I am working on building a piezo screamer myself. I have found multiple circuits on the web, but all of them have dozens of parts.
I disassembled one from Radio shack and found about 4 total parts. These units have an 8 pin chip with CIR8821C written on it and a three pin transformer to boost the piezo. How would I find out what these part are? A web search yielded nothing.
I would like to trim my parts down and find the magic spot on the web that sells these chips.
Any help would be appreciated..
John