Hi
Guys
Heres
another one to try Andy . Leave in the transistor that
drives the leds,
remove other(s) Now connect a resistor is series with the (2.2k-
4k7)
base,this is now your ir tx input (simulate with your basic stamp
kit ie
pulsing). Remove
the ground from the emitter and connect the emitter to
the
collector of a
second transistor.Connect the emitter of the second
tranny to
gnd .The base of the second tranny
is connected to +ve when
required
via a resistor .This transistor is your gate (zone
enable). If this
works and
you wish to use it in Homevision the second
transistor is not reqiured
as
Port A Pins perform exactly the same function
as the 2nd
tranny
Frank Mc.
----- Original Message -----
From: "Ian B"
<
Ian@xxxxxxx>
To: <
ukha_d@xxxxxxx>
Sent:
Monday, June 03, 2002 12:35 AM
Subject: RE: [ukha_d] Re: ir transmitter
some
success
> Not exactly bad. I think the later designs running
off
PortC are better as
> it does not involve negative logic i.e. '0' is
off
and 1 is on. At this
> stage when most of this stuff is on breadboard
I
would go to PortC. The
> relay ports are of more use for other things
to
some as well given their
> better spec for current switching. For
this
circuit we are using milliamps
> so it is of no
concern.
>
> I
have just looked at the manual (for the first time and as I had
to
unbury
> it) and it looks as though HV switches the +ve 5v. Can
someone confirm
this.
> If so the circuit(s) will need revising as
they
are designed to switch the
> ground. It is not a big issue but we
must
look at it now not later. I will
> post alternative circuits on my
site
ASAP.
>
> Ian
>