Steve K
Flashlight Enthusiast
hi gang,
Part of my background is that I've had the pleasure of designing a "peak power tracker" (a.k.a. max power point tracker, or MPPT) for solar panel applications. I was poking around and found this MPPT chip from ST Micro, the SPV1020:
http://www.st.com/internet/analog/product/250769.jsp
The function of a MPPT is to adjust the load applied to a solar panel in order to maximize the power extracted. This is needed because the max voltage and current of the panel will change with the amount of light shining on it and the temperature (and age, etc.)
Naturally... it occurred to me long ago that bike dynamos could use a MPPT too. The problem is that the implementation can be tricky/expensive/bulky. The SPV1020 looks like it might have the potential for application on bike dynamo lights, although I don't know how expensive it would be. The eval board does look a bit bulky.
My own attempt at a limited MPPT simply switches the load between two LEDs and 4 LEDs at a fixed speed.
http://www.flickr.com/photos/kurtsj00/5420960597/in/set-72157621965148305
Has anyone else built a MPPT or other circuit that tries to adjust the load in order to maximize the power extracted from the dynamo as the bike's speed changes or as the load changes? If I recall correctly, Martin's circuit does some adaptation to speed, but don't recall how. Are there other examples? (and I'll mention that my own circuit was an adaptation of a circuit by CPF's own Bandgap).
regards,
Steve K.
Part of my background is that I've had the pleasure of designing a "peak power tracker" (a.k.a. max power point tracker, or MPPT) for solar panel applications. I was poking around and found this MPPT chip from ST Micro, the SPV1020:
http://www.st.com/internet/analog/product/250769.jsp
The function of a MPPT is to adjust the load applied to a solar panel in order to maximize the power extracted. This is needed because the max voltage and current of the panel will change with the amount of light shining on it and the temperature (and age, etc.)
Naturally... it occurred to me long ago that bike dynamos could use a MPPT too. The problem is that the implementation can be tricky/expensive/bulky. The SPV1020 looks like it might have the potential for application on bike dynamo lights, although I don't know how expensive it would be. The eval board does look a bit bulky.
My own attempt at a limited MPPT simply switches the load between two LEDs and 4 LEDs at a fixed speed.
http://www.flickr.com/photos/kurtsj00/5420960597/in/set-72157621965148305
Has anyone else built a MPPT or other circuit that tries to adjust the load in order to maximize the power extracted from the dynamo as the bike's speed changes or as the load changes? If I recall correctly, Martin's circuit does some adaptation to speed, but don't recall how. Are there other examples? (and I'll mention that my own circuit was an adaptation of a circuit by CPF's own Bandgap).
regards,
Steve K.