COB PCB with blinking led

[Roy Conrad]

I'm looking for a COB(chip on board) PCB with a blinking led. This can
be found in toys and electronic candles.
I need to find manufacturers or resellers which I think are mainly in
China.
If the cob+led isn't available, I'll also be interested just in the
cob.
I've already seen some kits from kitsrus and some cob from Comedia but
they don't do what I need: 10Hz, 1/4 duty-cycle.

I'd appreciate any help you could give me, even if there are other
newsgroups that I could ask for.


Thanks in advance!

 

[Mark VB]

"Roy Conrad" <roy.c@bigfoot.com> wrote in message
news:e22b6c12.0409220336.56fe15f@posting.google.com...

I'm looking for a COB(chip on board) PCB with a blinking led. This can
be found in toys and electronic candles.
I need to find manufacturers or resellers which I think are mainly in
China.
If the cob+led isn't available, I'll also be interested just in the
cob.
I've already seen some kits from kitsrus and some cob from Comedia but
they don't do what I need: 10Hz, 1/4 duty-cycle.

I'd appreciate any help you could give me, even if there are other
newsgroups that I could ask for.


Thanks in advance!

Hi,

The simplest way to make a led blinking is to use a simple NAND- or
NOR-gate, where the output is coupled back to the input via an RC-network.

I use a 74HC132 (Quad 2-input NAND Schmitt Trigger) to "scan" 7-seg
displays. When you use a 74HCT132 instead, you will get a duty-cycle around
28%. I do mention that variations in power-supply and temperature will
result in other output-characteristics.

If higher precision is needed, you can use an NE555 or LM555 (Timer IC) with
an adjustable duty-cycle and temperature stability better than 0.005% per
°C.


Mark Van Borm

 

[Roy Conrad]

"Mark VB" <mark.vanborm@telenet.be> wrote in message news:<IGf4d.254102$4N6.13070449@phobos.telenet-ops.be>...

"Roy Conrad" <roy.c@bigfoot.com> wrote in message
news:e22b6c12.0409220336.56fe15f@posting.google.com...
I'm looking for a COB(chip on board) PCB with a blinking led. This can
be found in toys and electronic candles.
I need to find manufacturers or resellers which I think are mainly in
China.
If the cob+led isn't available, I'll also be interested just in the
cob.
I've already seen some kits from kitsrus and some cob from Comedia but
they don't do what I need: 10Hz, 1/4 duty-cycle.

I'd appreciate any help you could give me, even if there are other
newsgroups that I could ask for.


Thanks in advance!

Hi,

The simplest way to make a led blinking is to use a simple NAND- or
NOR-gate, where the output is coupled back to the input via an RC-network.

I use a 74HC132 (Quad 2-input NAND Schmitt Trigger) to "scan" 7-seg
displays. When you use a 74HCT132 instead, you will get a duty-cycle around
28%. I do mention that variations in power-supply and temperature will
result in other output-characteristics.

If higher precision is needed, you can use an NE555 or LM555 (Timer IC) with
an adjustable duty-cycle and temperature stability better than 0.005% per
°C.


Mark Van Borm

Thanks for your reply.
I've already tried that option, but since I'm needing lots of them,
that would be expensive to make the PCB, buy the components and
assembly them.
What I'm really looking for is a COB like comedia have. I've tried it
but they don't have continuous operation and with 10Hz.
The COB is ready to run and if it has the led, it'd be better.

Roy Conrad

 

[R.Lewis]

"Roy Conrad" <roy.c@bigfoot.com> wrote in message
news:e22b6c12.0409230106.31f6fb79@posting.google.com...

"Mark VB" <mark.vanborm@telenet.be> wrote in message
news:<IGf4d.254102$4N6.13070449@phobos.telenet-ops.be>...
"Roy Conrad" <roy.c@bigfoot.com> wrote in message
news:e22b6c12.0409220336.56fe15f@posting.google.com...
I'm looking for a COB(chip on board) PCB with a blinking led. This can
be found in toys and electronic candles.
I need to find manufacturers or resellers which I think are mainly in
China.
If the cob+led isn't available, I'll also be interested just in the
cob.
I've already seen some kits from kitsrus and some cob from Comedia but
they don't do what I need: 10Hz, 1/4 duty-cycle.

I'd appreciate any help you could give me, even if there are other
newsgroups that I could ask for.


Thanks in advance!

Hi,

The simplest way to make a led blinking is to use a simple NAND- or
NOR-gate, where the output is coupled back to the input via an
RC-network.

I use a 74HC132 (Quad 2-input NAND Schmitt Trigger) to "scan" 7-seg
displays. When you use a 74HCT132 instead, you will get a duty-cycle
around
28%. I do mention that variations in power-supply and temperature will
result in other output-characteristics.

If higher precision is needed, you can use an NE555 or LM555 (Timer IC)
with
an adjustable duty-cycle and temperature stability better than 0.005%
per
°C.


Mark Van Borm

Thanks for your reply.
I've already tried that option, but since I'm needing lots of them,
that would be expensive to make the PCB, buy the components and
assembly them.
What I'm really looking for is a COB like comedia have. I've tried it
but they don't have continuous operation and with 10Hz.
The COB is ready to run and if it has the led, it'd be better.

Roy Conrad

I have missed the first part of the thread but if all yo want is to 'blink'
a led why do you need to be so complicated?
A surface mount discrete flasher uses very few components and is thus small
and cheap - see how the people that manufacture such things do it.