SimACo – LED lighting

In nowadays more and more aquariums have LED lighting – lighting with light emitting diodes. LEDs help to reduce current consumption, this reduces your bills for electricity. But there are more useful aspects of LEDs. With diodes you can far better select the spectrum of light than with fluorescent, incandescent or metal halide lamps. Aquarium plants mostly needs blue and red light. So aquarium owner can mount in to the aquarium hood white, red and blue LEDs. White LEDs will be for the general aquarium appearance, blue and red LEDs will be useful for the plants. And here comes one more good property of LED lighting: they can be dimmed. It means that LED brightness can be adjusted from 0 to 100 percents. With dimming you can achieve practically unlimited lighting possibilities. You can reduce or increase each color’s brightness and that way achieve more different colors. SimACo for that purpose has four separate channels. So four chains of LEDs with different colors can be connected to SimACo. With SimACo in Manual mode you can adjust each color’s brightness whenever you want. Auto mode has even bigger possibilities: you can in small steps increase or decrease brightness of each color during selected interval of time. For example: you woke up at 7:45 o’clock in the morning. You want to make such regimes: sunrise imitation – full brightness eight hours – sunset imitation – moonlight imitation during night. You can set channel of red LEDs to reduce their brightness from 8 hour (100% brightness) to 18 hour (50%). So you set such time intervals (press to enlarge):

Aquarium controller events example

Table shows possible LED lighting configuration.
All LEDs must be connected to power supply through additional devices, called drivers. Driver is needed for two purposes: it supplies constant voltage/current to LEDs circuit and allows to dim LED lighting. Manufacturers make several types of drivers: without control, PWM controlled, DC voltage 0-10V controlled, controlled using resistance, controlled using triac and mixed type. SimACo generates 3.3V PWM signal for LEDs control, so driver must have inbuilt PWM control an accept 3.3V voltage level. SimACo has two LED driver boards: MOSFET driver board and Mean Well LDD-H drivers board. Each board has four channels.

  • MOSFET driver board is designed to be used with LED strips or LED modules which requires constant voltage 12V or 24V power supply. Board gets 12V for internal components from the main board; also you need to connect external 12-24V power supply unit (PSU) for the LEDs. Board output voltage to LEDs will be equal to the PSU voltage. Electrically channels #1 and #2 are connected through one common fuse FU1 in the board; channels #3 and #4 are connected through fuse FU2. So total current for channel #1 plus channel #2 can not exceed 4A; the same rule applies to the channels #3 plus #4. Total current for all four channels can not exceed 8A.
    LED module LED strip

    MOSFET driver board v.2.1

  • LDD driver board has four Mean Well LDD-XXXX series drivers soldered in. Board must be used with LEDs which requires constant current power supply. This board mostly can be used with powerful LED (1-3W) strings, connected in series or COB LEDs. COB mostly requires about 36V power supply.
LED module with heatsink COB LED

LDD-H driver board v.1.1

Mean Well LDD-XXXX series drivers


According to the manufacturer, LDD-XXXH series drivers have such features:

  • DC/DC step-down converter
  • Input voltage: 9 ~ 56VDC for LDD-300H…1000H drivers and 9 ~ 52V for LDD-1200H, LDD-1500H drivers
  • Output LED string voltage: 2 ~ 52VDC for LDD-300H…1000H drivers and 2 ~ 46V for LDD-1200H, LDD-1500H drivers
  • High efficiency up to 97%
  • Built-in EMI filter, comply with EN5 5015 and FCC part 15 without additional input filter and capacitors
  • Built-in PWM and remote ON/OFF control
  • Protections: Short circuit / Over temperature
  • Cooling by free air convection
  • Compact size
  • Low cost, high reliability
  • Fully encapsulated with IP67 level for pin and wire style

MOSFET and LDD driver boards both connects directly to the main board. Also additional power supply is required for both boards to supply power to the LEDs. Power supply voltage and current must be selected according to the selected LED lighting type, voltage and consumed current. If you already have complete LED lighting system which is fed from the wall socket, then you can connect it to the any DEVICE1-DEVICE8 outlets. But then you will lose ability to control LED brightness using controller and you will only have the ability to switch your LEDs OFF or ON at the time, set by you.

All LEDs will loose their light output during life time. The lifetime of a LED module is defined as the time it takes until its light output, or lumen maintenance, reaches 70% of the initial output. Lifetime hardly depends on LED crystal working temperature. Those two variables are inversely proportional: high temperature means short life time and vice versa. Below is the graph which illustrates how life time vs temperature dependency:
There is no a temperature threshold below which LEDs will serve forever and their light output will remain stable. So you must keep LEDs as cool as possible. For this purpose LED temperature sensor can be connected to the controller. Sensor is based on NTC thermistor. It has metal lug with 4,2mm hole, so sensor can be attached to LED radiator with a screw. Sensor will measure LED radiator temperature. Controller can generate alarm when LED temperature is too high. User can adjust alarm temperature threshold level from 30°C to 95°C. Also controller can activate LED radiator fan when radiator temperature becomes to high. User can adjust desired temperature level from from 30°C to 95°C.