700 cd LED Bike Light - from OSRAM Spotlight

I have been tracking the development of LED replacement domestic light bulbs.  It seemed to me, a good domestic spot light would make a great cheap bike front light.

The perfect OSRAM spotlight just turned-up in my local DIY shop - so I have had a go. I am very pleased with the results. I recon I have made a bike light for around £20 that would retail for well over £200 from a bike shop.

Step 1: Buy The Bulb

I bought the OSRAM LED Superstar PAR16 35 25

This is a 240Vac 4.5 Watt replacement for 35 Watt GU10 halogen spotlights. It has a narrow 25 degree beam angle.


There may be better units to start with to be found if you scour the internet, for example 12V, or single LED rather than 3 LED array.  I liked this OSRAM one because it is near watertight, comes apart with screws, and looks the part.  (Unfortunately I didn't take any photos of the unmodifed spotlight - but you can imagine the GU10 terminals in the place of the switch and lead exit in the photo below, other wise it is unchanged externally. 

Comments

[iamvivekyadav]

I got the same light, and on the PCB there is a BP3102, which i found out is an LED driver, isn't it possible to make use of the same IC on the PCB by removing some parts off and plugging it on using 12v battery? like removing the transformer, rectifier diodes etc

[AlThorpe]

Hi, I'd be interested in trying this. If you can post up your diagrams before they get "filed". Al

[Almondsbury Puffer]

Hi there - here is a quick sketch of the circuit you will find on the diode plate. I modified this arrangement by removing the resistor and shorting the diode, as these just waste battery power in a DC arrangement.

I'll try and draw-up the DC constant current source circuit - but it is identical to the one on Dan's - High Power LED Driver Circuits article

[cqi]

nice idea!

[anip12]

oh nice think

[profpat]

nice one!