Timer Electronics Question

[mongo blongo]

Ive got me an electronic countdown timer.
(by the way i am shit with electronics!)
I have removed the speaker. When the time is up it would send 1.5v A.C to the speaker (i measured it with a multimeter). Now what i want to do is replace the speaker with some kind of electric activated switch to close a second circuit (to carry at least 9v D.C). I thought a relay switch would be good but i just can't find one which will operate at such a small voltage. http://theforum.virtualave.net/ubb/smilies/frown.gif
I was thinking maybe a transistor could do the job, but i don't know much about this or even what type of transistor to get!
I know this has been discussed before but none of the posts were that helpful!
Also before you say it the first thing i tried was to put a battery in series with the timer circuit but the power from the battery seems to close the switch in the timer!(making the timer useless)
Does anyone have any suggestions?

[EventHorizon]

There are many relays that would work and would mostlikly be the best [method]. Are you certain that the output was AC and not DC with a 1.5V ripple, with cheap equipment this could be possible.

Other circuits would work, but if you don't know how to get these to work, I'd really not use your device for setting something off. Sound like way to much margin of error.

[This message has been edited by EventHorizon (edited September 09, 2001).]

[mongo blongo]

What realys are yo refering to?
It was A.C im sure!

[Tony Montana]

You are going to want a PNP transistor to start with, these are off in the normal postion. Here is a place that sells them:
http://www.allelectronics.com/cgi-bin/category.cgi?category=550&type=store
Next you are going to have to make sure the voltages are right. What are you using for a det? Is it a lightbulb, this is a good choice as you can test if it works properly, and when ready to use. Using a nailfile, file a small hole in the bulb and fill it with powdered match heads(this will ignite any AP, HMTD).
http://members.optusnet.com.au/~hand/montana/trans.gif

[This message has been edited by Tony Montana (edited September 09, 2001).]

[mongo blongo]

Thanx Tony!
Im using a rocket ignitor (never fails) in Lead Azide with Picric Acid booster. Using a 9v Duracell (only battery that produces enough current for this kind of job)
I think i may actually have some of these! http://theforum.virtualave.net/ubb/smilies/smile.gif
Which one would use for these specs?
Or what would be printed on the transistor so that i may identify them?
Thanx dude!

[Tony Montana]

Mongo, I may be wrong, but plodding along like this is natural learning (at least in my case) and extracting transistors from amplifiers and tape decks proves to be an invaluble learning experience, I suggest the lightbulb method once again. As for Emitter Base and Current determination, that comes with experience with electronics and having your "SEMI-CONDUCTOR" up the right way! I also suggest a "bread board" for electrical experiments. But apart from that, all I can say is your prodding" is in the right direction, keep going!!!!

[mongo blongo]

Well I will just have to carry on experimenting then. http://theforum.virtualave.net/ubb/smilies/smile.gif
Do you suggest the Lightbulb simply so that you can test if it works? (you can just test if electricity flows with a buzzer or something?)
Is a "bread board" the thing which is like a grid with loads of holes in it? I think i may have seen one.
Thanx Dude! http://theforum.virtualave.net/ubb/smilies/smile.gif