Re: Simple LED Alarm Bell for CCTV recorder

[Crash Gordon® <NONE@xxxxxxxx>]

You'll have to knock the voltage down for the LEDs too..otherwise they =
make a nice crackly-popping sound as the plastic shoots across the room.

I "think" from 12v to 3v is a 660 ohm resistor...to give you voltage =
drop...something like that.=20


<me@xxxxxxxxxxx> wrote in message =
news:lr9c31t6t1qgvqiijck5m2v8fmslnst55b@xxxxxxxxxx
> On Mon, 14 Mar 2005 17:35:52 -0500, "Jackcsg" <nospam@xxxxxxxxxx>
> wrote:
>=20
> >It was simple until you said you wanted the LED to flash. Are you =
good with
> >a solder gun? It is easily done, but it's going to be a little =
intricate if
> >you're only a DIY'er. Do you want the buzzer to be intermittent with =
the
> >LED, or a small steady buzz? The switches are easy because you can =
use a
> >DPDT switch to "shunt" the alarm device.
>=20
> I think a small steady buzz.=20
> Note that the CCTV DVR box has 8 wires all 500ma, 12volts each.=20
> All 8 wires from CCTV DVR would go into one black box that is drilled
> on the front, 8 LEDs, 8 switches (1 per sensor), and buzzer inside.
>=20
> There should be some way to handle the amp and voltage so it doesn't
> go back and blow up the CCTV box.
>=20
> I've forgotten everything they taught me in science classes. If I had
> a diagram I could show it to the people in Maplin.
>