With the best wishes for you. I found your address and browsed your website. I have a question and hope to take your help and answer.
I need to good metal detector’s circuit and I find several in the web, any of them worked ? what is a problem in them and where can I find one that works with best depth? Could you design or point the mistake in some circuits? Thank you for your answer beforehand.
delabs – See my Related Page at Metal Detector Projects
Mail from AS
Thank you for your answer and sites. But some of them that are professional namely “twin loop” built but it has problem and didn’t work.
I think it may be a indicated, there is a problem with them. How can I make it correctly? could you proper design such circuits?
I am not professional and of you do, I will pay for your works.
Reply from AS
If you clearly specify what you want with a drawing, And indicate what you may be able to pay and your contact details too…….
Then, I will publish your request in my site. People visiting my pages may contact you. You can Try it out, I may not be able to help now.
(PS – You can offer a solution to AS’s Problem, post your design page details, All Comments are moderated, Commercial or Business comments will be deleted, designers can indicate homepage.)
Yes, there were electric lights powered by central stations before Edison’s! Carbon arc lamps saw extensive use throughout the USA and the world from the late 1870s on. – Charles Brush
Museum Of Electricity – Charles Brush
The General Electric Company was formed in 1892. It was the result of a meger between the Edison General electric Company and the Thomson-Houston Company, which themselves incorporated several other companies.
Electricity, technology, and lots of arcs and sparks!
Museum Of Electricity contains Vintage Electrical and Historical images and description. They include the Edison Lamp, Tesla Coils, Lightning and Atmospheric Electricity and the …..
Amazing Jacob’s Ladder
So how do they work? First two conductive metal rods are positioned in a rough “V” shape with a slight space between them at the base. A sufficient voltage differential is provided from a high voltage transformer to breakdown the air in the gap between the rods.
Here is a collection of web pages of VU Meter projects that helps a newbie getting into the Electronics DIY Hobby Land.
A Hobby now in your School days or College can help you build a strong profession later. It is Edutainment that will make productive use of your spare time. Friends can do it as a group, during holidays. Parents should encourage healthy hobbies, as the children will grow in a positive and creative atmosphere.
Stereo led level meter – This is it. It’s a STEREO LED LEVEL METER. It’s the cheapest and best bar graph display available and best of all, it uses readily available components.
VU-meter by Archy – Then it hit me. A VU meter, big, beautiful, professional! From that moment started my thoughts flowing. Those VU-meter ICs that are sold in every electronics shop?
LM3914 dot-bar display driver – The LM3914 is a monolithic integrated circuit that senses analog voltage levels and drives 10 LEDs, providing a linear analog display.
Knight Rider Display Project – This project started out as a VU meter. I reused parts and pieces to improve the VU meter and give it additional functionality. It is amazing how much time it takes to create a small thing like this.
Zelscope is a Windows software that converts your PC into a dual-trace storage oscilloscope and spectrum analyzer. It uses your computer’s sound card as analog-to-digital converter, presenting a real-time waveform or spectrum of the signal – which can be music, speech, or output from an electronic circuit.
Zelscope Sound card oscilloscope
Zelscope features the interface of a traditional oscilloscope, with conventional gain, offset, timebase, and trigger controls. As a real-time spectrum analyzer, Zelscope can display the amplitude and phase components of the spectrum.
The typical input voltage should be about 1 volt AC at the line-in jack of the sound card, so a voltage divider or a buffer amplifier is highly recommended.
xoscope for Linux – Similar Ptoject
Zelscope also allows for an easy measurement of short time intervals in mechanics experiments. Zelscope has proven useful in debugging music and sound processing software.
Hobby Electronics, Computing, Kits and Projects. Online version of Australia’s only electronics magazine, and is primarily directed to professionals, trades people and enthusiasts in the electronics, electrical, computer and related fields.
Silicon Chip Electronics Magazine
Projects to build do it yourself to save money, to learn new skills or simply for the fun of it!. Serviceman’s Notebook Actual cases, often unusual, from the bench of a full-time serviceman. Vintage Radio bringing back to life the discards of previous generations.
Each Silicon Chip design is carefully checked and tested and readers with the appropriate construction skills should be able to duplicate the design and have it work in the same or similar manner to the prototype.
40 Watts Hi-Fi Music System
Stereo Music player with Tuner, 1986, LED VU meter and Analog VU meter.
This was done as repairing home electronics was my hobby in school days, I learnt by building Amplifiers based only on transistors from the Old Philips Circuits and Books.
Home Made Circuits
The above one is TDA2020 20 Watts Per Channel, with LED input level meter and moving-coil output meters. It would have a 5 pin din input and RCA speaker output, input for phono, tape, etc. The Speakers had a woofer, tweeter and midrange with passive crossover network.
Stereo Adapter for Portable Music Player
Low Cost Stereo Adapter 20 Watts for Portable Music Player 1984, Bass Treble and Presence.
This was a TB810 based 10+10 Watts Stereo Amplifier with LM381 or 2 Preamplifier, The portable player docks in a wooden cabinet. There was no IR, Wi-Fi or Bluetooth in those days, so the device would interface with amp thru a stereo ear-phone socket-jack system with a shielded cable. Bass, treble and Presence as per an old phillps audio amp book.
Designing Bipolar Transistor Audio PreAmps, Designing JFET Transistor Audio PreAmps, Designing Op Amp IC Audio PreAmps, Switching Regulator Basics, Using Transistors As Switches.
RASON Projects Page – Amateur Radio
- 10 Amp, 13.8 Volt Power Supply
- 12 Volt Gel Cell Charger
- Thermal Fan Controller
- Transistor Audio Amplifiers
- 12 Volt Gel Cell Charger
- Switching Regulator Basics
A Potpourri of Audio Amplifiers By N1HFX
“I intentionally avoided the use of IC amplifiers to provide a real learning experience for audio amplifier design. Although many IC amplifiers provide excellent performance at low cost, we need to learn the basics first. I will address IC audio amplifiers in a future article.”
The Radio Amateur Society of Norwich
P.O. Box 329 – Norwich, Connecticut 06360