12v Battery Monitor Problem

[BBQTime]

I have a problem with this circuit in the description it says the following

BATTERY MONITOR MkII

This battery monitor circuit uses 3 separate LEDs.
The red LED turns on from 6v to below 11v.
It turns off above 11v and
The orange LED illuminates between 11v and 13v.
It turns off above 13v and
The green LED illuminates above 13v

What is happening
6v red led on...... stays on
11v orange led on..... both orange and red on
12.5v green led on red and orange led turns off at the same time

When I remove the red led from the circuit both orange and green work as they should ? Checked and double checked zeners and resistors.....Cant figure why the red led is not turning off.


http://www.talkingelectronics.com/projects/200TrCcts/101-200TrCcts.html

Cheers Thanks

 

[gmphadte]

Try 2 red LEDs in series instead of one.

gmphadte

 

[BBQTime]

The red led is not turning off over 11v......Thanks for replying sorry but how would using 2 leds rectify the problem

 

[gmphadte]

The transistor that shunts the red LED does not turn on hard. Two LEDs will increase the voltage at the collector.

gmphadte

 

[BBQTime]

2 red leds light nothing changes the problem is the red led stays on after 11v '' The red LED turns on from 6v to below 11v.
It turns off above 11v ''

 

[chemelec]

TRY SOME OF THESE CIRCUITS:

http://chemelec.com/Projects/Battery-Monitor/Battery-Monitor.htm

 

[audioguru]

I think you have the collector and emitter pins of the BC547 mixed up and also maybe the BC557. These are European transistors and their pins are C, B and E while American transistors are E, B and C.

 

[BBQTime]

Sorted audioguru, I had the leads correct but the wrong transistor lol...... O dear a newbie error Cheers for the help.