3KV test of cheap disco light with circuit analysis.
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 Published On Mar 31, 2020

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. It took a lot longer to analyse than a better designed product because of the many tricks used to allow a small cheap processor to run the whole show. The software in these is a miracle of multitasking.
My lighting desk is a small unit used for testing. 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 (24). It has a very odd programming interface compared to many other desks and a lot of the people who hate it do so because they bought the wrong desk for an application or thought they'd just walk up to it and "run a show". That doesn't happen with ANY desk.
I find it useful for two specific reasons. It can instantly be set up as a two scene preset which is ideal for testing lights with a small number of control channels. It can also have scenes programmed in as a sequence and will then replay them at an adjustable speed, and most importantly boot straight into that mode at power up. That makes it useful for stand-alone applications.
It's manufactured by a company called Behringer who also make very interesting and affordable audiovisual stuff, but is hated by musicians who measure their ego in equipment cost and size.

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.

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