raschemmel:
I really don't know why you don't re-think your design criteria so that you can decide whenever you want to exactly how many
700mA LEDS are enabled or make the intensity VARIABLE so you can dim it as much as you want or crank it up if you want to cook flies. It's really up to you, not us. Besides, it's on somebody else's dime , right ? Tell us what you need for the ideal setup and we'll see what we can cook up. You need to take a more command of the situation and simply say something like:
"This is an experiment . We don't know how much red light we need to wake the fly-brain response and we want to be scientific about it so we don't want to just BLAST THEM TO KINGDOM COME with red light right off the bat. We want to start small and say for example.;
The date is blah blah, The time is blah blah. Commencing Operation Flybrain now.
Initial setting is xxxx lumens (or Watts) .
The date is blah blah, The time is blah blah. Observations; No RESPONSE
Increasing RED-ZONE GENERATOR to xxxx Watts
The date is blah blah, The time is blah blah. Observations; No RESPONSE
Increasing RED-ZONE GENERATOR to xxxx Watts
The date is blah blah, The time is blah blah. Observations; No RESPONSE
Increasing RED-ZONE GENERATOR to xxxx Watts
The date is blah blah, The time is blah blah. Observations; No RESPONSE
Increasing RED-ZONE GENERATOR to xxxx Watts
get the idea ?
There are a number of ways to do this.
Crossroads probably knows them all. I have a few ideas.
Simple approach
Variable power supply
Multiple BANKS
Each BANK contains X number of 700mA LEDS
Each LED of EACH bank can be individually enabled with a physical switch or a computer signal (your choice;, physical is cheaper)
Each BANK can be individually ENABLED.
Result at any moment , you can select EXACTLY how many LEDS are ENABLED
AND
You can select the intensity of the ENTIRE ARRAY using the MASTER INTENSITY KNOB (which could be nothing more that a potentiometer read by an analog port which tells the computer what duty cycle to set for the LED PWM drive signal using the
MAP function to map the analog pot value to the PWM duty cycle so midway on the pot is 50% duty cycle , full CCW is close to ZERO (or=0) and full CW is MAXIMUM DUTY CYCLE , ergo MAXIMUM POWER.
So when the flybrain response becomes ACTIVE , you can say, "Based on our data, the response is triggered when we apply YYY
Watts (it would be much better if we can find a light sensor that works with that band of the light spectrum so you can say YYY
LUMENS)
Cool~!
What I need is to create a ~5mW/mm^2 illumination on ~400 flies trapped in plastic vials, for continuous-pulsatile adjustable mode. I don't want to control each of LEDs separately. They are supposed to turn on/off at the same time. For the apparatus that we are building, the distance from LED array to flies is also adjustable with a range from 1 inch to 3 inches. Please let me know if I should provide more information. Many Thanks~~