With rising energy and electricity prices, particularly in regions like Europe, the demand for energy-efficient solutions has soared. One of the most effective methods to achieve this is through AstroDIM, a built-in timer dimming function. AstroDIM directly addresses this need, offering a simple, effective, and adaptable approach to smart road lighting and smart cities.
This innovative lighting control technology enables autonomous night-time dimming, typically with five independent dimming levels (Astro, time mode), all without the need for complex external control infrastructure. The YW602 zhaga plug in controller with AstroDim determine the “theoretical midnight,” ensuring smooth and virtually imperceptible transitions between dimming levels.
Why choose Timer Dimming (AstroDIM)?
Have you ever noticed streetlights blazing at full brightness in the dead of night, when traffic and pedestrian activity are minimal? It’s a clear indicator of inefficiency. Most citizens are asleep during these hours, with only a fraction of night-time workers and travelers on the roads.
For those in the LED street lighting industry, the EN13201 standard provides valuable guidance: as traffic volume decreases and road conditions simplify, lighting requirements—including illumination and uniformity—can be relaxed. This allows for a strategic reduction in the power of streetlights, thereby lowering brightness, illuminance, and uniformity.
The adoption of astronomical clock dimming technology offers compelling advantages:
Optimized Road Lighting: Even with reduced traffic and pedestrian flow in the middle of the night, road lighting can still meet all relevant safety and visibility requirements.
Significant Energy Savings: By strategically reducing the output power of lamps during low-activity periods, energy consumption is effectively minimized, leading to substantial cost reductions.
Fostering Green and Smart Cities: Timer dimming goes beyond simple energy conservation. It makes urban lighting far more intelligent, moving away from constant full-power operation. This directly contributes to the creation of more sustainable and smarter urban environments.
Extended Lamp Life: Operating LED lights and their power supplies at lower temperatures for a portion of the night reduces strain and heat buildup, which in turn helps to significantly extend the overall lifespan of the lighting fixtures.
Fostering Green and Smart Cities: Timing dimming goes beyond mere energy conservation. It makes urban lighting more intelligent, moving away from constant full-power operation. This contributes to the creation of more sustainable and smarter urban environments.
Extended Lamp Life: Operating LED lights and their power supplies at lower temperatures for a portion of the night reduces strain and heat build-up, which in turn helps to extend the overall lifespan of the lighting fixtures.
Different astronomical time clock is implemented by LED driver manufacturers and smart street lighting controller suppliers, such as Osram, Philips, Tridonic, Inventronics, Meanwell etc. Let’s explore some typical implementations.
Philips / Osram AstroDIM Function (Dynadimmer & AstroDIM)
Both Philips and Osram LED drivers incorporate timer dimming, with Philips branding it “Dynadimmer” and Osram calling it “AstroDIM.” These features allow the fixture’s brightness to be adjusted at specific times throughout the night. Their dimming curves can be configured across five distinct time periods (T1 to T5), with programmed dimming levels and smooth transition gradients for each.
A key characteristic of Dynadimmer and AstroDIM is their lack of a built-in clock. Instead, they calculate time based on a “midnight point,” which is the midpoint of the operating duration between power-on and power-off. These systems require two consecutive nights to verify consistency in run duration (less than 15 minutes variation) before making adjustments to the dimming curve on the third night.
For example: If the previous run time was 8 hours, the system calculates the current power-on time as 20:00 (8 PM) and the power-off time as 04:00 (4 AM). If the previous run time was 6 hours, the power-on time becomes 21:00 (9 PM) and the power-off time 03:00 (3 AM). The dimming operation then proceeds according to the established dimming curve timetable.
Note: The calculated “virtual midnight” at 24:00 doesn’t always align perfectly with actual midnight.
Inventronics AstroDIM Function (Self-Adapting Midnight & Percentage)
Inventronics, founded in 2007 and specializing in high-efficiency LED power supplies, offers its own AstroDIM logic with “Self Adapting-Midnight” and “Self Adapting-Percentage” options.
“Self Adapting-Midnight” closely resembles the timer dimming functions of Osram or Philips. Consider a dimming curve of 100% for 6 hours, 70% for 1 hour, 50% for 4 hours, and 70% for 3 hours. If the lamp turns on at 5:00 PM, it will initially follow this curve. However, if it starts getting dark at 6:00 PM in the summer, the AstroDIM streetlight with Self Adapting-Midnight will adjust. It will operate at 100% for the first 5 hours, 70% for the next 1 hour, 50% for the next 4 hours, and 70% for the last 2 hours. This ensures that the run time of the two time periods before and after midnight remains constant, while the first and fourth time periods are each reduced by 1 hour to account for a shorter total running time (e.g., 12 hours in summer). This adaptive feature cleverly accounts for seasonal changes in daylight hours.
“Self Adapting-Percentage” offers a similar adaptive function. Instead of adjusting specific time periods, it proportionally reduces each of the four time periods (e.g., to 86% of the original, based on a 12/14 winter-to-summer change) to run the dimming curve. This differs from the “Self Adapting-Midnight” approach, which reduces specific time periods.
Meanwell AstroDIM Function
Meanwell provides detailed descriptions of its timing dimming capabilities. For instance, their ELG series allows for customized dimming curves. A common curve might involve 100% brightness for the first 6 hours after activation, then 70% for the next 1 hour, 50% for the following 4 hours, and finally 70% for the last 3 hours.
For example: If the lamp activates at 5 PM, it would follow this schedule:
5:00 PM: 100% brightness
11:00 PM (6 hours after turn-on): Switches to 70%.
0:00 AM (7 hours after turn-on): Switches to 50%.
4:00 AM (11 hours after turn-on): Switches to 70%.
7:00 AM (14 hours after turn-on): Constant current level maintained until deactivation
