Simple Signal Injector Circuit

circuit diagram of signal injector

Here is a project of a Simple Signal Injector Circuit. Don’t think it’s just “another one”; see the advantages it offers over some other injectors: Commercial injectors working on 1.5V are rather large in size to be carried in a shirt pocket. You can carry this injector quite easily in a shirt pocket because the whole device can be assembled in a pencil cell holder. This circuit will give you a battery life of about two a single pencil cell. Most important of all, this injector will cost you at…

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Relay Tester Circuit

circuit diagram of relay tester

Here is the relay tester circuit using timer IC 555 which is used to measure pull-in and release voltage of relays ranging from 6V to 28V DC. Relays are probably the simplest electromechanical devices, yet they are the most important components of many industrial and domestic electrical equipment. All too often, it is a hardship for the equipment manufacturers to discover that the commercial quality relays of similar types have a wide range of operating voltage. Many times, it is found that the relay contacts will not close properly. Many…

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Single Phasing Preventer Circuit

installation of the preventer

If we have been familiar with machinery, we all know how important it is to follow safety measures to mitigate injuries and accidents. A single phasing preventer circuit is one of the solutions we can look forward to. The phrase ‘preventer circuit’ itself portrays it. The single-phase preventer circuit is also a high low and unbalanced-supply voltage cut-off relay. To ensure complete safety for 3-phase machinery, the preventer circuit has been known to be handy. Generally, an induction motor burns out due to excessive voltage during an off-hour, a very…

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Frequency Counter Schematic using Microcontroller AT89C51

circuit diagram of frequency counter

Frequency Counter Schematic using Microcontroller AT89C51 is a simple yet mostly used frequency counter schematic used. The reason behind its simplicity also lies somewhere in the fact that this project uses only two components-AT89C2051 microcontrollers and a 16*2 LCD. Frequency is a crucial subject matter in every project. Precise and accurate frequency generation is another challenge we face in varieties of project design. As per the design of this project, this circuit can withstand frequency ranges between 1 Hz to ~16.5 Mhz, and the rest depends on the characteristics of…

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Data Logger Using Computer

circuit diagram of data logger using computer

The project described here is a simple Data logger project using a computer that can be used in physics laboratories with the purpose to automate simple experiments or monitor slowly varying physical variables such as temperature. Physics can be interesting and boring at the same time. It might get boring for the reason that most of the physical parameters vary frequently with values or physical properties they execute and we lack the apparatus to measure them accurately. This leads us to the fact that we cannot get a precise measurement.…

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5 State Digital IC and Circuit Tester

circuit diagram of 5-stage digital IC and circuit tester

Quite often electronics engineers and technicians come across the problem of fault-finding or testing electronic circuit boards full of digital integrated circuits. A handy and quick look-tool ‘5-State Digital IC and Circuit Tester’ for such an analysis is a logic probe that does the job faster and easier by just touching this probe to different pins of various ICs and observing the logic levels. Introduction to 5-State Digital IC and Circuit Tester Most of the commercially available logic probes show only two distinct levels of logic ‘0’ and logic ‘1’ corresponding…

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555 Timer IC Tester

circuit diagram of 555 ic tester

NE555 Timer IC  is very popular and one of the most commonly used components in electronics circuits. NE555 Timer IC is also called Ideal IC since it offers multiple features like multipurpose functionality, low power consumption, small size, and durability. When we work on a particular project and it doesn’t work the way we wanted, before the circuit we doubt whether the IC used, is working or not. More or less, blaming IC is reasonable since IC is the combination of many more components or IC itself is a combination…

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Capacitor Tester cum Flasher

capacitor tester circuit diagram

Capacitors are one of the basic components of any electronic project. Now, here we taught you, how to test capacitor whether is short, open or working. The simple circuit of the capacitor tester is built around two general-purpose NPN transistors. This circuit posted here is used to test capacitors up to 1000 µF. The capacitor to be tested is connected at points A and B as shown in the circuit diagram (positive terminal at point B where negative terminal at point A). Working of the circuit Capacitor Tester cum Flasher When…

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Electronic Thermometer Circuit

electronic thermometer using 741 IC circuit

A number of measurement circuits have appeared on this website. The project posted here is of Electronic Thermometer Circuit using op-amp 741. This circuit is suitable to measure temperature from 00C to 500C using a linear scale am-meter. The range can be extended up to 1000C using 100 microamperes. Circuit Description of Electronic Thermometer Circuit using 741 IC The circuit is self-explanatory for the experienced hobbyist and performs its task with a minimum number of components. The operational amplifier is used in compactor mode. The diodes D1 and D2 are used…

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Digital Voltmeter (DVM) Circuit Using ICL-7107

circuit diagram of digital voltmeter

A digital voltmeter (DVM) Circuit displays measurements of AC or DC voltage as discrete numerals instead of a pointer deflection on a continuous scale as in analog instruments. Digital Voltmeter Circuit is a versatile and accurate instrument that is employed in many laboratory measurement applications. Because of the development and perfection of the IC modules, the size, power requirement, and cost of the digital voltmeter as been drastically reduced, and therefore, digital voltmeter circuits can actively compete with the conventional analog instruments in price, portability, and accuracy. Here, in this…

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