Hobby Projects - Insulation tester, LED Circuits, Meters.
Showing posts with label LED-Circuits-Projects. Show all posts
Showing posts with label LED-Circuits-Projects. Show all posts

Monday, April 06, 2015

Energy Harvesting in Shoes for Small Devices

Walking is a Source of Energy that can be Harvested to Power LEDs or Wearables. It may one day Recharge your Smartphone or tablet. Just start running when the Battery goes low on your Phone. - Ananth

Here is the first page that will interest you - Parasitic Power Shoes Project

Energy Harvesting in Shoes for Small Devices

"environmental energy sources can begin to replace batteries in certain wearable subsystems. In this spirit, this effort has examined devices that can be built into a shoe, (where excess energy is readily harvested) and used for generating electrical power "parasitically" while walking."

Piezoelectric Energy Scavenging In Shoes 

Goal: To develop a rugged piezoelectric shoe insert and complementary conditioning electronics for unobtrusive, parasitic harvesting of the compression energy normally lost while walking

Wednesday, October 09, 2013

Battery Monitor for your Boat or Car

This is a colorful, useful and educative project from Erlich Industrial Development, Corp. You will learn using Op-Amps as comparators and also LED bar graph analog display.

Battery Monitor for your Boat or Car

Voltage Monitoring is an Electronics board that allows you to connect 5 to 14VDC on one side of the board and get it corresponding LEDs light on the other side. Every Car, tractor or boat should have one.

Battery Monitor for your Boat or Car

The boards will allow you to easily monitor your 12V battery while powering from the same battery. The Terminal Block TB connector is included and makes it easy to use.

delabs notes

The LM324 is the Heart or Intelligence in this Circuit. There is a voltage divider and zener too. They have a kit and pcb to buy and build .


A battery of a car can drive enormous amount of current, anything that is High-Voltage, High-Current or High-Frequency or a combination of these; are known to be high energy circuits. So as a precaution when you wire the positive to the car battery use an automobile fuse with holder like the one used outside the stereo player. The fuse has to be outside!

You could also use a fusible resistor in a metal box and keep it outside, the 12V positive has to go thru this. Any car/boat project needs this. A short circuit on PCB or Wire will blow fuse and everybody is safe.

Got it ..

Tuesday, November 20, 2012

Christmas Tree - CircuitStew

The true Christmas Spirit is in giving, You can only give if you have something, right. You can Have when you Acquire Skills, Imagination and a Cheerful Attitude.This will help you Create Things! 

Develop a Skill this Christmas, Build these small LED Trees and give it to people who need a little bit of cheering up.

Christmas Tree - CircuitStew

Christmas Tree - CircuitStew

"This was the first and last complete prototype that I made on proto board. This style of prototyping produces circuits that are very difficult to understand, debug, and modify. Because of all the extra work involved they also take forever to assemble. Suddenly I became very interested in designing and fabricating custom pcbs...."

The name CircuitStew refers both to the jumble of electronics presented here and to circuit boards suspended in neon green copper etching solution. -  Derek Wolfe

Thursday, March 15, 2012

Electronic Fifteen LED Roulette

The following was submitted on July 11th, 2007 at 12:47AM (PDT).

Message: I want to combine Ne555 with 74154 IC.The indication of the outputs must be shown with LED's but up to so far it need 15 outputs ,is it possible the way i did? if not i will need your assistance

Mail from CY

Electronic Roulette

See these circuits you will get an idea, Using CD4514 is also possible.


Tuesday, October 11, 2011

Toy SMPS or an Overkill White LED Driver

Jonathan Westhues site of Intriguing Projects include A Test Instrument for HF/LF RFID and a compiler that starts with a ladder diagram and generates native PIC16 or AVR code.

Toy SMPS or an Overkill White LED Driver

Toy SMPS or an Overkill White LED Driver

I sense the load current and control the duty cycle. The PWM pin on the AVR drives the gate of the FET through a couple of BJTs. Note the absence of any input capacitance; Vin looks terrible but it works. The micro power supply section is isolated with an RC.

delabs Notes

This is a nice way to start, learn uC and Power electronics in one go. It does not matter if it an expensive solution for LED Lighting. It certainly is an excellent Educational Project.

It may also be useful to use Intelligent Systems (uC and Firmware) to monitor and manage LED Arrays and control their brightness and color. Large Arrays can be Interfaced to PC by XBee for Home/Office or Factory Lighting Automation and Energy Consumption Optimization.

uC Real World Interface

uC I/O is Keyboard and LCD when you Build a calculator or a Text/Morse Communicator. When you control a motor it is Drive/Speed and Direction for Motor and Tacho or Opto Counters for Feedback. In both cases you have Input and Output which is Logic or Analog which has to reach the CPU.

Microcontroller Interfacing

Saturday, March 26, 2011

LM3914 - Versatile and Easy use Display

The LM3914 is a monolithic integrated circuit that senses analog voltage levels and drives 10 LEDs, providing a linear analog display. A single pin changes the display from a moving dot to a bar graph. Current drive to the LEDs is regulated and programmable, eliminating the need for resistors. This feature is one that allows operation of the whole system from less than 3V.

LM3914 - Versatile and Easy use Display
  • Drives LEDs, LCDs or vacuum fluorescents
  • Bar or dot display mode externally selectable by user
  • Expandable to displays of 100 steps
  • Internal voltage reference from 1.2V to 12V
  • Operates with single supply of less than 3V
  • LED driver outputs are current regulated, open-collectors
The circuit contains its own adjustable reference and accurate 10-step voltage divider. The low-bias-current input buffer accepts signals down to ground, or V-, yet needs no protection against inputs of 35V above or below ground. The buffer drives 10 individual comparators referenced to the precision divider. Indication non-linearity can thus be held typically to ½%, even over a wide temperature range.

My LM3914 Circuits

Millivolt Meter using a LM3914 LED Dot Display
Millivolt Meter using a LM3914 LED Dot Display
Circuits and Projects of LM3914

LM2941 Manual Fan Regulator & LM3914 Voltage Monitor - The LM3914 voltage monitor is also straight forward. As told I use only 6 of the 10 led outputs. A voltage divider on the input (R1-R2) decreases the 7-12V input to about 1.96-3.36V (x0.28). 

Novel white LED torch - LED bargraph readouts, here the LM3914 is used as the basis of a 10-step variable brightness current-regulated white LED torch!

Indikátor napětí autobaterie s LM3914 - This is actually a voltmeter that the size of the measured voltage signals using ten LEDs. The level of which will illuminate the first LED and the lights can be set to last.

Bauplan Schaltplan Bargraph Anzeige mit dem LM3914 - Analog displays have the undoubted advantage that you can get a reading very quickly perceives visually compared to digital displays.

Stereo Digital Camera Sync Shepherd - R7 sets the current through the LED's of the display. With R7 of 620 ohms, the illuminated display LED draws about 20 mA, which is about maximum for this display,

DIS*PLAYER: Theory and Construction -  This device drives ten LEDs in a linear display, with programmable endpoints and the choice of "dot" or "bar" modes of operation. Furthermore, it is possible to "chain" multiple devices for displays of virtually unlimited size. 

Monday, June 23, 2008

VU Meter Circuits and Projects

Here is a collection of web pages of VU Meter projects that helps a newbie getting into the Electronics DIY Hobby Land.

VU Meter Circuits and Projects

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.