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Showing posts with the label Tone

Relay Switch Activated by Tone and Signal

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The essence of the circuit is for the input of tone and signal to provide an activation for the relay switch. Relay – an electrically operated switch where the current flowing through the coil of the relay is creating a magnetic field which attracts a lever and changes the switch contacts, thereby making its state open or close BC214 – a complementary silicon planar epitaxial transistor used in AF small signal drivers and amplifiers as well as for low noise preamplifier applications due to its feature of good linearity of DC current gain LM741 – a general purpose single operational amplifier with features such as offset null, compensated internal frequency, voltage range with high input, good stability of temperature, and protected from short circuit The use of relay will allow the circuit to switch from one condition to another. It can also be referred to as a form of an electrical amplifier since it is able to control an output circuit of higher power than the input circuit. There ar...

Build a MT8870 DTMF Telephone Dial Tone Decoder Circuit Diagram

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 Build a MT8870 DTMF Telephone Dial Tone Decoder Circuit Diagram. This is a  simple MT8870 DTMF Telephone Dial Tone Decoder Circuit Diagram . In this circuit one common DTMF receiver IC is the Motorola MT8870 that is widely used in electronic communications circuits. The MT8870 isan 18-pin IC. It is used in telephones and a variety of other applications. When a proper output is not obtained in projects using this IC, engineers or technicians need to test this IC separately.  A quick testing of this IC could save a lot of time in research labs and manufacturing industries of communication instruments. Here’s a small and handy tester circuit for the DTMF IC. It can be assembled on a multipurpose PCB with an 18-pin IC base. One can also test the IC on a simple breadboard. For optimum working of telephone equipment, the DTMF receiver must be designed to recognize a valid tone pair greater than 40 ms in duration and to accept successive digit tone-pairs that are greater than ...

Tone control low noise circuit

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Tone control or pre-amplifier is an amplifier circuit supporters. Sometimes some of us do not know where a good amplifier, a raft alone and the results are not much different or even the same. Therefore we must know the character of the advantages and disadvantages of each amplifier equipment. Tone control low noise here does not mean without noise, but noise compared with the lowest tone control on the market, for example Ronica transistor 4, TL-084, TC-2 LM833 etc. CSE | Circuit Schematic Electronics Jump toexplanation of each component ... Potensio 1 serves to regulate the intensity / level of the incoming signal is assisted potensio 2 as balance / counterbalance. Potensio 2 is still installed and is usually an optional component. 1-2uF/250V capacitor R1 is actually a brand name,but I prefer to replace it with a 1K resistor / 5% normal for reasons to avoid hum and interference sensitive. R2 R3 while minimizing interruption to adjust the impedance OP-amp 1. R4 and R5 serves to increa...