Matt circuit

Description: A very high quality intercom, which may also be used for room monitoring. Circuit diagram Notes: This circuit consists of two identical intercom units. Each unit contains a power supply, microphone preamplifier, audio amplifier and a Push To Talk (PTT) relay circuit. Only 2 wires are required to connect the units together. Due to the low output impedance of the mic preamp, screened cable is not necessary and ordinary 2 core speaker cable, or bell wire may be used. The schematic can be broken into 34 parts, power supply, mic preamp, audio amplifierand PTT circuit. The power supply is designed to be left on all the time, which is why no on / off switch is provided. A standard 12 V RMS secondary transformer of 12VA will power the unit. Fuses are provided at the primary input and also secondary, before the rectifier. The 1 A fuse needs to be a slow blow type as it has to handle the peak rectifier current as the power supply electrolytics charge from zero volts. The microphone...

I for one can't imagine entering into my daily commute without the sound assistance of a good auto sound system. Music in the morning is as necessary for me as oxygen and caffeine. If I live without any of those above my day is already up and running with wrong foot first. Music is a very important part of any given day for someone like me. My wake up call in the morning comes in the form of my favorite radio station and from that point on I have music as my companion for the vast majority of my morning routine. That is of course with the exception of children and husband and some of their more insistent demands for food, money, and last minute homework crisis. I will gladly take my music and tea most mornings and skip the drama. The point of all this is that I am not alone in my morning preference. If I were there wouldn't be so many variations of the music driven alarm clock. Today you can even have CD player alarm clocks in order to get you up and running to your favorite tu...