The dynamo LED driver circuit that has been discussed in this thread has matured and a PCB is available to help those who'd like to build it.
The following power curves have been achieved with a hub dynamo and this driver:
This is the circuit:
The hardware looks like this (ecaps C1..C5 are located off the board):
and it fits into a 1 1/8" steerer tube (C1..C4 went into the tube first, C5 resides inside the headlamp assembly):
The PCB is single-sided, FR4, intended to be hand-assembled, 100% thru-hole components (zero SMD).
All parts are standard and the key components are LM2907 analog IC and IRFD024 / IRFD9024 HEXFETs.
The source files of the design are here. Contains BOMs for both hub and bottle type dynamo application.
I'm going to have some of these PCBs made and want to ask around who would like some.
Please post in this thread how many you like, if you plan to use them for hub or bottle type dynamo, how many LEDs you plan to connect, what country you want them shipped to.
I estimate one of the PCBs will cost no more than EUR 5 (w/o components and assembly) plus a bit for shipping, but not sure abt the exact cost right now.
Update: Cost of my current stock is EUR 3.80 per PCB, plus shipping by letter. If you like one of these PCBs, please PM me.
The following power curves have been achieved with a hub dynamo and this driver:
This is the circuit:
The hardware looks like this (ecaps C1..C5 are located off the board):
and it fits into a 1 1/8" steerer tube (C1..C4 went into the tube first, C5 resides inside the headlamp assembly):
The PCB is single-sided, FR4, intended to be hand-assembled, 100% thru-hole components (zero SMD).
All parts are standard and the key components are LM2907 analog IC and IRFD024 / IRFD9024 HEXFETs.
The source files of the design are here. Contains BOMs for both hub and bottle type dynamo application.
I'm going to have some of these PCBs made and want to ask around who would like some.
Please post in this thread how many you like, if you plan to use them for hub or bottle type dynamo, how many LEDs you plan to connect, what country you want them shipped to.
I estimate one of the PCBs will cost no more than EUR 5 (w/o components and assembly) plus a bit for shipping, but not sure abt the exact cost right now.
Update: Cost of my current stock is EUR 3.80 per PCB, plus shipping by letter. If you like one of these PCBs, please PM me.
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