First steps..

[Jim]

Hi Folks,

After spending ages dreaming about it, I've eventually taken my first
steps into the world of electronics by building this circuit

http://www.albinobrainchiggers.com/2005/10/my-jack-o-led.html

I've been out to buy all the bits, and figured out the schematic and
built it, and guess what? It works like a treat! yippee.. I can't wait
for my next project...

I'm learning as I go, and i appreciate that copying other peoples work
is perhaps not the best way forward, but there is one question that it
bugging me...

The circuit I've built is essentially three separate and independent 555
timer circuits linked only by the power rails. I'm powering it using a
(pretty weak) 9v battery. I would expect that when all the LED's are
lit together they would be slightly dimmer because of the drain on the
battery, but the opposite is true. When an LED comes on, any LEDs that
are already on get a bit brighter.. It's mad, I don't understand why.
any ideas?

thanks,

Jim

 

[Dan Hollands]

If in fact the only link is the power rails that must be where the
interaction is ocurring.

To prove it run the power and ground for each circuit directly back to the
power source so the athe the current for only one circuit goes thru any
power wire.

Dan

--
Dan Hollands
1120 S Creek Dr
Webster NY 14580
585-872-2606
[email protected]
www.QuickScoreRace.com

 

[John Popelish]

Hi Folks,

After spending ages dreaming about it, I've eventually taken my first
steps into the world of electronics by building this circuit

http://www.albinobrainchiggers.com/2005/10/my-jack-o-led.html

I've been out to buy all the bits, and figured out the schematic and
built it, and guess what? It works like a treat! yippee.. I can't wait
for my next project...

I'm learning as I go, and i appreciate that copying other peoples work
is perhaps not the best way forward, but there is one question that it
bugging me...

The circuit I've built is essentially three separate and independent 555
timer circuits linked only by the power rails. I'm powering it using a
(pretty weak) 9v battery. I would expect that when all the LED's are
lit together they would be slightly dimmer because of the drain on the
battery, but the opposite is true. When an LED comes on, any LEDs that
are already on get a bit brighter.. It's mad, I don't understand why.
any ideas?

The schematic shows no power connections for the 555. Did you connect
pins 1 and 8 to anything?
http://cache.national.com/ds/LM/LM555.pdf

 

[JeffM]

http://www.albinobrainchiggers.com/2005/10/my-jack-o-led.html

I would expect that when all the LED's are lit together
they would be slightly dimmer because of the drain on the battery,
but the opposite is true.
Jim

Not addressing the question you asked, but regarding LEDs in parallel:
http://groups.google.com/group/sci....not-be-paralleled+qqq+yyy+*-R-LED-Rtn-circuit