DIY Hearing Aid Circuit using 555

diy hearing aid circuit

The general circuit of Hearing Aid available over the internet used a normal transistorize circuit thus it consumes more power. So, here we are concentrated to design a circuit that consumes less power, DIY Hearing Aid Circuit using 555. For that, the circuit present here of DIY Hearing Aid Using 555 has an automatic triggering mode which consumes 96 mA at the time of amplifier trigger or you can say when sound is detected else it consumes only 6 mA which is very less. Other than less power consumption the…

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Dual Polarity 5v from 9v Battery

simulation of plus minus 5V supply

Almost all electronic devices used in electronic circuits need a dc source of power to operate. The source of dc power is used to establish the dc operating point for the passive and active electronic devices in-corporate in the system. This day almost all circuits 5V regulated power supply but an operational amplifier requires a dual power supply (positive and negative) for proper operation, while we are using the battery power supply for a circuit then it would be difficult to get a dual polarity power supply. In order to…

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Simple Battery Changeover Relay

circuit diagram of battery changeover relay

It is economical to use a battery eliminator but with frequent power failure in most developing countries, it becomes annoying to change over from battery eliminator to battery operation every time the electric supply fails. Thus, we had designed a simple battery changeover relay. A simple way to avoid the nuisance is by connecting the battery and power pack in parallel. But the advantage with such a system is that when the eliminator voltage falls, even slightly (say from 6V to 5V), though the performance of the set remains unaffected,…

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Wireless Temperature and Humidity Indicator for Fridge

circuit diagram of receiver unit of wireless temperature and humidity indicator or fridge

There are various types of circuit used to indicate the temperature and humidity of fridge but it cannot measure relative humidity accurately. Because at the time of door opening of fridge relative humidity will rise or fall due to moister of surrounding. Thus, we had posted here “Wireless Temperature and Humidity Indicator for Fridge”. Here, we had posted a simple, small and handy wireless device which is used to measure temperature, humidity and relative humidity from inside the fridge. The circuit posted here used RF technology to transmit and receive…

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Rotation Sensor using 555 IC

circuit diagram of rotation sensor using 555IC

In this section, we discuss another application of the most popular IC, the 555 timers. Introduced in 1972 by the Signetics Corporation as a bipolar integrated circuit, the 555 is also available in CMOS technology and from several manufacturers. There are various projects we had already posted in the timer IC 555-based projects section. Now, we have come up with another interesting project called rotation sensor using the most popular IC of all time 555 Timer IC. When more conveyors or equipment are used in the processing system and anyone…

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Zener Diode Tester Circuit

modified circuit diagram of zener diode tester

One of the most important uses of the zener diode is in making the constant voltage power supply. Its works are based on the fact that in the reverse breakdown (Zener) region, a small change in voltage across the zener diode produces a very large change in current through the circuit but the voltage across the Zener remains constant. In this article, we have posted two different circuits to test the zener diode i.e. general Zener diode tester circuit and modified Zener diode tester circuit Here, is a circuit that…

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DIY Strobe Light Circuit

circuit diagram of DIY strobe light

Here is one another application of one of the most versatile IC NE555, the DIY Strobe light circuit. A strobe light is also called a stroboscopic lamp and is used to produce a regular flash of light. The general strobe light has a very high flash energy of about 150 joules and very few milliseconds of discharge time. Due to this property, it emits flash power of several kilowatts. Various types of strobe light circuits using xenon flash lamps, flash tube, LEDs, etc. posted on bestengineeringprojects.com are listed below:- High Brightness…

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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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Eight Channel Audio Mixture with Multiple Control

circuit diagram of audio mixture with multiple control

Here is simple circuit of eight channel audio mixture with multiple control using IC TDA 1524A and 747 to mix eight individual sound. The PCB for soldering side and component side is also given. The conventional sound systems involved recording of sounds from several musical instruments, each played by different musicians using only a single microphone. Then, in order to balance the sound tone, they had to alter the positions of musicians according to the microphone. Due to which people started to record directly to stereo master tape. However that…

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Low Power Audio Amplifier Using LM386

circuit diagram of low power audio amplifier

The circuit and PCB Design of Low Power Audio Amplifier using LM386 is posted here which used to drive at most audio power of 1 Watt. LM386 is an low voltage, battery operated power amplifier designed for application where low voltage is main concern. The main advantage of using LM386 is it does not requires any ground reference voltage and it’s output is automatically biased to 1/2 of supply voltage. Circuit Description of Low Power Audio Amplifier Using LM386 To derive at most audio power of 1 watt at the…

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