Matt circuit

‘Hello… HELLO! Are you deaf? Do you have disco ears?’ If people ask you this and you’re still well below 80 , you may be suffering from hearing loss, which can come from (prolonged) listening to very loud music. You won’t notice how bad it is until it’s too late, and after that you won’t be able to hear your favorite music the way it really is – so an expensive sound system is no longer a sound investment. To avoid all this, use the i-trixx sound meter to save your ears (and your neighbor's ears!). With just a handful of components, you can build a simple but effective sound level meter for your sound system. This sort of circuit is also called a VU meter. The abbreviation ‘VU’ stands for ‘volume unit’, which is used to express the average value of a music signal over a short time. The VU meter described here is what is called a ‘passive’ type. This means it does not need a separate power supply, since the power is provided by the input signal. This makes it easy to use: just conne...

Description Free circuit dot com presents the digital tester circuit,this circuit is checking voltage in TTL with display by 7 segment. I think the circuit will be using for you apply to your electronic projects. The function of circuit is sorting TTL voltage with resister to drive transister BC547B after that it will be drive IC model 74SL00 to turn on each segment of 7 segment display. Part List IC 74LS00 1 pcs. T1-T3 BC547B 3 pcs. R1,R2,R5,R6 10K ohms R3 47K ohms R4 8.2 K ohms 7 segment 1 pcs. Source -http://www.free-circuit.com/2012/11/14/digital-ttl-voltage-testing-meter-circuit/

This is an audio meter, a kind of decibel simpler, used to measure the sound directly in the circuit or a sound output device. It is very simple, using only two transistors BC107, potentiometer VR2 adjusts the input level and the level of VR1 VU. This meter audio should only be used for bench testing and should not be used for calibration. Simple Audio Meter Circuit Diagram Simple Audio Meter Circuit Diagram

Description : Even if the digital multimeter have dominated in a lot of applications, in the measurement, exist the need for existence of instruments of clue in various appliances, voltage and current, as in power supply or elsewhere. The circuits that give make this precisely the work, measure the voltage in terminal a circuit and the current that passes in his. The circuit does not present particular difficulties for somebody that has a small experience. The two circuits are the himself, with a small difference only in their input, when they have they measure voltage or current and in connection that concern decimal point [ dp ]. In the department of input IC1 and IC3, exist the CA3161E, that is a A/D Converter for 3-Digit Display. In the drive of Display IC2 and IC4, exist CA3161E, that is a BCD the Seven Segment Decoder/ Driver. As it appear in Fig.1, that concern the voltmeter in input [ + IN ], exist in series a what resistor R1 in combination with the R3 create a voltage divide...