THE GEM - 1kW[Light&heatsource]

Max 85amp - featuring CREE X LAMP

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This is a PAR( Photosynthetically active radiation) project based on the high-current controller M4SUBDRV ( CREE XP-G3 LED is a very advanced light emitter (190 lumen/Watt). They have a huge µmol/watt output, but in order to drive these LED´s without a current limiting resistor, a closed loop system is mandatory. The M4SUBDRV inject current into 4 separate channels (40 amp MAX). The lamp will run of a 12v 500-1000W power supply. Peak 1kW * 190 ∞ 190.000 lumen

The goal of the project is to make a smart plant grow Raydiator, which controls the light intensity based on temperature sensor input (closed loop). By making the lamp output PWM and temperature controlled, the final capacity of the lamp depends on °C and by using Metal Core - Sinkpad PCB, the heat transfer from the individual LED is optimized. CC-BY-NC

Case: Imagine a part of your living space, where you can grow greens all year round, and at the same time use the heat-output to warm up your space. This could not only provide food all year, but also expand the outdoor season by starting sprouts indoor, in a controlled environment, before they are ready to be planted out. Why not just sow the seeds, you may ask. The reason for planting out the sprout, is to give it a competitive advantage, compared to unwanted plants. 

Another mayor benefit by utilizing the radiated heat, is the possibility to fully heat your living space with green energy. This means less foresting for wood to burn. Less Co2 emissions from NOT BURNING WOOD or other carbon-based energy sources. Naturally all this requires a solid environmentally friendly energy infrastructure.

By introducing CAN (Controller Area Network) to the "intelligent" GEM/lamps, if several lamps are connected only a "Master" CAN node will need a connection through either USB or wireless.  This means a great deal in a greenhouse scenario, where many lamps all need to be monitored and controlled from a central hub. Likewise only one wireless module in the network is necessary, depending on the case. 

UPDATE: The process of finding the best pcb for high current LED´s led me to Metal Core PCB with sinkpad´s. Sinkpad connects the cooling surface of the MCPCB and heat pad on the LED. This gives a x100 performance in heat transfer and thereby optimizing cooling. Literally the LED´s will be mounted more or less directly on the heatsink. The PCB´s has been ordered and I am making the final adjustments to the heatsink.  



The design is starting to manifest. 

White LED´s use energy to lite up the full visible spectrum. The Red and Blue only one wavelength(area) and  is therefore cooler in use. The difference  between the red and blue wavelength  is another matter. 

For a office environment, the fully white GEM will be more pleasant for the human eye.  In a school scenario the lamps will be part of  photon to plant growth experiment.

var [z]

  • REv 3 (Now 3 phase bldc driver w. brake resistor port)

    Juan-Antonio Søren E.P.06/13/2021 at 20:27 0 comments

  • The Dimmer Design Done

    Juan-Antonio Søren E.P.04/22/2021 at 16:41 0 comments

    The controller is now ready for testing. Have had to do a few changes to insure good system reliability. 

    * Since the controller can be used as a BLDC or stepper controller, I have upgraded the TVS diode package.

    * The 5V LDO have been upgraded to MSOP8 packgate (500mA continuus) from SOT 23-5 (only 200mA continuus).

    * Screw terminals has been upgraded to 3.5 pitch, which has a 17.5amp rating, thats 35 amp per phase (Continuus). Each terminal is rated to carry two conductors. This means 4 separate LED modules w. 4 channels can be powered/dimmed from a single controller. Do note that each half bridge is 60 amp rated. I would under no circumstance recommend to go beyond 1000WATT because of switching loss´s (depending on switching freq. and passive or active cooling).

    * Main power wire lugs has been upgraded to 85 amp rated from 65 amp rated. Do note that the lugs will get hot at 85 amp. The 65 amp lug can still be used. Wires can also be soldered directly on to the board, eg. if the controller should be integrated into a CNC routed heatsink/housing. 

    * Microchip (ATSAME51 MCU producer) advises to use a ferrite bead in series with the analog power domain supply, for some applications. This is to filter out digital noise before it hits the ADC/DAC. So I have chosen to follow their advice. The bead should be carefully chosen for DC filtering w. lowest possible resistance. 

    * Moved the 3 analog hall sensors, so that all 3 is aligned to center of rotation for NEMA23. For bigger steppers a 3D printed bracket can be used. 

    The 3 hall sensors highlighted in green placed to cover 30 degrees. The ADC (Analog to digital converter) of the SAME51 can make 1.000.000 samples per second. The MCU has two seperate ADC´s of which ADC0 is used for on board measurements (Not including A0/DAC which is broken out) Two pins on ADC1 is broken out for external use.  Pin functionality will be mapped in code. Broken out pins can also be regular IO/EXTINT.

  • IAUC60N04S6L030H

    Juan-Antonio Søren E.P.03/28/2021 at 12:24 0 comments


    Rev 2 Last minute change; upgraded to 40 V rated Bridges. Downgraded Sense resistor from 3W to 2W 2010 package.

  • Magnetic Decoder

    Juan-Antonio Søren E.P.03/28/2021 at 00:53 0 comments

  • REV_2

    Juan-Antonio Søren E.P.03/26/2021 at 13:48 0 comments

  • XP_G3_1Cj/W

    Juan-Antonio Søren E.P.03/14/2021 at 18:33 0 comments

  • Modular GROW LED

    Juan-Antonio Søren E.P.03/13/2021 at 18:43 0 comments

    Looking at the distribution of light across a given area, one advantage of LED´s, is the ability to spread out the light_source, to multiple sources. When looking at any grow light, the intensity and thereby umol/s/mm2 will be less at the perimeter of the beam. Compared to larger (500 LED´s x 5W) LED grow lights, The GEM will be  considerable smaller, but will have the advantage of a even distribution of photons.  By design, THE GEM can get closer to the canopy. By having the same LED count, that is on multiple GEM´s. The ability to micro manage each channel of LED´s is of course a mayor benefit. Networking each module, you can monitor and control variables like temp, cooling, power consumption and so on. 

    Using the USART connector, a Bluetooth Low Energy - Mesh network should be possible.

    Another advantage  of spreading out the  LED´s, over a larger area, is the fact that you can cool each module separately and thereby more efficiently.  

    The amount of light needed for any given crop is entirely dependent on your ambition regarding growth, power consumption, temperature of lamps, longevity of LED´s as a function of temperature, intensity and time. 


    Juan-Antonio Søren E.P.03/10/2021 at 10:29 0 comments

  • SILK

    Juan-Antonio Søren E.P.03/09/2021 at 18:55 0 comments


    Juan-Antonio Søren E.P.03/08/2021 at 23:24 0 comments

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