My Light Diagram

My wife was working on a doctoral dissertation and needed to do some field work involving personal interviews in various settings. What would be the best way, technically speaking, to record the interviews? To pass a tape recorder or microphone back and forth seemed too awkward and clipping wired microphones to interviewees didn’t make for a particularly informal atmosphere. Radio microphones seemed overly expensive, too. After some thought, I can up with the "Room Recorder", an add-on microphone preamplifier circuit for use with a tape recorder. While I don’t make any great claim to originality for the circuit, it has produced first class results over one year of interviews and might prove useful to anyone doing similar work. Circuit diagram: Room Recorder Circuit Diagram The preamplifier was plugged into a Sony Cassette-Corder (any similar device will work) by means of a long, screened microphone cable and placed in a central location in a room or on a bench. The circuit wi...

That is how a lone mosquito irritates you in the middle of the night trying to convince you that his lullaby is helpful. Insignificant or not, But truly that is the underlying inspiration for this project. The Mosquito repellents have this obnoxious smell that I would not like to sleep in and these loner mosquitoes who just piss me off by buzzing in the ear, you have to choose a lesser evil. Obviously, I turned ON the repellent and in a while it goes off but the smell starts building up and I am too lazy to turn it back OFF, leaving the warmed blanket on a chilly Delhi December Night. The nocturnal dilemma . [ ]

The room bells are used to produce a ringing alert sound so that the resident comes to know that a visitor is there on the door. Many homes have two doors for entering. So at times it is confusing for the resident to find out on which door is the visitor present. This room bell circuit produces two different sounds can be used simultaneously on both the doors. The room bell circuit is made up of CMOS LSI designed UM3561 IC which consumes less power. It is commonly used in toys and alarm watches because of its low cost. A compact sound module can be constructed using this IC. It includes oscillator and selector circuit and only few components are required to be added externally. It also contains a programmed ROM to produce siren sound. When the switch S1 or S2 is pressed, the pin1 or pin5 of the IC1 receives the high signal which is used to drive the transistor that is connected to pin3 of IC1. Hence the speaker gets the supply and IC1 produces the sound of siren so as to indicate...