Hybrid lighting - any electronics people out there?
novembercp
Posts: 58
Some time ago I bought a nifty device which switched dymano lights onto battery power whenever the dymano was stopped. I have no idea what this was called, it was just a black box just big enough to hold 2 AA's and a tiny circuit board. It was nicked along with my beloved Muddy Fox Courier in the early 90's.
Anyone out there know how to build one of these? I have some experience of building electronic circuits, should be simple enough, presumably a transistor which switches on the battery circuit when the dynamo current drops below x amps.
Anyone out there know how to build one of these? I have some experience of building electronic circuits, should be simple enough, presumably a transistor which switches on the battery circuit when the dynamo current drops below x amps.
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You can probably find more info than you ever needed/wanted to know on the bicycle light part of candlepowerforums.com - there has been a lot of stuff there recently about LED/dynamo circuits. If you cant find anything there already thats any use, there will definitely be people who can answer your question.0
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Well, novembercp, what you want is a schmitt trigger that drives an MOS transistor to do the power switching. Look for 74ALS14; also, you will need 5V sabiliser (the 100mA 7805L will be enough) to get the power for the trigger. I hope this helps a little
As a final warning, you will spend far more money than if just bought a new set of lights, but in this case I totally understand! It will be a cycling project, there's nothing more worthy blowing £100 and several weekends on!Computer geek, Manchester Wheelers' member since 20060 -
janm399 wrote:Well, novembercp, what you want is a schmitt trigger that drives an MOS transistor to do the power switching. Look for 74ALS14; also, you will need 5V sabiliser (the 100mA 7805L will be enough) to get the power for the trigger. I hope this helps a little
As a final warning, you will spend far more money than if just bought a new set of lights, but in this case I totally understand! It will be a cycling project, there's nothing more worthy blowing £100 and several weekends on!
As you say, it'd be a project but will cost me time and money! My last such project was to build a portable guitar amplifier. Definitely spent way more than the price of a ready - made one (which may have been better!), but had a lot of fun and learned a lot in the process.
Might be easier to search the city of Dublin (where I no longer live!) and find the original still attached to the stolen bike. Think I'll just buy new lights!0
