Dog Repellent Ultrasonic Circuit 2

 

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When we hear the word “Ultrasonic” we often refer it to bats and dolphins communication. Technically, “Ultrasonic” applies to sound that is anything above the frequencies of audible sound, and includes anything over 20kHz. Frequencies used for medical diagnostic ultrasound scans extend to 10 MHz and beyond. This dog repellent ultrasonic circuit will chase away angry dogs. It comprises of a 555 timer IC, a speaker/piezoelectric and a little ferrite transformer.

The main part of this circuit is a 555 timer IC. A 555 timer IC is an integrated circuit (chip) used in a variety of timer, pulse generation, and oscillator applications. The 555 can be used to provide time delays, as an oscillator, and as a flip-flop element. Derivatives provide up to four timing circuits in one package. You can use the 555 effectively without understanding the function of each pin in detail. Frequently, the 555 is used in astable mode to generate a continuous series of pulses, but you can also use the 555 to make a one-shot or monostable circuit. The 555 can source or sink 200 mA of output current, and is capable of driving wide range of output devices.

To use this circuit adjust 4k7Ω Resistor at resonance frequency of the piezo transducer for maximum amplitude of the repeller ultrasonic sound. At 11 KHz to 22kHz this can reach a value of 10Vpp and the buzzer is a passive one (without generator).

Note: Ultrasonic frequency must be set with a dog nearby.

Component:

4k7Ω Resistor
10uF Capacitor
10nF Capacitor
1k2Ω Resistor
4k7Ω Potentiometer
Piezo
NC Push Button

Dog Repellent Ultrasonic Circuit 2 – [Link]

PROPEL Program Seeks Startups with Innovations in Distributed Sensing & Intervention

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Fraunhofer TechBridge, Greentown Labs launch program to accelerate energy innovations’ path to market

Boston, MA – April 16, 2015 – Access to external feedback early in the development process is critical for building successful innovative products. For large companies, such access is easily obtained; for startup companies, however, industry feedback is hard to come by. To assist entrepreneurs in that effort, Fraunhofer TechBridge (a program of Fraunhofer CSE) and Greentown Labs have teamed up to launch PROPEL, a six-month program for startups to refine their prototypes, obtain customer feedback, and develop their businesses for success in the market.

With the vision of a smarter, interconnected world, PROPEL is seeking complementary innovations in self-powered Wireless Sensor-Actuator Networks that can radically change how we interact with our surroundings. The program, sponsored by Shell GameChanger, is seeking startups that are:

  • Creating technologies for distributed sensing and actuation networks;
  • Developing prototypes and/or integrated systems for customer validation;
  • Looking to develop strategic partnerships with industry as a potential go-to-market strategy;
  • Interested and able to relocate to Greentown Labs in Somerville, MA for the duration of the program.

(more…)

Arduino measures heart beat rate from fingertip

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In this article Raj over embedded-lab.com shows us how to measure our heart rate using Arduino UNO, his Easy Pulse Plugin and 4-digit SPI seven segment LED display module. It computes the heart rate by processing the analog pulse signal output from the Easy Pulse Plugin sensor and displays it on the seven segment display module.

Arduino measures heart beat rate from fingertip – [Link]

RELATED POSTS

3A Power supply for USB devices

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Jayakody published a new project, a 3A Power supply for USB devices:

This is 5V 3A power supply to drive two USB based devices simultaneously. This power supply is design around LM2576-5.0 switching regulator IC and the main reasons to choose this IC is its low parts count, small heat sink requirements and its inbuilt current limit protection feature.
We specially design this power supply to work with development boards / single board computer (SBC) platforms such as Raspberry Pi, Banana Pi, BeagleBone, etc. This power supply can also be used to provide power to USB OTG peripherals over USB Y cables. We test this setup and got successful results with Huawei Ascend P6 mobile phone.

3A Power supply for USB devices – [Link]

DIY Speedometer and Odometer

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by electroguyz:

Hey guys, this a instructable of how to make a bike speedometer.Yeah,you read it right the one that we use in car but only for 10$ .Well the first this for you to know is that this is the collaborated project of Mr_DIY_Electrician and paurushthemaker .So back to topic our project is all about a speedometer which has 3 modes as follow:-

DIY Speedometer and Odometer – [Link]

RELATED POSTS

Multi-pole industrial relays provide more possibilities

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Switching of three-phase motors or a realization of a sophisticated installation is a breeze with industrial relays Finder.

As we know, a relay is a very versatile component, able to realize also various “sequential” circuits, when for example by switching one relay we´ll switch on a target device and at the same time we´ll enable (or disable) switching of another relay. In these case, it´s an often demand for a relay to have a sufficient number of poles. Majority of such “logic” circuits can be realized even with a common 1-2 pole relays, but it´s not always economical and it also brings another costs for solution of supplying and protection of logic circuits.

Industrial relays Finder series „55“ and „60“ are suitable for a construction of such more complex circuits or for switching of three phase devices.

  • Finder 55 – miniature industrial relay for a PCB or for socket, 2-4 poles, 7-10A (switching current up to 20A), 250/400VAC,
  • Finder 60 – a more robust industrial relay for a socket, 2-3 poles, 10A (switching current up to 20A), 250/400VAC,

(more…)

LT8640 – 42V, 5A Synchronous Step-Down Silent Switcher

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The LT8640 step-down regulator features Silent Switcher architecture designed to minimize EMI/EMC emissions while delivering high efficiency at frequencies up to 3MHz. Assembled in a 3mm × 4mm QFN, the monolithic construction with integrated power switches and inclusion of all necessary circuitry yields a solution with a minimal PCB footprint. An ultralow 2.5μA quiescent current—with the output in full regulation—enables applications requiring highest efficiency at very small load currents. Its 3.4V to 42V input voltage range makes it ideal for automotive and industrial applications.

LT8640 – 42V, 5A Synchronous Step-Down Silent Switcher – [Link]

 

RoomMote – Control the color and sockets of your Room

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by rohitg.in:

Buzz..Buzzzz..buzzzzzzzz .. That is how a lone mosquito irritates you in the middle of the night trying to convince you that his lullaby is helpful. Insignificant or not, But truly that is the underlying inspiration for this project. The Mosquito repellents have this obnoxious smell that I would not like to sleep in and these loner mosquitoes who just piss me off by buzzing in the ear, you have to choose a lesser evil. Obviously, I turned ON the repellent and in a while it goes off but the smell starts building up and I am too lazy to turn it back OFF, leaving the warmed blanket on a chilly Delhi December Night. The nocturnal dilemma .

RoomMote – Control the color and sockets of your Room – [Link]

Playing with analog-to-digital converter on Arduino Due

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Piotr wrote a post on his blog about using some of advanced capabilities of ADC in Arduino Due:

Today I’m going to present some of more advanced capabilities of ADC built in ATSAM3X8E – the heart of Arduino Due.
I like the Arduino platform. It makes using complex microcontrollers much simpler and faster. Lets take for example the analog-to-digital converter. To configure it even on Atmega328 (Arduino Uno/Duemilanove) you must understand and set correct values in 4 registers. And it can be much more in complex device, like 14 in ATSAM3X8E (Arduino Due)!

Playing with analog-to-digital converter on Arduino Due – [Link]

RELATED POSTS

Design Your Own PCB Business Card

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by Proto G @ instructables.com:

In this instructable I am going to show you how to make your own printed circuit board business card. I feel that these business cards will really help you stand out from the crowd and make a great impression. It might even add one more skill to your resume. Everyone that I have given these cards out to has been really impressed and thought it was a great idea. I have regular business cards as well and I only selectively give out my circuit board cards. You can take it to the next level by soldering different circuits on the cards. I made one of my cards into a standalone Arduino.

Design Your Own PCB Business Card – [Link]