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Category Archives: Hobby Lab

Test Instruments and Small Tools for a Hobby Lab

Make a Shake LED Flashlight

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I  was enlightened about this Battery Less wonder. This is a boon for rural areas and an emergency tool which depend only on your will and your tendons. I found this bright flash of information when i was looking for supercap vendors.

Learn about Supercaps, dynamo and White LED

Richard J. Nelson on the LED Forever Flashlight. – The future of low power lighting is in the use of the Light Emitting Diode, LED. Sooner or later you will buy one or more LED lights or lamps. The two primary advantages of an LED light source is it’s efficient light generation (exceeding that of fluorescent lamps) and long life, typically 100,000 hours. That is 50 to 100 times more life than most of the bulbs in your house.

Learn about the Eternal Torchlight

This is a Linear Dynamo LED Torch which uses a SuperCapacitor to store the energy. Easy to repair and maintain if necessary.

It uses no batteries and requires only the single LED included. You can even leave the flashlight unused in your car’s glove box for years and you’ll always get that all-important light when you need it most. Forever Flashlight lll pays for itself quickly by saving you the cost of batteries and bulbs.

Electronics Tutorials – Ian Purdie VK2TIP

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Offering free comprehensive basic electronics tutorials in amplifiers, antennas, ham radio, filters, oscillators, power supply, receivers, test equipment, transmitters, radio design and electronics design. Links to data sheets and electronics reference and text books.

Electronics Tutorials – Ian Purdie VK2TIP

Amateur Radio, Amplifiers, Antennas, Basic Electronics, Ham Radio, Oscillators, Test Equipment.

Starting out you need to cover simple electronics which encompasses the topics of ohms law, voltage, current, resistance, capacitance, inductance, reactance, impedance and Q. Further topics in these electronics tutorials are power supply basics as well as digital basics.

Electronics Tutorials - Ian Purdie VK2TIP

What are voltage controlled oscillators

A voltage controlled oscillator or as more commonly known, a vco, is an oscillator where the principal variable or tuning element is a varactor diode.

Electrician Tool – Continuity Tester

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I had gone to buy some long wires at a electrician shop, when a terminal box had to be tested, he used a continuity tester.

When i used to buy electrical parts in the past, they used a tester box, made of wood. This had a bulb and a tubelight starter and two long wires (230v AC). The Continuity tester would light up a 40w lamp. Now he had a LED based one, so i got one for myself.

Electrician Tool - Continuity Tester

All it had, was two small cells in a plastic box with a LED, i was just flashing the LED as it looked nice thru the transparent box, it failed. The LED had burnt, the battery used. This product was not for monkeying around.

Now i performed a tiny design upgrade, I used a extra-bright 3mm Red LED with a 47 ohm resistor. Now it is robust, at least for continuity. The battery life can be good only if you make quick checks.

Improvements –

More protection may be needed to avoid damage to LED when this tester is applied across a battery by mistake. LED can flash to save battery power, one SMD – LM339 can be used for flashing and a more efficient short-leakage detector. A small oscillator with a neon may be more efficient and bright. This can also double up as a hidden Live wire or Mains AC detector.

Continuity Tester Circuit

A single chip metal detector with a range of a few inches. This is useful for detecting nails or screws in walls and floors, or for locating buried mains cable.

Continuity Tester

This article describes a simple continuity tester, based on an ATtiny85 and a piezo buzzer, designed for checking circuit wiring, or tracing out the tracks on a PCB:

Nuts and Volts DIY Magazine

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Online edition of US print magazine Nuts and Volts. Aimed at the electronics hobbyist, with articles covering amateur radio, cellular communications.

Nuts and Volts DIY Magazine

Nuts & Volts is written for the hands-on hobbyist, design engineer, technician, and experimenter. The diversity of subjects appeals to all levels of experience and spans such topics as amateur robotics, circuit design, lasers, computer control, home automation, microcontrollers, data acquisition, new technology, DIY projects, electronic theory, and more, not to mention the popular BASIC Stamp.

Adding More Digital I/O to your 16-Bit Experimenter Kit

16-Bit Experimenter Kit - Nuts and Volts

If you’ve been following the 16-Bit Micro Experimenter series in Nuts & Volts, you are already familiar with its solderless breadboard environment and the fully programmable 10 line I/O expansion bus that comes with the kit. The 10 lines can be assigned to be digital, analog or even connected to any of the PIC24F Microcontroller’s internal extensive peripheral set (i.e. dual UART, five CCP modules, ADC, Real time Clock Calendar, dual SPI, and dual I2C).

The Mini-Bench Supply

The Mini-Bench Supply

A small power supply with +5V, +12V, and -12V outputs is a handy thing to have around when you’re breadboarding circuits with both op-amps and digital ICs. You would want a switching regulator for efficiency, but linear regulators for low noise. Plus, it should be easy to build and relatively inexpensive.