Re: ir transmitter some success

["andy_powell_is" <ukha@xxxxxxx>]

Frank Ian, Ian, 

I've actually found a problem :(

When +5v is applied to the base of the first transistor, even if the 
collector is not connected, the 2nd transistor is supplying current 
to the LEDs... I don't understand that. didn't think it should 
happen :(

any ideas

Andy


--- In ukha_d@y..., "Frank Mc Alinden" <armagh@b...>
wrote:
> Hi Andy
>            
Isnt it  brill when things go right .Your doing great. 
Good idea
> about the Basic Stamp. I spent all day yesterday frustrated . You 
wouldnt
> learn much if everything went right ,its when it goes wrong thats 
when you
> learn. Did you post your photos on Marks Website ? if so how?
> Good Luck
> 
> Frank Mc
> ----- Original Message -----
> From: "andy_powell_is" <ukha@b...>
> To: <ukha_d@y...>
> Sent: Sunday, June 02, 2002 7:18 PM
> Subject: [ukha_d] Re: ir transmitter some success
> 
> 
> > Good stuff Frank... at the moment I am just using this to learn,
in
> > the end I'll probably end up using one of the designs from
you
> > experts...
> >
> > I've had a little brainwave here too... before connecting to
> > Homevision I'm actually going to sacrifice a basic stamp..
(well
> > sacfrifice is'tn the right word as it SHOULD be ok
afterwards)..
> >
> > The Basic stamp can cope with 30ma max per pin and 60ma per 8
pins..
> > which means if i create a fake homevision using the basic stamp I
can
> > certainly check on the current draw before the final
connection..
> >
> > Obviously this is the final test before connecting to
homevision..
> > before all that I need to take some measurements.... but I
have
> > transferred the first bit from  breadboard to stripboard...
:D :D
> >
> > and it works!! :D .. I'm just using this one really as 
layout...and
> > testing, I need to compress  it really...
> >
> > I also think I have got it down to about 512ma total of 8 X 9
leds, i
> > think by chance I managed to get some sensitive ir emitter leds
I
> > need to double check but I think I can get away with 600ohm 
(possibly
> > more as the emitters will be right beside the internal IR 
receiver of
> > any kit) resistors for them and the visible leds have 3.9k 
resistors
> > and are still fairly bright... (again all by chance)
> >
> > Part numbers for farnell are:
> >
> > 178301 Ir Emitter
> >
> > (farnell datasheet http://www.farnell.com/datasheets/5344.pdf
)
> >
> > 3013900 yellow led
> >
> > (no datasheet at farnell but it is at www.marl.co.uk  marl
part no
> > 352-582-20 )
> >
> > Andy
> >
> >
> > --- In ukha_d@y..., "Frank Mc Alinden"
<armagh@b...> wrote:
> > > Hi Andy , Ian + Ian
> >
>                            
Had some success today with the 8 
zone
> > ir controller . I decided to bypass the opto connected to 
incoming ir
> > signal from Hv to confirm my suspicions. Tried it again and it
worked
> > but only with two ir leds inserted in the Zone Splitter . Looked
at
> > my schematic and realised it was slightly different to my
homebrew
> > circuit. In my homebrew unit the driver transistors were
connected
> > common emitter but my new circuit was common collector .Re did
the
> > driver transistors and tried again. Now works with all 8 ir leds
in
> > Zone Splitter on all Zones . The range is approx 15ft and i 
monitored
> > the current which was approx  5mA . I set up my Hv ports
thru the
> > control menu rather than a macro at this stage just to confirm
my
> > hardware was connected ok. Would still like to use opto isolation
on
> > the incoming ir ,will order something from rs components. Now
must
> > update my drawing before i forget.
> > >
> > > Frank Mc
> >
> >
> >
> > For more information: http://www.automatedhome.co.uk
> > Post message: ukha_d@xxxxxxx
> > Subscribe:  ukha_d-subscribe@xxxxxxx
> > Unsubscribe:  ukha_d-unsubscribe@xxxxxxx
> > List owner:  ukha_d-owner@xxxxxxx
> >
> > Your use of Yahoo! Groups is subject to 
http://docs.yahoo.com/info/terms/
> >
> >



For more information: http://www.automatedhome.co.uk
Post message: ukha_d@xxxxxxx 
Subscribe:  ukha_d-subscribe@xxxxxxx 
Unsubscribe:  ukha_d-unsubscribe@xxxxxxx 
List owner:  ukha_d-owner@xxxxxxx

Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.