I know there are many elegant solutions around but I wanted a minimalist way of a) stopping my old bottle dynamo driven lights blowing bulbs on fast descents and b) to increase the brightness of the rear lights
For £1.98 I bought 10 IN4001 diodes and 10 5.7V/1W Zener diodes. I added some old 200 Ohm resistors and two red LEDs from some defunct battery rear lights at no cost.
The Zeners made a back to back 6V clipping circuit and the LED/resistor/diode (half wave rectified) replaced the rear light bulb.
I now have a brighter rear light and a bright but safe front light all in the original vintage housings. Total cost of new components 30p per bike.
And, most important, it was fun to do
Very cheap dynamo light upgrade
Re: Very cheap dynamo light upgrade
nice work! Next step is a DIY LED upgrade for the front light, obviously....
cheers
cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
Re: Very cheap dynamo light upgrade
Nice,
Lots more ideas here - http://pilom.com/BicycleElectronics/DynamoCircuits.htm
and a good source of leds is from GU10 bulbs where the electronics fail but the actual leds are fine.
viewtopic.php?f=5&t=116628
you may even be able to use a MR16 led bulb if there is room to squeeze one in.
Lots more ideas here - http://pilom.com/BicycleElectronics/DynamoCircuits.htm
and a good source of leds is from GU10 bulbs where the electronics fail but the actual leds are fine.
viewtopic.php?f=5&t=116628
you may even be able to use a MR16 led bulb if there is room to squeeze one in.
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840
Re: Very cheap dynamo light upgrade
Why not use a full wave rectifier for less flicker?
NB I would use an 'approved'* dynamo LED rear lamp in parallel for legal piece of mind (eg an electrically frugal one: spanninga's usually only use 30mA).
*Stvzo (with RKF3 if possible) or BS6102/3(rare )
NB I would use an 'approved'* dynamo LED rear lamp in parallel for legal piece of mind (eg an electrically frugal one: spanninga's usually only use 30mA).
*Stvzo (with RKF3 if possible) or BS6102/3(rare )
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Re: Very cheap dynamo light upgrade
I wondered about the flicker level but decided that as it only appeared at very low speed that a) it didn't matter much and b) might be considered a bonus - as I slow and the LED dims the flickering might make it more noticeable
Like the idea of using old GU10's too. I've pulled a few apart to show people that when they die it's not the LED just the cheap over-driven bias circuit, now I have a use for debris
Like the idea of using old GU10's too. I've pulled a few apart to show people that when they die it's not the LED just the cheap over-driven bias circuit, now I have a use for debris