Re: Re: Hmevision ir transmitter

["Ian Davidson" <ian@xxxxxxx>]

Hi

I've not been following this thread but I have just drawn out the
circuit
you described.

The BC182 will never conduct because it never has any voltage on it. i.e.
it
is either not connected or connect to ground via the switch. The bc182 is
an
NPN transistor and requires at least 0.7v between b/e junction to
conduct.
If you add a pull up resistor between the base and vcc it should work
but
you will need a value high enough to prevent exceeding the base current.
If
you tell me exactly what you want to achieve I'll try to be more
helpful.

Ian D

----- Original Message -----
From: "andy_powell_is" <ukha@xxxxxxx>
To: <ukha_d@xxxxxxx>
Sent: Thursday, May 30, 2002 7:59 PM
Subject: [ukha_d] Re: Hmevision ir transmitter


>
> Ian,
>
> I'm actually stubling at the first hurdle here...
>
> I have :
>
> One one breadboard with a 5v supply a BC182, C is connected to +5v
> via a resistor, B is connected to Ground (via a push switch) and E
is
> connected to the B of a 2N2222 on another breadboard with 5v
supply
> (spearate from the first one). The C of the 2N2222 is connected to
2
> LED's in series with a 220ohm resistor and the E is connected to
the
> ground of the supply on this board.
>
> I expected the LED's to light up - guess what? It does nothing :(
>
> Any ideas???
>
> I thought it was the circuit I'd drawn (uploaded to the files
area)
> before...
>
> Andy :(
>
>
>
>
>
> --- In ukha_d@y..., "Ian B" <Ian@M...> wrote:
> >
> > > I noticed that you said you were using 3 port pins, which
sounds
> > > better than using 8...
> >
> > Andy
> >
> > I think Frank has built this round a 3 to 8 decoder which
means
> only one
> > zone could be active at any on time. Using all 8 pins of port
A
> gives you
> > any combination you want simultaneously.
> >
> > Ian B
>
>
>
> 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.