I think you are on the right track and I think I can do a better summary:
Goal: Order an kit to experiment with LED. Ebay has a nice 50W chip/dimming driver/heatsink/reflector/lens set at a reasonable price.
Notes: Kit is missing 120V plug (kind expected for international), kit includes thermal grease which will not hold the chip (recommend artic silver thermal adhesive), reflector and lens is damaged with cyano-adhesive (frag glue), the reflector has "pins" that looks to hold the assembly but are weak (best case they are alignment for a better cement (recommend a lens that uses screws (you can tap the heatsink if large or use screw into the heatsink fins))). Fans are noisy even at 12V bypassing the PWM control.
Bonus: Ordered as a two color chip hoping to do double duty.
Notes: The chip is all blue with half painted to become white. As the white still has a huge blue peak I should have gone for one color...
Bonus: Ordered dimmer with manual dimmer knobs (ie constant current).
Notes: the knobs have 10 turns total but only use the first one and only really work 50%-100%. A lack on indications make a par table difficult. A switch with two resistance values for hi/low may be better.
My conclusions:
For the simplest build use a single color cold white or 10,000-20,000K output with a power supply (fixed or set the resistance knob and forget). Burn like a metal halide (on/off for photo period for growth) and supplement with actinics to make the colors pop during evening viewing hours.
Slightly more complex: The two color chip with two channels is still VERY compelling to me as it is whites and supplements all in one. One driver can be used for multiple chips as long a parallel/serial is obeyed and you never run just one chip (double the current). So 2x two channel 50W only needs 2 drivers and not 4.
Slightly more complex II: the dimming drivers with the manual knobs opens up "tunable" color systems where you can fine tune the white/blue to get just the right color.
Way more complex: computer control is amazing with so many options and channels on modern controllers. Switch to PWM and a constant CURRENT power supply with multiple constant current drivers like the LDD series. These are failsafe as the cc driver can be picked so that the max current will never exceed a string (ie using 2x 700mA to drive each leg of a two color chip), you can dim to 0 vs the ~50% for knobs and build a true par table and have fun.
Like the post above I feel that 50W is a good size (1250 PAR at the water surface measured) and that the heatsink is acceptable for emergency passive cooling alone as i had a fan connection come loose and the heatsink was warm.
Goal: Order an kit to experiment with LED. Ebay has a nice 50W chip/dimming driver/heatsink/reflector/lens set at a reasonable price.
Notes: Kit is missing 120V plug (kind expected for international), kit includes thermal grease which will not hold the chip (recommend artic silver thermal adhesive), reflector and lens is damaged with cyano-adhesive (frag glue), the reflector has "pins" that looks to hold the assembly but are weak (best case they are alignment for a better cement (recommend a lens that uses screws (you can tap the heatsink if large or use screw into the heatsink fins))). Fans are noisy even at 12V bypassing the PWM control.
Bonus: Ordered as a two color chip hoping to do double duty.
Notes: The chip is all blue with half painted to become white. As the white still has a huge blue peak I should have gone for one color...
Bonus: Ordered dimmer with manual dimmer knobs (ie constant current).
Notes: the knobs have 10 turns total but only use the first one and only really work 50%-100%. A lack on indications make a par table difficult. A switch with two resistance values for hi/low may be better.
My conclusions:
For the simplest build use a single color cold white or 10,000-20,000K output with a power supply (fixed or set the resistance knob and forget). Burn like a metal halide (on/off for photo period for growth) and supplement with actinics to make the colors pop during evening viewing hours.
Slightly more complex: The two color chip with two channels is still VERY compelling to me as it is whites and supplements all in one. One driver can be used for multiple chips as long a parallel/serial is obeyed and you never run just one chip (double the current). So 2x two channel 50W only needs 2 drivers and not 4.
Slightly more complex II: the dimming drivers with the manual knobs opens up "tunable" color systems where you can fine tune the white/blue to get just the right color.
Way more complex: computer control is amazing with so many options and channels on modern controllers. Switch to PWM and a constant CURRENT power supply with multiple constant current drivers like the LDD series. These are failsafe as the cc driver can be picked so that the max current will never exceed a string (ie using 2x 700mA to drive each leg of a two color chip), you can dim to 0 vs the ~50% for knobs and build a true par table and have fun.
Like the post above I feel that 50W is a good size (1250 PAR at the water surface measured) and that the heatsink is acceptable for emergency passive cooling alone as i had a fan connection come loose and the heatsink was warm.
