Transistor, TRIAC and SCR Tester Circuit

circuit diagram of transistor triac and scr tester

In different types of electronic circuits, you might have seen multiple elements in common. Some of these commonly used semiconductor devices, without which electric circuits are almost incomplete are SCRs, transistors, and TRIACs. In broad electronics circuits when small elements fail to function, its consequence affects the performance of the whole circuit. So, before building the overall circuit, one must be wise enough to check the functioning of circuit elements to avoid future complications. The Transistor, TRIAC, and SCR Tester Circuit presented below assists us in a similar way to…

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Water Level Indicator Circuit using 7-Segment

circuit diagram of water level indicator

Normally we have seen on different websites, the overall circuit of the water level indicator uses a bar graph or a seven-segment display to indicate the water level. This type of representation using LEDs or digits for water level makes the observer which includes a large number of normal people, difficult to understand. A consequence of using those methods makes the whole effort inadequate. The circuit presented below surmounts this flaw and displays the water level using a seven-segment display, but there is a difference. The water level indicator circuit…

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Universal Crystal Test Circuit Using CA4007

circuit diagram of cristal test circuit

Crystal oscillators may fail to operate due to faulty design or faulty crystals. The circuit shown in figure 1 works well as a crystal tester for a wide variety of crystals and ceramic resonators over the 40-kHz to the 20-MHz range. Circuit Description of Universal Crystal Test Circuit Using CA4007 The oscillator in figure 1 is a Pierce type that operates at the crystal’s parallel resonant frequency and presents about 30 pF capacitance to the crystal. The IC1 (CA4007 A) contains three pairs of complementary MOSFETs with the first (input at…

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Electronic Room Thermometer Using Op-amp 741

electronic room thermometer using op amp 741

These days electronic room thermometer is very popular, though it is expensive. Now here we designed a simple and cheap electronic room thermometer using a temperature sensor and op-amp 741. Circuit Description of Electronic Room Thermometer using Op-amp 741 The heart of the circuit electronic room thermometer is IC1 (LM3911), which is used here as a temperature sensor. The output of this IC is variable according to temperature change. Its output increases at the rate of 10mV/0C rise in temperature. At 00C its output is 2.73V. The output from IC1…

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Operational Amplifier 741 Tester

circuit diagram of OP-amp 741 tester

The op-amp IC 741 is a DC-coupled, high gain differential amplifier with external negative feedback. IC 741 is characterized by the almost infinite open-loop gain (100,000), almost infinite input impedance (2MΩ), and almost zero output impedance (75Ω).  IC 741 is the most popular, cheap, and easy-to-use op-amp. Various type of circuit is designed using Op-amp 741 out of which some are voltage follower, current to voltage converter and vice versa, summing amplifier, etc. Various type of circuit based on op-amp 741 is already posted in bestengineeringprojects.com on the op-amp section.…

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Mains line frequency meter circuits

panel frequency meter circuit

Generally, the standard line frequency in some countries is 50HZ or in some countries 60HZ, which may vary from time to time. Due to this varying nature of frequency, sensitive equipment may start malfunctioning, and the requirement result we may not get. New here is a simple mains line frequency meter circuit designed and verified at BEP (Best engineering project) lab used to measure the frequency of AC mains. Circuit description mains line frequency meter circuit The circuit of the mains line frequency meter is built around timer IC2 (NE555),…

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All in One Tester Circuit

circuit diagram of handy tester

All in one multi-tester is quite expensive which may not affordable for every electronics beginner. Now, here is s cheap all-in-one tester circuit that can be used to test the condition of almost all the electronics components from the basic resistors to advance ICs. The circuit all in one tester is used to detect polarity, continuity, logic state, and also activity of multivibrator. Description of All in One Tester Circuit The circuit of the all-in-one tester is so simple that it can also understand by beginners. The circuit of all…

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Frequency Counter Using Digital MultiMeter

frequency counter circuit using digital multimeter

As being electronic hobbyists we love to design and verify various types of circuits, we often have to measure the output frequency. The device which is used for this purpose is called the frequency counter. A frequency counter is an electronic device that measures the frequency of electric and electronic circuits by counting clock pulse. The frequency counter available in markets is quite expensive and sometimes we cannot afford it. In BEP LAB we designed and verified a circuit called “Frequency Counter Using Digital MultiMeter” which will serve as an…

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A versatile Decibel Meter Circuit

audio application circuit

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…

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Transformer Test Circuit to Overcome Line Voltage Variation

transformer tester circuit

One of the initial production tests carried out on power transformers used in electronic equipment is the measurement of on-load voltages across their secondary windings. During this test, the basic requirement is that the voltage across the primary winding is maintained at the rated line voltage. But in practice, there will be variations in the line voltage and its effect will be reflected on the secondary side. Hence the test carried out will have their internal error. Circuit Description of Transformer test circuit to overcome line voltage variation Here is a…

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