I want to have an alarm device that is tiny but loud, not sure where to start. I heard of a lm386 amp..though not familiar. All i need is a simple loud tone to be generated and the smaller the speaker the better. Any suggestions?
Simple piezo alarm sounder, readily available from the likes of Tandy / Radio-Shack etc. These come as a complete package, with inbuilt oscillator, in quite small footprints. Simply add volts and hold fingers in ears - no fancy circuitry required.
Mount them against something solid to maximise noise output.
I had a piezo i was testing with. to me it did make a good sound. But it was in my room and what i wanted was an alarm that would be audible in a crowded room of noisy people or that you could hear from outside or around the corner while being outside. Didn't know if the piezo would cut it. This might be a stupid question but can you add an amp to a piezo?
Drive with a NPN transistor with a 1500uH choke in the collector circuit, on the transistor's off cycle voltages across the piezo will soar to 10-20x Vcc.