The Number of Buttons on the Touchpad
When using notebook PC, the most troublesome is the number keys, I believe many people have the same feeling, so the market has also been an external numeric keypad to facilitate.Chinese Nanjing...
View Article9V FM Transmitter
This fm transmitter circuit is a very simple and require few external components and operates in FM band above 100 MHz.This fm transmitter needs to be powered from a 9 volts battery or from another 9...
View ArticleDigital Clock with Timer and Solar Panel Regulator
This is a combination digital clock timer and solar panel charge controller used to maintain a deep cycle battery from a solar panel. The timer output is used to control a 12 volt load for a 32 minute...
View Article18 Stage LED Sequencer Circuit
Description The question sometimes comes up of how to cascade 4017 decade counters for more than 10 sequencial stages. The LED sequencer below shows a possible solution using a few extra parts. When...
View ArticleThe Nite Rider Lights Circuits Diagram
As a keen cyclist I am always looking for ways to be seen at night. I wanted something that was a novelty and would catch the motorists eye. So looking around at my fellow cyclists rear lights, I came...
View ArticleSimple DC to AC Inverter Circuit Diagram
Simple DC to AC Inverter Circuit Diagram This DC to AC inverter circuit work based on unstable multi vibrator does. In this circuit, IC CD4047 is chosen as a heart of unstable multivibrator, because...
View Article1991 Mazda B2600i Wiring Diagram
1991 Mazda B2600i Wiring Diagram(click for full size image)The Part of 1991 Mazda B2600i Wiring Diagram : battery, main fuse, main boa, btn, cruise control unit, carburetor, feed back carburetor,...
View Article22W Stereo Amplifier Using TDA1554
Here is the 22 watt stereo audio power amplifier circuit diagram based on TDA1554 and integrated circuit from NXP semiconductors (formerly PHILIPS semiconductors). It is very simple and useful circuit...
View ArticleRC Remote Control Switch
It is sometimes necessary for an RC (remote control) model to contain some kind of switching functionality. Some things that come to mind are lights on a model boat, or the folding away of the...
View ArticleLED Volt Meter
Here is a Simple LED Volt meter to Monitor the charge level in Lead Acid Battery or Tubular battery. The terminal voltage of the battery is indicated through a four level LED indicators. The nominal...
View ArticleTransformerless Power Supply Circuit
This circuit will supply up to about 20ma at 12 volts. It uses capacitive reactance instead of resistance; and it doesnt generate very much heat.The circuit draws about 30ma AC. Always use a fuse...
View ArticleInteractive Toy Traffic Lights
This toy traffic signal uses a single low-cost hex Schmitt-trigger inverter IC (IC1a-IC1f) to directly drive three coloured LEDs (red, green and amber). At switch-on, the circuit lights the red signal...
View ArticleUsing AC for LED Christmas Lights
This circuit uses low-voltage AC to drive a string of 50 or so bi-color LEDs (two LEDs connected in inverse parallel). Power to the LEDs is controlled by the Triac and the two optocouplers which have...
View Article10 000x With One Transistor
For a collector follower with emitter resistor, you’ll often find that the gain per stage is no more than 10 to 50 times. The gain increases when the emitter resistor is omitted. Unfortunately, the...
View ArticleVery Simple Bench Amplifier
A small 325mW amplifier with a voltage gain of 200 that can be used as a bench amplifier, signal tracer or used to amplify the output from personal radios, etc. The circuit is based on the National...
View ArticleLinear RF Power Meter Circuit
The National Semiconductor LMV225 is a linear RF power meter IC in an SMD package. It can be used over the frequency range of 450 MHz to 2000 MHz and requires only four external components. The input...
View ArticleAutomatic White LED Garden Light
This white-LED driver circuit is ideal for use in a garden light. It automatically turns the LED on at night and runs from a single 1.2V nicad cell which is recharged by a solar cell during the day....
View ArticleActive Short Wave Antenna
The circuit presented here illustrates the fact that in spite of all kinds of new component and technology, it is still possible to design useful, and interesting, circuits. The circuit is based on two...
View ArticleSolar Panel Voltage Regulator
Our energy-hungry and environmentally aware society has been slow to make good use of the suns "free" power. But now its finally taking off. Using the suns heat directly, for cooking and other...
View ArticleA Stereo FM Transmitter BA1404
Youll find that this is a very easy project to build. It will transmit good quality sound in the FM band ( 88 - 108 mhz ). One important item is that the IC chip operates on 3 volts DC. The chip will...
View ArticleRelay Toggle Circuit Using a 555 Timer
This 555 timer circuit below toggles a relay when a button is pressed. Pins 2 and 6, the threshold and trigger inputs, are held at 1/2 the supply voltage by the two 10K resistors. When the output is...
View ArticleCar Battery Saver
Prevents the complete discharge of the battery when the door is left open accidentallyI recently forgot to close the door of my car after parking in the garage and I found the battery completely...
View ArticleDC Coupled Audio Amplifier
Designs for audio amplifiers with DC coupling to the load are not often encountered these days, even though they offer definite advantages. One advantage is that there is no need for the complication...
View Article4 Minute Shower Timer
Gone are the days when we can afford to luxuriate under a hot shower for hours on end. Well, maybe the showers weren’t quite that long but most people are used to taking showers in the tens of minutes....
View ArticleMarlec 12 24 Volt Inverters Explained
What is an Inverter and why would I want one?An Inverter is a device that takes the power from your 12 Volt or 24 Volt DC battery and converts it to 230 Volt AC power to run your normal household...
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