"Uncle Peter" wrote in message
news
On Mon, 05 May 2014 20:12:23 +0100, Ian Field
wrote:



"Uncle Peter" wrote in message
news
On Mon, 05 May 2014 18:15:33 +0100, Ian Field
wrote:



"Uncle Peter" wrote in message
news On Mon, 05 May 2014 17:22:19 +0100, Ian Field
wrote:



"Daniel" wrote in message
...


URA dumbass!

Red LEDs weigh in at about 1 3/4V, green at just over 2V and white at
about
3.4V.

Most garden lights have a 2 transistor oscillator driving a flyback
inductor
to generate a higher voltage than the 1.2V battery - increasingly now
you
find a custom chip that integrates the daylight shut off function
when
sunlight activates the solar cell.

The latter sounds like mine, as apart from the chip blob (why are they
blobs? is that some kind of dust and water shield?) the only other
components are a capacitor and a resistor (and of course the battery,
LED,
and solar cell).

Some chips are available as the bare die which is glued to the PCB and
the
wire-bonds are made direct to the PCB tracks. They just drop a blob of
poxy
glue on it instead of it having regular encapsulation.

What's the advantages of that?

The 'resistor' is more likely a molded RF choke - it takes a bit of
practice
to tell them apart.

I seem to remember it has the usual coloured stripes and the same tube
shape with two bulges at each end.

The advantage of "black blob" chips is no type number so you can't tell
what
it is.

How is that an advantage?

Competitors have to design their own from scratch instead of buying stocks
of the same chip and copying the design.