Free electronic circuit design and schematic diagram
A condenser microphone is different from dynamic microphone. The condenser microphone, the diaphragm is assembled close to a rigid backplate. This microphone need a battery that is connected to the rigid backplate and the diaphragm to charge or give an electrical potential between the metals. The response of diaphragm to sound is changed since the diaphragm change. The displacement of […]
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A dynamic microphone is an example of dynamic transducer. The principle of dynamic transducer is a movement of a thin metallic diaphragm because of sound wave. This diaphragm attach coil of wire. Based on Faraday’s electromagnetism law there will current flow caused by the motion of within the field. The motion speed affect the current amount that is produced by […]
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This is a hearing aid circuit with 1.5v supply. This circuit is used to detect very faint sounds, then deliver the sounds to an 8 ohm earpiece. This circuit requires 1.5v input voltage, need only a single cell battery. Here is the schematic diagram of the circuit: This circuit can be assembled in a small board, or you can even […]
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This is circuit of Clap Triggered Switch. When the circuit detects tap, or short whistle or a clap, this circuit will toggle the LEDs. 33k and 5K6 charge The second 10u. The negative excursion of the waveform takes the positive end of the 10u towards the 0v rail, when a sound is detected. the two 1N4148 diodes will be pulled […]
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This is a decibel meter circuit. This circuit is used to measure sound pressure level (SPL) from about 60 to 70 dB. In this circuit, transistor stage and one LM324 op-amp section are used to amplify the sound that is picked up by an 8 ohm speaker. As voltage comparators, the circuit uses The remaining 3 sections of the LM324 […]
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They were missing a VOX if we are take a look at some of the budget priced HF transceiver. It would certainly be nice to have VOX capability although most of these budget priced transceivers performed admirably. The figure below show us a basic VOX circuit which will perform very well once the VOX level is set correctly. This is […]
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Feedback in public address amplifier is something that should be avoided. The ideal solution is by adjusting the microphone and the speaker position, but it’s not always possible in many situation. Using frequency shifter to change the output frequency 10Hz lower than the input frequency can solve the problem, but it’s too expensive for a low cost public address system. […]
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