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Solar garden lights - 1.2V --> LED?

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Uncle Peter
Guest

Thu Apr 17, 2014 8:32 pm   



I just got some solar garden lights, and they seem to power an LED (colour changing) from a single 1.2V NiMH. Can you get LEDs with a forward voltage that low, or does it have a booster in it? All I can see is a microchip (one of those black blobs so I don't know what's in it), a capacitor, and a resistor.

--
Sky have just won the rights to screen the first World Origami Championships from Tokyo.
Unfortunately it's only available on Paper View.

Daniel
Guest

Fri Apr 18, 2014 5:50 pm   



On 18/04/14 00:32, Uncle Peter wrote:
Quote:
I just got some solar garden lights, and they seem to power an LED
(colour changing) from a single 1.2V NiMH. Can you get LEDs with a
forward voltage that low, or does it have a booster in it? All I can
see is a microchip (one of those black blobs so I don't know what's in
it), a capacitor, and a resistor.

LED's are Light Emitting Diodes, so can work from about 0.6V .... or
even lower maybe!

Daniel

Uncle Peter
Guest

Fri Apr 18, 2014 6:47 pm   



On Fri, 18 Apr 2014 12:50:36 +0100, Daniel <dxmm_at_albury.nospam.net.au> wrote:

Quote:
On 18/04/14 00:32, Uncle Peter wrote:
I just got some solar garden lights, and they seem to power an LED
(colour changing) from a single 1.2V NiMH. Can you get LEDs with a
forward voltage that low, or does it have a booster in it? All I can
see is a microchip (one of those black blobs so I don't know what's in
it), a capacitor, and a resistor.

LED's are Light Emitting Diodes, so can work from about 0.6V .... or
even lower maybe!


I should have tested it before asking. The LED gets 2.4V. The battery is 1.2V, there must be a voltage doubler in the chip.

Also what surprised me is the tri-colour LED (which gradually changes through all the colours of the rainbow) has only two legs - the colour changing is controlled by a chip inside the 5mm LED - the input to the LED is a constant 2.4V.

--
A man goes into a library and asks for a book on suicide.
The librarian says, "Fuck off, you won't bring it back!"

Ian Field
Guest

Mon May 05, 2014 10:22 pm   



"Daniel" <dxmm_at_albury.nospam.net.au> wrote in message
news:ik84v.62219$%x6.35160_at_fx16.iad...
Quote:
On 18/04/14 00:32, Uncle Peter wrote:
I just got some solar garden lights, and they seem to power an LED
(colour changing) from a single 1.2V NiMH. Can you get LEDs with a
forward voltage that low, or does it have a booster in it? All I can
see is a microchip (one of those black blobs so I don't know what's in
it), a capacitor, and a resistor.

LED's are Light Emitting Diodes, so can work from about 0.6V .... or even
lower maybe!


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.

Uncle Peter
Guest

Mon May 05, 2014 11:02 pm   



On Mon, 05 May 2014 17:22:19 +0100, Ian Field <gangprobing.alien_at_ntlworld.com> wrote:

Quote:


"Daniel" <dxmm_at_albury.nospam.net.au> wrote in message
news:ik84v.62219$%x6.35160_at_fx16.iad...
On 18/04/14 00:32, Uncle Peter wrote:
I just got some solar garden lights, and they seem to power an LED
(colour changing) from a single 1.2V NiMH. Can you get LEDs with a
forward voltage that low, or does it have a booster in it? All I can
see is a microchip (one of those black blobs so I don't know what's in
it), a capacitor, and a resistor.

LED's are Light Emitting Diodes, so can work from about 0.6V .... or even
lower maybe!

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).

--
110 people once tied for second prize in the Powerball Lottery after playing the same lucky numbers from a fortune cookie.

Ian Field
Guest

Mon May 05, 2014 11:15 pm   



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfecapydswtmtb_at_red.lan...
Quote:
On Mon, 05 May 2014 17:22:19 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Daniel" <dxmm_at_albury.nospam.net.au> wrote in message
news:ik84v.62219$%x6.35160_at_fx16.iad...
On 18/04/14 00:32, Uncle Peter wrote:
I just got some solar garden lights, and they seem to power an LED
(colour changing) from a single 1.2V NiMH. Can you get LEDs with a
forward voltage that low, or does it have a booster in it? All I can
see is a microchip (one of those black blobs so I don't know what's in
it), a capacitor, and a resistor.

LED's are Light Emitting Diodes, so can work from about 0.6V .... or
even
lower maybe!

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.

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

Uncle Peter
Guest

Tue May 06, 2014 12:18 am   



On Mon, 05 May 2014 18:15:33 +0100, Ian Field <gangprobing.alien_at_ntlworld.com> wrote:

Quote:


"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfecapydswtmtb_at_red.lan...
On Mon, 05 May 2014 17:22:19 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Daniel" <dxmm_at_albury.nospam.net.au> wrote in message
news:ik84v.62219$%x6.35160_at_fx16.iad...
On 18/04/14 00:32, Uncle Peter wrote:
I just got some solar garden lights, and they seem to power an LED
(colour changing) from a single 1.2V NiMH. Can you get LEDs with a
forward voltage that low, or does it have a booster in it? All I can
see is a microchip (one of those black blobs so I don't know what's in
it), a capacitor, and a resistor.

LED's are Light Emitting Diodes, so can work from about 0.6V .... or
even
lower maybe!

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?

Quote:
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.

--
Loose or missing nuts. Spank the monkey (Y/N)?

Ian Field
Guest

Tue May 06, 2014 1:12 am   



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfefs2ydswtmtb_at_red.lan...
Quote:
On Mon, 05 May 2014 18:15:33 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfecapydswtmtb_at_red.lan...
On Mon, 05 May 2014 17:22:19 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Daniel" <dxmm_at_albury.nospam.net.au> wrote in message
news:ik84v.62219$%x6.35160_at_fx16.iad...
On 18/04/14 00:32, Uncle Peter wrote:
I just got some solar garden lights, and they seem to power an LED
(colour changing) from a single 1.2V NiMH. Can you get LEDs with a
forward voltage that low, or does it have a booster in it? All I can
see is a microchip (one of those black blobs so I don't know what's
in
it), a capacitor, and a resistor.

LED's are Light Emitting Diodes, so can work from about 0.6V .... or
even
lower maybe!

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.

All the molded chokes have colour bands, they're usually slightly more
bulged than resistors - if you just can't tell, measure the resistance. It
should be very significantly less than the code would indicate a resistor to
be.

Uncle Peter
Guest

Tue May 06, 2014 1:50 am   



On Mon, 05 May 2014 20:12:23 +0100, Ian Field <gangprobing.alien_at_ntlworld.com> wrote:

Quote:


"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfefs2ydswtmtb_at_red.lan...
On Mon, 05 May 2014 18:15:33 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfecapydswtmtb_at_red.lan...
On Mon, 05 May 2014 17:22:19 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Daniel" <dxmm_at_albury.nospam.net.au> wrote in message
news:ik84v.62219$%x6.35160_at_fx16.iad...


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?

Quote:
All the molded chokes have colour bands, they're usually slightly more
bulged than resistors - if you just can't tell, measure the resistance. It
should be very significantly less than the code would indicate a resistor to
be.


I see. I can't be bothered dismantling one again to find out.
Are the chokes the ones with the squarer bulges?

--
It is OK to let your mind go blank, but please turn off the sound.

Ian Field
Guest

Tue May 06, 2014 2:31 am   



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfej2gtxswtmtb_at_red.lan...
Quote:
On Mon, 05 May 2014 20:12:23 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfefs2ydswtmtb_at_red.lan...
On Mon, 05 May 2014 18:15:33 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfecapydswtmtb_at_red.lan...
On Mon, 05 May 2014 17:22:19 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Daniel" <dxmm_at_albury.nospam.net.au> wrote in message
news:ik84v.62219$%x6.35160_at_fx16.iad...


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.

Uncle Peter
Guest

Tue May 06, 2014 3:10 am   



On Mon, 05 May 2014 21:31:42 +0100, Ian Field <gangprobing.alien_at_ntlworld.com> wrote:

Quote:


"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfej2gtxswtmtb_at_red.lan...
On Mon, 05 May 2014 20:12:23 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfefs2ydswtmtb_at_red.lan...
On Mon, 05 May 2014 18:15:33 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfecapydswtmtb_at_red.lan...




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.


Overall in the interest of advancing technology, this is a bad thing.

--
Rule 34: If it exists, there's porn of it.

Ian Field
Guest

Tue May 06, 2014 9:50 pm   



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfensawtswtmtb_at_red.lan...
Quote:
On Mon, 05 May 2014 21:31:42 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfej2gtxswtmtb_at_red.lan...
On Mon, 05 May 2014 20:12:23 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfefs2ydswtmtb_at_red.lan...
On Mon, 05 May 2014 18:15:33 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfecapydswtmtb_at_red.lan...




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.

Overall in the interest of advancing technology, this is a bad thing.


The black blob chips seem to have increased since RoHS banned lead in
solder - the wire bonds have to be there in one form or another, whether
they go straight to PCB tracks or to pins that have to be soldered - solder
joints were a reliability issue before RoHS - now solder joints that look OK
can be defective and/or not last long, and solder without lead tends to
sprout metallic whiskers that can short adjacent pins.

The Americans know RoHS is weapons grade bolonium - but they have to comply
if they want to export to the EU.

Uncle Peter
Guest

Tue May 06, 2014 11:13 pm   



On Tue, 06 May 2014 16:50:07 +0100, Ian Field <gangprobing.alien_at_ntlworld.com> wrote:

Quote:


"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfensawtswtmtb_at_red.lan...
On Mon, 05 May 2014 21:31:42 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfej2gtxswtmtb_at_red.lan...
On Mon, 05 May 2014 20:12:23 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfefs2ydswtmtb_at_red.lan...






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.

Overall in the interest of advancing technology, this is a bad thing.

The black blob chips seem to have increased since RoHS banned lead in
solder - the wire bonds have to be there in one form or another, whether
they go straight to PCB tracks or to pins that have to be soldered - solder
joints were a reliability issue before RoHS - now solder joints that look OK
can be defective and/or not last long, and solder without lead tends to
sprout metallic whiskers that can short adjacent pins.


So the blob keeps them in check?

Quote:
The Americans know RoHS is weapons grade bolonium - but they have to comply
if they want to export to the EU.


In a lot of respects the Americans have MORE safety. They have curfews for teenagers, they aren't allowed to fuck till they're 18, and you can't buy a TENS unit without a prescription.

--
We've all heard that a million monkeys banging on a million typewriters will eventually reproduce the works of Shakespeare.
Now, thanks to the Internet, we know this is not true.

Ian Field
Guest

Tue May 06, 2014 11:58 pm   



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xff7gjalswtmtb_at_red.lan...
Quote:
On Tue, 06 May 2014 16:50:07 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfensawtswtmtb_at_red.lan...
On Mon, 05 May 2014 21:31:42 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfej2gtxswtmtb_at_red.lan...
On Mon, 05 May 2014 20:12:23 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfefs2ydswtmtb_at_red.lan...






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.

Overall in the interest of advancing technology, this is a bad thing.

The black blob chips seem to have increased since RoHS banned lead in
solder - the wire bonds have to be there in one form or another, whether
they go straight to PCB tracks or to pins that have to be soldered -
solder
joints were a reliability issue before RoHS - now solder joints that look
OK
can be defective and/or not last long, and solder without lead tends to
sprout metallic whiskers that can short adjacent pins.

So the blob keeps them in check?

The Americans know RoHS is weapons grade bolonium - but they have to
comply
if they want to export to the EU.

In a lot of respects the Americans have MORE safety. They have curfews
for teenagers, they aren't allowed to fuck till they're 18, and you can't
buy a TENS unit without a prescription.


It would be difficult to prevent people building their own TENS - meanwhile
over here, possession of a stun gun can get you locked up for a firearms
offence whether you bought it or built it.

Uncle Peter
Guest

Wed May 07, 2014 12:57 am   



On Tue, 06 May 2014 18:58:21 +0100, Ian Field <gangprobing.alien_at_ntlworld.com> wrote:

Quote:


"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xff7gjalswtmtb_at_red.lan...
On Tue, 06 May 2014 16:50:07 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfensawtswtmtb_at_red.lan...
On Mon, 05 May 2014 21:31:42 +0100, Ian Field
gangprobing.alien_at_ntlworld.com> wrote:



"Uncle Peter" <no_at_spam.com> wrote in message
news:op.xfej2gtxswtmtb_at_red.lan...








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

Overall in the interest of advancing technology, this is a bad thing.

The black blob chips seem to have increased since RoHS banned lead in
solder - the wire bonds have to be there in one form or another, whether
they go straight to PCB tracks or to pins that have to be soldered -
solder
joints were a reliability issue before RoHS - now solder joints that look
OK
can be defective and/or not last long, and solder without lead tends to
sprout metallic whiskers that can short adjacent pins.

So the blob keeps them in check?

The Americans know RoHS is weapons grade bolonium - but they have to
comply
if they want to export to the EU.

In a lot of respects the Americans have MORE safety. They have curfews
for teenagers, they aren't allowed to fuck till they're 18, and you can't
buy a TENS unit without a prescription.

It would be difficult to prevent people building their own TENS


To make a proper high frequency one, you need to know about electronics. There have been many cases of people using mains directly to the nipples though!

Quote:
- meanwhile
over here, possession of a stun gun can get you locked up for a firearms
offence whether you bought it or built it.


Er what? They're not illegal are they? I thought you could buy them in shops? I'm referring to the little ones with the two stumpy pins, not the ones that fire a short distance.

--
COWS, CALVES: NEVER BRED. Also 1 gay bull for sale.

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