, or get a multi-position terminal block and wire all its pins together, or strip 8" of wire and solder the LED anodes (+) to it.  I've done it all these ways and others.  If you've got something handy, please let me know.
  6. I suggest wiring a half dozen or so channels and verifying operation with the "Testmode" DIPswitch at this time.
  7. 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 three wires into the terminal block 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.
  8. 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 something is loose.  If it is slow green: no DMX is seen; double check the wiring, that pin 2 / pin 3 / GND is correct, and that your DMX source is outputting data.
  9. Now for the fun part: if the DMX start ID is 1, and your DMX source is outputting data for channel 1-48, you should be able to fade up and down your installed LEDs.  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

Price: $189 Discontinued March 22 2011.  A limited quantity of used ones are available at a discount price.
To my existing customers: thank you!  I will provide consulting & repairs as needed for the years to come.  If you need one or two more for some reason, please inquire.
To potential new customers:  unfortunately I am unable to produce these at a cost that makes economic sense.  If you have a large-scale project that these or a variation of the design would work for (i.e. qty 25 or more), please contact me.


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