Roel Arits

Thank you for the nice compliment !

The current source use in the instructable has an exponential behaviour to compensate for the logarithmic perception or our eyes. When you use the triangular waveform to control the LEDs, the brightness of the LEDs will not fade in a linear wayAn LM317 can be used as a fixed constant current source by using its internal reference voltage of 1.25V, but i don't see how you would turn the LM317 into a variable current source in combination with the triangular waveform generator output.You could simply connect an NPN medium power transistor configured as an emitter follower to the output of the triangular waveform generator so you have a higher output power to drive LEDs directly.https://electronics.stackexchange.com/questions/251111/emitter-follower-led-circuit-led-in-collector-resistor-...

The current source use in the instructable has an exponential behaviour to compensate for the logarithmic perception or our eyes. When you use the triangular waveform to control the LEDs, the brightness of the LEDs will not fade in a linear wayAn LM317 can be used as a fixed constant current source by using its internal reference voltage of 1.25V, but i don't see how you would turn the LM317 into a variable current source in combination with the triangular waveform generator output.You could simply connect an NPN medium power transistor configured as an emitter follower to the output of the triangular waveform generator so you have a higher output power to drive LEDs directly.https://electronics.stackexchange.com/questions/251111/emitter-follower-led-circuit-led-in-collector-resistor-in-emitterThe next problem will be that the triangular waveform generator output does not swing from rail to rail. That means that the output does not go down to 0 volts, So if you want the LEDs to go off completely, you will need to bring the output voltage down with a couple of diodes in series or a zener diode.

Thanks kebmoore,RGB LEDs through white glass will also give a nice effect though. I tried that with "milky" white glass because that diffuses the light properly. But like you wrote : when the LEDs are off, you only see a white surface. On the other hand, that could be nice for a table or a surface where you don't expect that it suddenly gets coloured by RGB LEDs. F.e. : http://www.jimonlight.com/2009/06/15/64-rgb-led-ta...Cheers.