High Quality Intercom circuit
The intercom circuit operates as a simple yet effective communication system, leveraging the LM380 audio amplifier for enhanced sound quality. The use of two transistors as microphone preamplifiers allows for adequate amplification of the audio signal from the microphones, ensuring clear audio transmission.
Each intercom unit is designed to be self-contained, featuring its own power supply to provide the necessary voltage for the components. The PTT relay circuit enables users to activate the microphone and transmit audio when the button is pressed, allowing for hands-free operation when desired.
The connection between the two units is achieved using only two conductors, which simplifies installation and reduces material costs. The low output impedance of the microphone preamplifier mitigates the need for shielding, making it feasible to utilize standard two-core speaker cable or bell wire for inter-unit connections. This design consideration not only lowers the overall cost but also enhances the ease of installation, making it accessible for various applications.
In summary, this intercom circuit is an efficient solution for audio communication, combining affordability with satisfactory sound quality, while its design promotes straightforward installation and operation.This is an intercom circuit which use LM380 as the audio amplifier and 2 transistors as the microphone pre amplifier. The sound quality will be good enough with low cost building. 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 circui
t. 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. 🔗 External reference
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