From an electrical point of view (I don't know how plants respond to flicker), there isn't really issue with ripple.
Lets assume that your LEDs needs to be driven at a constant current of 1000 mA. If your driver is rated at 1000 mA +/- 5%, it means that your LEDs will get 950-1050 mA. Is it a problem for LEDs rated at 1000 mA? Not at all. Many drivers run at 100+ kHz, which means that the human eye will never notice the flicker.
Essentially the drivers are build in this way:
AC --> DC --> Buck/Boost with the duty cycle varied according to the current measured with the current sense resistor (low voltage drop across).
Some (usually the better ones, like Phillips etc.) use IC's capable of converting straight from AC to constant current DC with very low loss.
Hmm...
I really do not know to what you mean when you say "ripple"...
Usually as "ripple" in the electronics world is meant the SUM of inductive noise ,
(because of bad grounding path => 'ground loops' or excessive wiring "twirling" around)
which is 'multiplied' in the output of a switching power supply (can be in whatever mode : buck,boost,buck-boost aka inverse/negative boost ,etc...) .
Thus making a "dirty " output ...
The whole ripple thing starts from the pwm regulation of the switching IC ...
A small ripple filter ( coil-capacitor ,LC ) before the output (20μΗ & 100nF ceramic/MKT/tantalum) will decrease at least x10 the ripple currents.
If that's the ripple you're talking about ....
A very easy way to make a CC driver ,delivering up to 3A and 37 Volts output (57 V for the HV version ) is using the IC : LM 2576/ LM2576 HV Simple Switcher Series from
TI ( ~4$ each IC ) .Very few other components are needed ( a storage coil ,a " free wheel "diode ,a pot ,few caps ...)..
To make it dimmable or even pulsed at higher voltages/currents ,you'll need an Arduino and a transistor or mosfet .(i.e BD 711...Switching on-off up to 12 Amperes,with minimal heatsink requirements ... Up to 5V at base ..Directly from Arduino's output..Even without resistor in between ...Can't get simpler ....)
Up to
1 Mhz frequency ...
A pot can set the Duty cycle from 0% up to 100% ....
EDIT:
Or the simpler way ...
Two ( of the CMOS type ,preferably ) LM555 timers (or a single "dual timer " LM55
6 IC ...),and
timing caps,resistors,and pots .(Timer A at astable operation-setting the pwm frequency - ,timer B at monostable operation ,
triggered by timer A -setting the pulse width aka duty cycle .And a power transistor/mosfet playing the role of the "switch" ...
.
Search "pwm circuits using LM 555 " for more info..
Seems complicated ,but ain't ....
......
.....
And a lot of great things start to happen ,then....
A total different world of driving the leds ....
A truly amazing world with lot's of things to discover ....
PS individual systems (both PS I & PS II ) ,at average ,photosynthesize approx at 4 Hz
per system ...
But ,who says that the systems are "sychronized",in their total sum ...?
So ,probably ,plants photosynthesize all the time ,continuously ....
No frequency there...
But "pulsed" leds ? ....
Ah...A great story,indeed...