if I was to use a standard 6v wall plug what is the standard female adapter needed for that?

Depends on the wall plug. Most wall plugs use a 2.1mm I.D. and 5.5mm O.D. plug. If you've got a 6VDC wall plug handy, measure the I.D. and O.D. before buying anything.

Alternately, you can buy the jack and if doesn't fit your plug, replace the plug. Some possibilities are this and this. You can get these at bigger suppliers like Digikey for less I believe.

2nd question if the alarm isn't loud enough after testing how hard would it be to increase the volume?

If you want to hear it in a small- to medium-sized room without bothering people greatly, this, this, or this would work.

If you want to wake the dead or scare the bejeezes out of an intertruder, then look at this. I've used this one, but it requires 7VDC or more, so you'd have to add a 5V or so regulator to power the PIR sensor. I've got a design using a Zener diode and resistor if parts count is a problem.

You can buy similar buzzers from Digikey and the like, but if memory serves, RadioShack actually cost less in this case I think.

To answer your question, there is no real good way to adjust the volume of a buzzer, at least electronically. They don't function like speakers where more power means more volume. They're set at one volume, though changing the voltage can change the pitch or tone. You need to use a baffle (works similiar to an air vent in your house) or cover/enclose the buzzer with material until you get the volume you want. You may find simply placing the buzzer inside your project enclosure with no holes will be enough.

 

hmmm ok decisions decisions lol

 

ok so ive hit a small snag.

which of these pins is power and which is ground?

http://www.schurterinc.com/var/schu...s/document/datasheet/en/pdf/typ_4840.2211.pdf

 

It depends exclusively on the power supply you're using. Safest bet is to plug into your supply and use a meter to determine which pin is + and which is -.

 

oh really? there is no standard? interesting.

 

Most of the time (90% or more in my opinion), positive is on the center pin, but there are exceptions.

 

oh really? there is no standard? interesting.

Not as far as I can tell. Unlike tracecom's experience, I'd say it's more like 50:50. I would never assume one or the other. But they're almost always marked at the wall wart.