practical joke

ive used this circuit here before to drive a friend of mine insane. i should like to improve on it a bit though.

the way it works is that wen there is light, the buzzer makes no sound, but wen there is no light, the buzzer turns on, thus driving the victim insane because they cant find it in the dark, and wen the light is on, there is no sound :twisted:

neway, i would like to make a 30 second or so delay so that its not instantaneous with turning off the light. i was thinking of putting a capacitor between ground and the base of Q1. the idea behind this being that the cap would be sucking up current (haa haa, i got bleeped because i said s u c k i n g), and there wouldnt b enuf 2 turn on the transistor until the cap is "filled up". of course there would probly be a resistor in series with the capacitor and on the base of the transistor for this to work. also a drainage resistor in parallel w/ the cap so that wen the light goes on it turns off.

am i on the right track here?

thats awwsome i am gonna make one too hahahahaha :twisted:

Like it! :lol:

it wod be cood if you wod build it in an radio or somting


I tryed to make an thing that beeps wenn it detects an IR signal (so it beeps at TV remotes) but the damn fototransistor had a to small angle so its saw only the directly in from of it and it wasent much sensitive too