A few months ago I wanted to make a dimmable constant current led driver and ask about it in this thread.
In the mean time I bought a 2.2Amp driver from Meanwell with external dimming option. The LEDs use 42V supply and the driver supplies 42V. Output current is dimmable with external pot, pwm or 0-10v voltage.
I have opted for pot, and made another circuit that has six switches for six differnt lights, and six bi-color leds that show state of every lamp. Led supply voltage is sunken by a 1W resistor for every led to about 2V, and there lies a new problem. The circuit works fine for last four months, but resistor temperatures give me an uneasy feeling. I get about 90 deg C on all the resistors and now I would like a suggestion for ver. 2 of the same circuit.
The only solution that I came to is to find a voltage stabilizer that accepts 42V on high side and to add separate lines for led supply with smaller resistors that are applicable for approx 3v sinking. Then to add a massive heat sink to the stabilizer.
Option B:
I am thinking about remodeling it all. I have an Arduino dev board and I have made some simple programs with it. I am thinking about making an Arduino based control circuit. Advantage of it would be, to enable it for house automation, for a situation when I master the use of ethernet shield, so I can control all of the functions from local web location.
In that case, I could use a pwm output for dimming control. But, there rise many other questions about how to connect hardware for other controls and how to power it all. There are six 12W led downlights with intended on/off functions. The driver is powered by one AC line with a switch on a wall. There are also four fluorescent lamps that are now connected to second AC line with second switch on the wall.
Best scenario that I came to is to connect power for the Arduino board to one AC line, and all the light sources to the other AC line. Now I would need to isolate the AC switching functions from the Arduino. Is this task better served with an optical insulator (optocoupler) and a FET or is it better to use a mechanical relay with some transistor as Arduino output signal amplifier?
There will I need four output circuits for fluorescent AC lamps, one for AC of the led driver, six for the individual LED lamps, one PWM and a four for multiplexed inputs from 13 switches. Here is another question, can I use multiplex for outputs in the same way I can use it for inputs? What would be a good 16/4 or 8/3 multiplex ic for this use? I am thinking about multiplexers because I think that I get out of free i/o lines.
Should I add some protection elements (fuses) in the circuit and where? On AC input to Arduino power supply should be a fuse, right? What about dc lines, should I plan protection there too?
I would like to hear your suggestions on my ideas.
Thank you all for your time and sorry for a longer post, I tried to be as detailed as possible.
Regards,
Sasa
In the mean time I bought a 2.2Amp driver from Meanwell with external dimming option. The LEDs use 42V supply and the driver supplies 42V. Output current is dimmable with external pot, pwm or 0-10v voltage.
I have opted for pot, and made another circuit that has six switches for six differnt lights, and six bi-color leds that show state of every lamp. Led supply voltage is sunken by a 1W resistor for every led to about 2V, and there lies a new problem. The circuit works fine for last four months, but resistor temperatures give me an uneasy feeling. I get about 90 deg C on all the resistors and now I would like a suggestion for ver. 2 of the same circuit.
The only solution that I came to is to find a voltage stabilizer that accepts 42V on high side and to add separate lines for led supply with smaller resistors that are applicable for approx 3v sinking. Then to add a massive heat sink to the stabilizer.
Option B:
I am thinking about remodeling it all. I have an Arduino dev board and I have made some simple programs with it. I am thinking about making an Arduino based control circuit. Advantage of it would be, to enable it for house automation, for a situation when I master the use of ethernet shield, so I can control all of the functions from local web location.
In that case, I could use a pwm output for dimming control. But, there rise many other questions about how to connect hardware for other controls and how to power it all. There are six 12W led downlights with intended on/off functions. The driver is powered by one AC line with a switch on a wall. There are also four fluorescent lamps that are now connected to second AC line with second switch on the wall.
Best scenario that I came to is to connect power for the Arduino board to one AC line, and all the light sources to the other AC line. Now I would need to isolate the AC switching functions from the Arduino. Is this task better served with an optical insulator (optocoupler) and a FET or is it better to use a mechanical relay with some transistor as Arduino output signal amplifier?
There will I need four output circuits for fluorescent AC lamps, one for AC of the led driver, six for the individual LED lamps, one PWM and a four for multiplexed inputs from 13 switches. Here is another question, can I use multiplex for outputs in the same way I can use it for inputs? What would be a good 16/4 or 8/3 multiplex ic for this use? I am thinking about multiplexers because I think that I get out of free i/o lines.
Should I add some protection elements (fuses) in the circuit and where? On AC input to Arduino power supply should be a fuse, right? What about dc lines, should I plan protection there too?
I would like to hear your suggestions on my ideas.
Thank you all for your time and sorry for a longer post, I tried to be as detailed as possible.
Regards,
Sasa
Comment