LED DMX-512 lamp teardown

Here is a tear-down of 36W Par LED PAR CAN Stage Light with IR remote and DMX-512 control from wish.com sale. The light works well with DMX-512 control.

Front and back

On the back there are XLR3 DMX-512 connectors, address display and control buttons.

Look inside

On the left there is aluminum circuit board with LEDs. Going to right there is green main control board and power supply.

Control board main chips are 74HC595, MAX485 and unmarked IC that is possibly some MCU. The board seems to be designed for 12V power supply. The circuit board has three small FETs that drive the R, G and B LED control lines according to the controller chip controls. It seem that the LED board has just LEDs (and maybe resistors or other current limiters) and all the actual controlling is is done in the control board.

Power supply

There seems to be fuse F1 on the mains side. Y capacitor seems to be 2.2 nF (222) with 2 kV rating which should be decent but not dual isolation level. How well the transformer is isolated cannot be determined from outside.

Circuit board solder side seems to have decent clearly marked clearance between mains and low voltage side. This looks good.

This seems to be quite OK built device.

5 Comments

  1. Tomi Engdahl says:

    3KV test of cheap disco light with circuit analysis.
    https://www.youtube.com/watch?v=xyO4xq23zDs

    This light was generously sent by Aramus for our edutainment. It’s a classic eBay/aliexpress/amazon special and actually usable for some applications, but does have the usual hazards associated with cheap imported products.
    The unit is a very good demonstration of cost optimisation.

    The electrical separation and testing of these products is not up to Euro-American standards. If using them with other DMX lights I’d strongly recommend isolating them on their own buffer to avoid the risk of damage to other lights in the event that mains voltage finds its way onto the DMX network.
    As stand alone lights they have their uses. A single colour can be set by adjusting the RGB levels using the buttons on the back. To store each intensity setting you have to press “enter” before moving onto the next adjustment. If a colour is set and stored then the lights will automatically light in that colour at power up. The way they run the LEDs and the fact that they are all in series means that LED failure is almost guaranteed in regular use. But at the price they could be classed as disposable.
    As with many of these lights that cram too much functionality into a small processor, they have their limitations. They often rely on the DMX controller putting out a full 512 channel frame to allow time to process their effects after grabbing their channels of data. If the DMX is not what they were expecting they can sometimes glitch or not work at all.
    Many of the units are made by small manufacturers who buy components like cases and PCBs from other sources, so if you have 20 seemingly identical lights, some may have different software and behave differently.
    It’s not uncommon for lights like these to crash and glitch their memory settings resulting in data being spewed onto the DMX network causing a data conflict and knocking out an entire section of lights.

    The combined capacitive current leakage from a run of these lights could potentially give a strong shock from a network cable and affect operation of other lights.

    This light did pass a 3kV isolation test, but the construction of the transformer with low voltage windings laid directly across mains voltage windings is an issue. Ideally the transformers would be wound with double insulated wire or have sleeves where wires cross and extra separation tape.

    Reply
  2. Tomi Engdahl says:

    3KV test of cheap disco light with circuit analysis.
    https://www.youtube.com/watch?v=xyO4xq23zDs

    It’s a classic eBay/aliexpress/amazon special and actually usable for some applications, but does have the usual hazards associated with cheap imported products.
    The unit is a very good demonstration of cost optimisation.

    It is only really suited to small simple lighting rigs and not for a full theatre type application due to the low number of channels by modern standards

    The electrical separation and testing of these products is not up to Euro-American standards. If using them with other DMX lights I’d strongly recommend isolating them on their own buffer to avoid the risk of damage to other lights in the event that mains voltage finds its way onto the DMX network.
    As stand alone lights they have their uses. A single colour can be set by adjusting the RGB levels using the buttons on the back. To store each intensity setting you have to press “enter” before moving onto the next adjustment. If a colour is set and stored then the lights will automatically light in that colour at power up. The way they run the LEDs and the fact that they are all in series means that LED failure is almost guaranteed in regular use. But at the price they could be classed as disposable.
    As with many of these lights that cram too much functionality into a small processor, they have their limitations. They often rely on the DMX controller putting out a full 512 channel frame to allow time to process their effects after grabbing their channels of data. If the DMX is not what they were expecting they can sometimes glitch or not work at all.

    Many of the units are made by small manufacturers who buy components like cases and PCBs from other sources, so if you have 20 seemingly identical lights, some may have different software and behave differently.
    It’s not uncommon for lights like these to crash and glitch their memory settings resulting in data being spewed onto the DMX network causing a data conflict and knocking out an entire section of lights.

    The combined capacitive current leakage from a run of these lights could potentially give a strong shock from a network cable and affect operation of other lights.

    This light did pass a 3kV isolation test, but the construction of the transformer with low voltage windings laid directly across mains voltage windings is an issue. Ideally the transformers would be wound with double insulated wire or have sleeves where wires cross and extra separation tape.

    Reply
  3. Graeme says:

    How did you set the LC2412 to send all 512 channels?

    Thanks.

    Reply
  4. Graeme says:

    Thanks Tomi,

    The desk was in the video of the 3Kv test. I thought it was one of yours.

    Thanks either way.

    I use these for Halloween effects so have 10. They do the trick for me. I just need to get them working with a good DMX lighting console!!

    Reply

Leave a Comment

Your email address will not be published. Required fields are marked *

*

*