Hi guys.
I've included a link to a small Circuit which im having trouble with.
I made it thinking that I was dealing with a switched possative feed, but it
turns out its actualy negative switched.
The Idea was to make the LED stay lit until the switched possative line goes
high.
Trouble is with it being High all the time the LED stays off. The LED
sometimes does not even come on when theits switched.
Because the voltage on the other end does not drop enough.

What would be needed to go between the cuircuits to get the original
affect.?
http://www.wombatppc.dsl.pipex.com/image/problem.jpg
Fig 1. is how its supposed to work
Fig 2. is the problem


Any help welcome.


--
Regards
Wombat

Find more info at:
http://www.wombatppc.dsl.pipex.com/

On Wed, 13 Jun 2007 07:43:59 +0100, "Wombat-Pipex-News"
wrote:

Hi guys.
I've included a link to a small Circuit which im having trouble with.
I made it thinking that I was dealing with a switched possative feed, but it
turns out its actualy negative switched.
The Idea was to make the LED stay lit until the switched possative line goes
high.
Trouble is with it being High all the time the LED stays off. The LED
sometimes does not even come on when theits switched.
Because the voltage on the other end does not drop enough.

What would be needed to go between the cuircuits to get the original
affect.?
http://www.wombatppc.dsl.pipex.com/image/problem.jpg
Fig 1. is how its supposed to work
Fig 2. is the problem


Any help welcome.

---
I'm somewhat confused by your description. Do you want the LED to
illuminate when the lamp is ON or when it's OFF?


--
JF

"John Fields" wrote in message
...
On Wed, 13 Jun 2007 07:43:59 +0100, "Wombat-Pipex-News"
wrote:

Hi guys.
I've included a link to a small Circuit which im having trouble with.
I made it thinking that I was dealing with a switched possative feed, but
it
turns out its actualy negative switched.
The Idea was to make the LED stay lit until the switched possative line
goes
high.
Trouble is with it being High all the time the LED stays off. The LED
sometimes does not even come on when theits switched.
Because the voltage on the other end does not drop enough.

What would be needed to go between the cuircuits to get the original
affect.?
http://www.wombatppc.dsl.pipex.com/image/problem.jpg
Fig 1. is how its supposed to work
Fig 2. is the problem


Any help welcome.

---
I'm somewhat confused by your description. Do you want the LED to
illuminate when the lamp is ON or when it's OFF?


--
JF

When it is off.
As the cars displays is made from LEDs its best to have them all lit at
once, then when something is Not lit is not working.
Just like if a bulb fails, its no longer lit !

On Wed, 13 Jun 2007 21:09:37 +0100, "Wombat-Pipex-News"
wrote:

"John Fields" wrote in message
.. .
On Wed, 13 Jun 2007 07:43:59 +0100, "Wombat-Pipex-News"
wrote:

Hi guys.
I've included a link to a small Circuit which im having trouble with.
I made it thinking that I was dealing with a switched possative feed, but
it
turns out its actualy negative switched.
The Idea was to make the LED stay lit until the switched possative line
goes
high.
Trouble is with it being High all the time the LED stays off. The LED
sometimes does not even come on when theits switched.
Because the voltage on the other end does not drop enough.

What would be needed to go between the cuircuits to get the original
affect.?
http://www.wombatppc.dsl.pipex.com/image/problem.jpg
Fig 1. is how its supposed to work
Fig 2. is the problem


Any help welcome.

---
I'm somewhat confused by your description. Do you want the LED to
illuminate when the lamp is ON or when it's OFF?


--
JF

When it is off.
As the cars displays is made from LEDs its best to have them all lit at
once, then when something is Not lit is not working.
Just like if a bulb fails, its no longer lit !

---
I still don't get it, but no matter. If you want the LED to turn on
when the lamp is off, try this: (View in Courier)

..V+---+------[REG]-----------+
.. | | |
.. [LAMP] GND [R]
.. | |
.. | |A
.. | [LED]
.. | |
.. | C
.. +---------[10k]------B 2N3904
.. | E
.. O-- | |
.. | |
.. O |
.. | |
..GND-------+-----------------+


If you want it to turn on when the lamp is on, try this:


..V+---+------[REG]---------+-----------+
.. | | | |
.. [LAMP] GND [100K] |
.. | | |
.. | | E
.. +---------[1N4001]--+--[10K]--B 2N3906
.. | C
.. O-- | |
.. | [R]
.. O |
.. | [LED]
.. | |K
..GND-------+---------------------------+


--
JF

"John Fields" wrote in message
...
On Wed, 13 Jun 2007 21:09:37 +0100, "Wombat-Pipex-News"
wrote:

"John Fields" wrote in message
. ..
On Wed, 13 Jun 2007 07:43:59 +0100, "Wombat-Pipex-News"
wrote:

Hi guys.
I've included a link to a small Circuit which im having trouble with.
I made it thinking that I was dealing with a switched possative feed,
but
it
turns out its actualy negative switched.
The Idea was to make the LED stay lit until the switched possative line
goes
high.
Trouble is with it being High all the time the LED stays off. The LED
sometimes does not even come on when theits switched.
Because the voltage on the other end does not drop enough.

What would be needed to go between the cuircuits to get the original
affect.?
http://www.wombatppc.dsl.pipex.com/image/problem.jpg
Fig 1. is how its supposed to work
Fig 2. is the problem


Any help welcome.

---
I'm somewhat confused by your description. Do you want the LED to
illuminate when the lamp is ON or when it's OFF?


--
JF

When it is off.
As the cars displays is made from LEDs its best to have them all lit at
once, then when something is Not lit is not working.
Just like if a bulb fails, its no longer lit !

---
I still don't get it, but no matter. If you want the LED to turn on
when the lamp is off, try this: (View in Courier)

.V+---+------[REG]-----------+
. | | |
. [LAMP] GND [R]
. | |
. | |A
. | [LED]
. | |
. | C
. +---------[10k]------B 2N3904
. | E
. O-- | |
. | |
. O |
. | |
.GND-------+-----------------+


If you want it to turn on when the lamp is on, try this:


.V+---+------[REG]---------+-----------+
. | | | |
. [LAMP] GND [100K] |
. | | |
. | | E
. +---------[1N4001]--+--[10K]--B 2N3906
. | C
. O-- | |
. | [R]
. O |
. | [LED]
. | |K
.GND-------+---------------------------+


--
JF

Hi John.
Thats not realy what I wanted to do.
I know I could make it all work fine from scratch, But I wanted somthing
that would plug in between my existing boards.
the ? in my diagram is where it would need to be.
I dont think the above diagram would do that.

Regards
Wombat.

On Thu, 14 Jun 2007 07:14:54 +0100, "Wombat-Pipex-News"
wrote:


Hi John.
Thats not realy what I wanted to do.
I know I could make it all work fine from scratch, But I wanted somthing
that would plug in between my existing boards.
the ? in my diagram is where it would need to be.
I dont think the above diagram would do that.


---
If you want the LED to come on when the lamp is off, this should do
it:

.. +------------------+
.. | NEW |
.. | |
.. | VREG |
.. | | |
.. | [R] |
.. +V | | |
.. | | +------|--[R]--+--[INVERTER]--[R]--+
.. [LAMP] | | | | |A
.. | | C | [R] [LED]
.. +-----|--[R]--B 2N3904 | | |
.. | | E | GND GND
.. [SWITCH] | | |
.. | | GND |
.. GND +------------------+



--
JF

"John Fields" wrote in message
...
On Thu, 14 Jun 2007 07:14:54 +0100, "Wombat-Pipex-News"
wrote:


Hi John.
Thats not realy what I wanted to do.
I know I could make it all work fine from scratch, But I wanted somthing
that would plug in between my existing boards.
the ? in my diagram is where it would need to be.
I dont think the above diagram would do that.


---
If you want the LED to come on when the lamp is off, this should do
it:

. +------------------+
. | NEW |
. | |
. | VREG |
. | | |
. | [R] |
. +V | | |
. | | +------|--[R]--+--[INVERTER]--[R]--+
. [LAMP] | | | | |A
. | | C | [R] [LED]
. +-----|--[R]--B 2N3904 | | |
. | | E | GND GND
. [SWITCH] | | |
. | | GND |
. GND +------------------+



--
JF

Thanks John
Ill give that a pop, and let you know if it works.
Did you get the files I sent you via e-mail.?

Regards
Wombat

On Thu, 14 Jun 2007 17:36:51 +0100, "Wombat-Pipex-News"
wrote:

"John Fields" wrote in message
.. .
On Thu, 14 Jun 2007 07:14:54 +0100, "Wombat-Pipex-News"
wrote:


Hi John.
Thats not realy what I wanted to do.
I know I could make it all work fine from scratch, But I wanted somthing
that would plug in between my existing boards.
the ? in my diagram is where it would need to be.
I dont think the above diagram would do that.


---
If you want the LED to come on when the lamp is off, this should do
it:

. +------------------+
. | NEW |
. | |
. | VREG |
. | | |
. | [R] |
. +V | | |
. | | +------|--[R]--+--[INVERTER]--[R]--+
. [LAMP] | | | | |A
. | | C | [R] [LED]
. +-----|--[R]--B 2N3904 | | |
. | | E | GND GND
. [SWITCH] | | |
. | | GND |
. GND +------------------+



--
JF

Thanks John
Ill give that a pop, and let you know if it works.
Did you get the files I sent you via e-mail.?

---
Yup!


--
JF