Electroscope

This Circuit can measure voltage of electrostatic charge.

Source : Elektor Circuit

This is by far the easiest and most useful. The other two both require you to mount a thin strip that is used as the indicator, and in both cases mounting this strip is a big hassle and the resulting assembly does not work very well. This scope works out of the box, and works perfectly. The readings are sensitive and reproducible. Check it Out!

Electronic Stethoscope Circuit

Using 1 BC548 Transistor ,and several passive components , and Buzzer 1 also 4,5 V Battery . Source Elektor Electronic

The modern digital stethoscope as The 3M Littmann CORE Digital Stethoscope features the outstanding acoustics, comfort and quality of a Littmann cardiology-grade stethoscope enhanced by powerful digital technology. Features like up to 40x amplification* and active noise cancellation can help you auscultate with greater confidence. The Littmann CORE Digital Stethoscope connects with Eko software on a smart device** to visualize, record and share data.

*40X amplification based on comparison of analog versus electronically assisted amplified listening with maximum volume at the peak frequency(125 Hz). Check it Out !

Digital TV Antenna

Digital antenna TV has to have capable reception on TV Band Digital TV frequency , from 470-862 MHz.

We can design with Yagi model, Logarithmic antenna Design , Fractal Antenna design or other design that proven can receive with good quality on this band. with frequency reception, we can design this :

862 - 470 = 392 , 1/2 Lambda will be , 490 + 392/2 = 666 Mhz

For Yagi antenna , I use calculation design from K7MEM.com
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or you can also get design from Su and Chang http://www.jpier.org/PIERL/pierl12/14.09102302.pdf

The implementation looks like this :

I have tried the Su and Chang design , with good reception at Digital Terrestrial TV Channel and average quality in analog TV channel reception.

DIN rail ARM7 Ethernet/USB Subsystem (LPC2138)

This package is ideal for industrial use, facilitating quick connection and relocation
DIN rail mountable and compatible with OKW Railtec C-5 enclosure
On-board BASIC compiler runs 30 times faster than interpreted BASIC

SUCCESS

Astronomy

A NASA astronomer selected ARM Ethernet controllers to create a one-off error-correction system for an infrared telescope.

Our secondary mirror assembly would occasionally jerk. So we constructed a system using eight BMA180 accelerometers, each attached to an ARMWeb SBC.
These were then programmed to acquire and stream the accelero- meter data to a Linux server. The server would save and graph the data in real time. When an 'image jump' was recorded, this accelero-
meter data was analyzed to help identify the faulty mechanism.