Electronics: Modify Cree like Motorcycle LED Fog Projector Light

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U5, U3 U7 Cree LED light with 3000lm and 30W?

There are various cheap High Power LED motorcyle LED lights out there, all coming with different circuits but all with 3 Modes: High Beam, Low Beam and Strobe Light.

A friend baught some of these LED Lights and asked me to remove the Strobe and Low Beam. Unfortunately, non of the existing posts had the same circuit board inside. During my research and tests I blew one the pair. I hoped to get a known circuit driven Light by buying another pair with Devil Eye, a blue Angel LED circle which is specified with 12-80V.

This Motorcyle Light had again another circuit than all I could find in the internet. Bumpp. The printing on the box was also not helpful: “HJG Projectoe Light” (yes, with typo!). I assume HJG claims that this will work from 12-80V. I assume further it is some of the LED Lights claiming to do 3000lm with a 30W Cree like LED. Measuring the power consumption at 12-13V, it only consumes 0.650A. That is only about 7.8W at 12V!

OK, I managed to find the capacitor, that holds the ‘memory’ to make the circuit toggle between high, low and strobed beam, the answer is C5 (not 42). I just shorted all capacitors one after the other between switching the power on/off until the circuit does the high beam again after a power cycle. Do not cycle the power to fast, the circuit will still cycle thru the modes with this modification, if you switch the power to fast (for me under 2 seconds or so). I put a resistor of 10K on top of C5, one time a radial one with 1/8W, the other with a SMD resistor of 10K.


I do not describe here how to disassemble and re-assemble the housing. You need to apply some silicon below the Lens and arround the cables. Interestingly one circuit plate was mounted with a small amount of heat sink paste, the other not. I used paste in both on assembling. The housing is mounted in a cave with two screws where no silicon is applied. So the housing will never be very water resistent. I wonder how long these Lights will survive real use on a motorcyle.

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