JR611 SOIC-8 in bicycle lamp.

Its a long shot, as its probably a house coded part.

Its a Crivit Sport LED bicycle lamp from the Lidl discount store.

Originally it was the LED that went intermittent, but when a second unit died I decided I could spare one to experiment on.

Suitable LED parts are on order from Ebay, but I thought I'd have a go at upgrading it with a switch mode current control. The circuit is ready, but I need to identify the "glue logic" type stuff on the PCB.

The on/off button is a simple pushbutton, the latching is done electronically. It also has a low battery warning LED - these features would be nice to retain, but I need a little help identifying the stuff on the board.

Thanks.

Reply to
Ian Field
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Have you isolated and powered each power LED from a bench ps?

Reply to
N_Cook

Replacing the LED chip fixed the intermittent fault, so that pretty much eliminates the circuit on the PCB.

But While I'm working on it - I'd like to upgrade it with SMPSU technology.

Reply to
Ian Field

Adding some extra heatsinking would not go amiss

Reply to
N_Cook

The whole point is to reduce dissipation - not disguise it.

The LED rating is no less than 1W and the bicycle lamp specification only claims 0.6W - the LED barely gets warm.

Reply to
Ian Field

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I'd worry about the light distribution from a replacement LED; an eBay item usually doesn't have a good angular distribution specification...

There are some chips that do this; generally, though, it's going to be a small-outline surface mount part, and will only work from a limited voltage input range. This is a typical such part: which, as I read it, is suitable for three alkaline cells in series (4.5V nominal).

If you are going to have a switchmode supply, it's most efficient to boost voltage (the switches and diode have lower losses at lower current) and use multiple LEDs in series.

Reply to
whit3rd

It'd look pretty funny with multiple reflectors to fit over the multiple LEDs - and I'd have to scrap a lot of bicycle lights to get them.

The modified buck I'm using puts the LED in series with charging the inductor - and the catch diode gives it another bite of the cherry.

Reply to
Ian Field

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