We mentioned in various sections that product compatibility between LED dimmers and dimmable
drivers is the key to project success. Unfortunately, the only
sure-fire approach for project success involves actual and detailed compatibility tests before project deployment.
In many system-related lighting applications, it’s
not uncommon to encounter Contractors / Sub-Contractors that experience
colossal difficulty in the installation stage. It would be very stressful to
investigate on-site and revert installed devices. Thus, we strongly recommend
detailed tests before installing a project involving DALI control devices from
LED Driver Compatibility
To keep the discussion relevant to our products, let’s classify
compatibility tests in terms of dimmer-and-dimmable driver and dimmable
driver-and-LED light. We know there are two types of phase-cut dimming: leading-edge and trailing-edge phase-cut dimming. Before we need to confirm that both the dimmer and dimmable drivers operate on the same phase-cut
methodology before any meaningful
tests. Naturally, a trailing-edge dimmer works with a trailing-edge or both
leading / trailing-edge supportable dimmable drivers. It’s easy to understand
why a trailing-edge dimmer doesn’t work with a leading-edge dimmable driver.
If customers find no sensible result
when connecting a dimmer and a dimmable driver, we suggest them validating the
phase-cut methodology first. And they can easily do that by cross-testing the same
dimmable driver with a TRIAC light dimmer and a Trailing-edge LED dimmer. If
dimming restores after the TRIAC dimmer replacement, we have reason to believe
that the dimmable driver is TRIAC dimmable only. Due to cost constraints, not all dimmable LED drivers accept both leading-edge and trailing-edge phase-dimming methodologies. Some dimmable drivers only work with leading-edge dimmers.
In our experience, many dimmable LED
drivers for LED strips are TRIAC dimmable only; thus, they are not suitable for
trailing-edge dimmers. For LED strip dimming applications, we suggest our 1-10V dimming approach. Over time, the inrush surge and repetitive current
spikes at each zero-crossing points (100Hz for a 50Hz AC source) can become
problematic in consistency and lifespan.
Sometimes, it can be difficult to
judge the dimmer-and-dimmable driver compatibility by the limited product
description in the field. Therefore, to address the need for testing for
compatibility, we offer our dimmable lights as kit-set solutions to reduce the
time and effort for compatibility trials.
In practice, people often desire
dimmable downlights in the reading room or children's room. To do this,
customers can buy a new dimmable downlight or buy a dimmable driver to replace
the existing light (LED downlights usually have an external driver). For the
latter case, please refer to our application
notes about DIY matching a dimmable driver with an LED
downlight to get initial ideas.
In fact, to help explain about the product capability topics, we created several relevant LED dimming videos so interested prospects can understand further.
with LED MR16 Lamps
mentioned several times that product compatibility is one of the few technical
issues to investigate in lighting applications. We like to point out that incompatibility can also occur even without the presence of a dimmer.
Somewhat unique to LED MR16 or PAR 30 lamps is that as a
replacement of halogen lamps, these lighting fixtures require a transformer to
convert the mains voltage to the 12Vac for the light with an integral driver.
Historically, the 12Vac transformers are heavy and bulky magnetic coils that
light-weight electronic transformers had already replaced. Therefore, most
people would be replacing the halogen lamp with an LED MR16 lamp with the same
electronic transformer in a retrofit case. Interestingly, sometimes people find that a non-dimmable
LED MR16 lamp shows flickering, even when no dimmer is present.
these phenomena easily, we should point out that halogen lights are resistive
load, whereas LED lamps are not. Therefore, if the timing required to charge
the integral driver of the LED MR16 lamp does not meet that required by the 12Vac
ELV transformer operating under 50 / 60Hz cycle, flickering would occur. Again,
this phenomenon shows one of the incompatibilities found in LED lighting, even without
any dimming functionality involved.
Previously, we spent some time testing the performance of
different product combinations using our dimmer and SORAA® and other LED MR16 or PAR30 lamps. By holding the dimmer
and light unchanged, we see clearly that the dimming performance varies
significantly with different 12Vac transformers. Given the vast pool of other
products in the market to try, the trial-and-error-based experience can be
As SORAA® released its own brand 12Vac
transformer (TCVW-P-12-600-70-01-S3), we're glad to put behind such a trial-and-error approach for
compatibility issues among the products, at least partially. It's also great to
see the excellent deep dimmable performance using our dimmers and the SORAA® lamps together. This product strategy inspires us to work on our kit-set towards
an easier-to-use dimmable LED lighting solution.