Applications for Northlight DMX512 products.

Applications Page:

This page has information showing basic ways to use our DMX decoders and encoders for lighting and special effects.

Click here to see photos sent in by users.

Using Solid State Relays with Northlight Decoder Boards

Controlling Hobby Servos with 0-10 volts How to use the 8 and 24 channel decoders to control hobby servo's.	Analog encoding. Turning switches and sensors into DMX.
Simple Oscilloscope trigger circuit for DMX signals.	Light dimmer circuit wth 0 - 10 volt input.

Using Solid State Relays
Solid state relays suitable for this application feature low input current, zero crossing turn on, and low voltage(1 volt) dropout. Either SCR or TRIAC are suitable.
Random turn on are not recommended. This is strictly on/off. Not a lighting dimmer.

Acceptable types	Not acceptable
Crydom HD series HD6025 - HD60125 Crydom D series D1210 - D1240, D2410 - D2490 Opto 22 120D10 - 120D45 Opto 22 Z120D10 - Z120D45	Any Crydom with a -10 suffix D1210-10 ect. Any Crydom with an A prefix A2420 ect. Crydom CS CS2410 - CS2490 Opto 22 240D10 - 240D25 Any Opto 22 with an A in the number

Example circuit board for 8 solid state relays. Note this board showns the silk screen. To download an actual size 300 DPI scan of the board without the silkscreen, in PDF format, click on the image below. Also note this view is from the top looking through the board.
If you use LED's be sure they are low current type, 2 mA max current.

Photo with 8 channel decoder

Hobby Servo's
Turn DMX signals into mechanical motion.
Generally hobby servo's require a pulse having a variable width from 1 to 2 milli seconds, with 1.5mSec as the center position.
The schematic below is a simple voltage to pulse width circuit.

PARTS:
R1   100K OHMS 1/4 W                R2   47K OHMS 1/4 W
R3   33K OHMS 1/4 W                 R4   100K OHMS 1/4 W
R5   1K TRIM
D1   1N4148 / 914
C1   .22UF                                  C2   .01UF
IC1 LM555

It doesn't get more basic than this, all components are fairly common. The timer is set up to output a variable high pulse,1 to 2 MSec. and a long low pulse,20 MSec. Do not change the value of C1,R4. The trim pot is required.
The main draw back is that this circuit is not perfectly linear.

Analog encoding
Convert switches and sensors into DMX signals. Uses are found in Haunted houses, stage plays, themed events, holiday light animations, anytime you want to control DMX compatible equipment. Fog machines and strobe lights can be independly controlled be remote switches or sensors.
1. Use a wall wart transformer to power 8 switches and pots.
2. Use infrared remote to control effects.
3. Use infrared security sensor to control effects.

The schematic on thr right is a example of a analog board with 0 - 10 volt output. This basic example can work for relay input, just put the relay in between the pot and the op amp.

Light dimmer

This is a simple dimmer circuit that can be controlled with 0 - 10 VDC.
The schematic does not show the torroidal chokes necessary the prevent dimmer "buzz".
Oops, there was a mistake on the schematic. This is the corrected version. Sorry for any inconvience.

C lick here to download the schematic in PDF format.

Scope trig
This is a simple O'scope trigger circuit for checking DMX signals. It is based on a 4528 CMOS monostable multivibrator.
The "trigger" pot is adjusted first, untill a short pulse is generated near the end of the "BREAK" portion of the DMX signal. Then adjust the "delay" pot to zoom in on a portion of the signal. On DMX signals with few channels it works to trig the scope on the "trig" output, rather than the "delay" output.
This circuit will not work well on DMX signals where the "inter frame time" is as long or longer than the "break". This is a legal condition, but doesn't show up to often.
It is best to keep this circuit "floating" by powering it from a 9 volt battery and a 78L05 voltage regulator(not shown in schematic).

To download this Zipped schematic just click on it.

Photos sent in by users:

Encode32 installed in an Arri board, La Coruna Spain.

Lots of room for the extra transformer and board.

This board is in good condition, just right for an upgrade to DMX.

Close up of the installed board.