Among different types of amplifiers available in today’s technical world, sometimes we get stuck with the audio frequency amplifiers which provide flat frequency low-frequency notes should be amplified more than the high-frequency note stable). The provision of bass treble is accordingly made to gratify the users and to compensate for the effect of noise that comes along with the signal. The bass treble combination is given a single name; tone control. Circuit Description of Bass Treble Circuit Talking about the bass treble circuit, it is comparatively much simpler and gainful.…
This electronic project, Add on Device For Telephone has multiple applications when used with the telephone lines. Since it is added parallel on the telephone system, it is called add-on device. The circuit add on device for telephone supports three modes of operation: on-hook, off hook, and ringing modes. It also provides the audio-visual indication of these operations. Using the relay, add on device circuit can connect the telephone to a CID (caller identification device). It can also be used to indicate tapping or misuse of telephone lines with the…
An interesting circuit design that is also used as a wireless telephone amplifier, is demonstrated below which has been proven very useful in prying on a telephone conversation and therefore is termed a phone broadcaster circuit. The more amazing or we can say a comforting fact about the phone broadcaster circuit design is that it draws the power essential to operate the circuit directly from the active telephone lines. Therefore, it avoids additional expenses in external battery and prevents the circuit from the extra bulkiness of other power supplies. Circuit…
The most important quantity that one comes across in the study of electrical and electronic is signal either it cans voltage or anything else. For successful operation, installation and repair of electrical and electronic equipment, it becomes necessary to measure different aspect like voltage signal, current etc and the instrument used for the measurement of these quantities is called meter. Systematic fault finding and electronic appliance servicing requires the use of certain service tests and measuring instrument and equipment. Correct use and proper handling of these test instruments is as…
Here is a simple project called listening bug circuit using 741 using the most popular op-amp IC 741. This circuit can be used for spying because by using this circuit we can hear any conversation held in any other room or we can say using this circuit one can hear the conversation held in another room. This circuit can also be used for baby monitoring. Also, check our Listening Bug Circuit using op-amp LM386. Description of Listening Bug Circuit Using 741 The circuit of the listening bug shown in figure…
Complete fiber optic systems are finding widespread use in all types of applications figure 1 provide a very simple fiber optic telemetry system using NE555 that can be used in a variety of telemetry application essentially. The transmitter is an astable oscillator using the popular NE555 (IC1). Circuit Diagram of Fiber optic telemetry system Using NE555 The variable resistance LDR1 contract the rate of the pulse applied to the LED. LDR1 can be any variable resistance transducer such as a strain gauge for pressure sensing, a thermistor for temperature sensing, or…
Here is a circuit for an miniature IC organ using 3-volt AF amplifier IC TDA2822. Frequency of the AF sound generated depends on the capacitor between pin 1 and pin 7 of IC. When switch SW1 to SW10 are pressed, different audio tones are heard from the speaker. SW1 to SW10 are small push-to-on switches. Pin 2 of IC is connected to positive terminal of 3-volt battery. Two pen cells connected in series can be used to power this circuit. Satisfactory loud sound will obtained at 3-volt supply. Note: Capacitors…
Here, we have more then 30 very basic electronics project which are easy to understand and easy to build. The knowledge level for complete the basic electronics project posted in this section is basic level, and even understood by non electronics geek. Basic electronics projects section includes projects which can be easily build using very few electronic component (resistors, capacitors, ICs etc). Also the knowledge level required for doing this types of project is of entry level or we can say basic level. Most of the projects posted in this…
A decibel meter is an instrument to measure levels of the input signal(s) in decibel units. The main areas of application of decibel meter are audio level indicators, record level indicators, spectrum analyzers, and the like. The project “A versatile decibel meter circuit” shows here provides a resolution of 20 steps. Although the steps are linear, they are calibrated with corresponding decibel value so that it suits most of the requirement. Description of Versatile Decibel Meter Circuit The schematic diagram of the versatile decibel meter circuit is shown in figure…
Here is a circuit for a pocket radio using one IC LA4510 and three transistors. This circuit differs from ordinary circuits at the audio stage only. Here a small 9-pin IC LA4510 is used. It replaces three transistors, a driver transformer, and many other passive components. The amplifier circuit needs only one resistor! At zero signal level, this circuit draws 8-10 mA current only. With a 3-volt supply, this circuit can give 200 mW output power. For making this radio you may buy an ordinary pocket radio PCB and assemble…
