The only electronic website that replies to every comment, and addresses all circuit related issues.

Cheapest SMPS Circuit Using MJE13005

The explained circuit in this article is probably the simplest and the cheapest, since it employs minimum number of components and the making of the circuit is very straightforward.

Transformerless UPS Circuit for Computers (CPU)

Normally when we talk about uninterruptible power supplies we imagine large inverter units with complex features, where it imperatively needs to be a pure sine wave type. Such inverters occupy enormous spaces, require bigger batteries and are immensely expensive. A little innovative thinking shows that the above cumbersome design can be replaced by just batteries and a small circuit for implementing all the necessary actions of an efficient compact transformerless UPS circuit.

Designing Circuits using Eagle CAD

Submitted by Mr.Judith 

Eagle CAD is a Professional PCB design package from the German company CadSoft. It offers an array of licenses, some of which allow individuals to use the package virtually free of charge. The learning curve may be a bit steep, but then Computer Aided Drafting is hardly simple, and most CAD packages have steep learning curves.

DC Double Cellphone Charger Circuit

A recent request from one of my followers Mr. Raja Gilse (via email), prompted me to design a DC double cellphone charger circuit that is able to facilitate charging of many cell phones simultaneously, let's learn how to make the circuit.

RF Signal Meter Circuit

 A neat little RF signal meter circuit has been discussed in this article which can be used to trace even the  minutest RF signals in the ether through an illuminated LED bar graph display. Courtesy: Steven Chiverton.

Very Low Frequency (VLF) Detector Circuit

Low frequencies predominantly cover our earth's atmosphere. This range of frequency may be created by many different sources which may be quite unknown and strange, a VLF sensor equipment can be made to trace these frequencies for investigating the intriguing secrets hidden behind it. Steven Chiverton investigates.

Making LED/LDR Opto Coupler Circuit - A Discussion

My good friend Mr. Chiverton shared his experience regarding the features of an LDR in comparison to  phto-transistors for making opto couplers. Let's learn what he discovered regarding opto couplers during his experience with my ghost detector circuit.

Ghost Detector Circuit Prototype Images

In one of my earlier posts, I discussed an intriguing ghost detector circuit which could be used for tracking or detecting paranormal activities or a ghost detector equipment. The system was sutably modified by one of the enthusiasts Mr.Steven Chiverton, Let's learn more regarding the procedures from Mr. Chiverton.

Inverted Relay Driver Stage Circuit

An inverted relay driver stage circuit design was requested to me by Mr Aparajit for some specific functioning of the relay, let's know the whole procedure of making the said circuit.

Discussing Advantages of Mosfets for Inverters

Please read the previous post for the continuation...

Hi Ali,

Although capacitors across the windings are not necessarily required, but your values are too small to cause a problem.

 Heatsinks are perfectly alright.

Discussing Adding a Capacitor at Inverter Outputs

Please read the previous post for the continuation...

Hi Ali,
The question is if the output stage is working with a square wave design, then why it's not working with my design? After all my design is also producing square waves.

Unless I see the prototype myself I won't be able to say anything.

Discussing Blown MOSFETs in an Inverter Circuit

Please read the previous post for continuation...

Hi Swagatam, I did what you said and it looks like IC2 is firing first, it blinks four times, then IC1 blinks four times. AH HA !
We're getting close !   What next ??

Improved IC4017 Inverter Circuit Discussed

Please read the previous post for continuation..

HI Swagatam, here is another schematic of a different modified square wave inverter using the same 4017 that your circuit is using. The main difference I notice with this one is there are NO diodes at the Output Pins of the 4017, where yours has diodes. Both circuits so far are both using Mosfets in the Output section. So I don't think the mosfets are the problem.
Let me know what you think.

Discussing a IC555 and IC4017 Inverter Circuit

Please read the previous post for continuation...

HI Swagatam, just updating you. I just double and triple checked my layout on the PCB against your schematic ,including the New modifications, and it's perfect.
Also one other observation, now  at the NEW Collector Junction Outputs of TR1 and TR2 there is + 8.40V.  Before the voltage at the Diode Junctions was only + 5.95V.
Its up to you brother.!! lol

Discussing Output Stage of a Square Wave Inverter Circuit

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Hi Swag,  I knew you'd figure it out !! What about the 10K resistors at the bases of the transistors, and the 1K resistors at the collectors. Keep those with the Transistors when I move them ,or get rid of them ?

Discussing Clock Signals for Inverter Circuit

Please read the previous post for continuation...

Hi Swagatam,  the 4069 square wave circuit I was using originally has 2 Clock signals . The first signal comes out of Pin# 2 of the 4069 goes to 10K resistor then to base of TR1. Part of that signal is diverted back into Pin# 3 and inverted  out through Pin# 4 and out the other resistor and to base of TR2. Please correct me if I'm wrong.

Inverter Circuit Using IC 4069, Discussed

Please read the previous post for the continuation...

Hi Aliman,
I am interested to follow the output stage exactly as given in your square wave design. I want you to include all the MOSFETs - NP as well as PN along with the buffer transistors and their base resistors.

Electronic Game Circuit Proposal - Unsolved

A request from another keen enthusiast and follower of this blog Sireesha dnv has been presented here, it's regarding the making of an electronic game circuit with some interesting functions. The ask looks a bit tough, especially with discrete components and without micro-controllers, let's learn the functioning details of the proposed circuit from the following email that was sent to me.

Battery Desulfator Circuit Explained

Sulphation in lead acid batteries is quite common and a big problem because the process completely hampers the efficiency of the battery. Charging a lead acid battery through PWM method is said to initiate desulfation, helping recover battery efficiency to some levels.

Make this Solar Powered Fence Charger Circuit

A Fence charger or energizer is an equipment which is used for charging(electrifying) a fence or a boundary in order to protect the inside premise from human or animal interventions. Since these boundaries are mostly of large fields and parks, are normally away from the main cities, and powering them through some renewable option becomes more suitable than from utility grids which may become difficult to acquire in such remote areas.

Make this EMF Pump Circuit and Go Ghost Hunting

EMF pumps are devices which are popularly used for the purpose of identifying paranormal activities or entities by generating rapidly rotating magnetic fluxes in the ether. The conventional devices use a spinning magnet fixed over a motor spindle, however these are mechanical types and are prone to wear and tear.

Load Independent/Output Corrected Inverter Circuit Discussed

The common problem with many low cost inverters is their incapability of adjusting the output voltage with respect to the load conditions. With such inverters the output voltage tends to increase with lower loads and falls with increasing loads. The circuit explained here can be added to any ordinary inverter for compensating its varying output voltage conditions in response to varying loads.

Make this Fastest Finger First Indicator Game Circuit

We all have probably seen the famous game show "who wants to be a millionaire" and many similar quiz shows, where in the initial stages a few of the participants are asked to go through a small test, the participants are asked a question, and the member who answers it first by pressing the buzzer is given the opportunity to occupy the "hot seat".

Make this Thermo-Touch Operated Switch Circuit Using IC 741

The circuit explained here employs a rather different approach for implementing a touch operated switch action. Here instead of the resistance, the warmth of the finger is used for sensing and operating the circuit's output.

Home Made100 watt MOSFET Power Amplifier Prototype Images

I had discussed one interesting 100 watt RMS mosfet amplifier circuit in one of my previous posts. The project was successfully completed by me, and I must say the results were amazing. Here are some of the pictures which shows the typical ingredients used while making the circuit.

Making an Adjustable Electromagnet Circuit

This article describes a simple circuit which can be used for pulsing an electromagnet. The IC 555 once again becomes the central part of the circuit. Let's learn the making procedure of this simple gadget for varying the magnetic power of an electromagnet.

Voltage Regulator IC LM1575 with Switched Output Explained

You will be amazed with the features offered by this outstanding voltage regulator IC. As the name refers to, the output from this series of ICs is not only regulated and stabilized but is in the form of switched pulses at very high frequencies. These ICs may be considered as an improved alternative for the conventional 78XX series regulators which tend to become hot with rising currents at their outputs, but not a problem with the series LM2575 from TEXAS INSTRUMENTS.

Make this Temperature Indicator Circuit with Sequential LED Display

In some of my earlier articles we have seen a few simple and interesting temperature indicator circuits. All these circuits are useful in some or the other ways, however these are not equipped with  step wise temperature level indicator arrangement and therefore tracking the varying levels of temperature cannot be identified using them.

How to Make a LED Flashlight Circuit

White LEDs have become so common nowadays that even school kids today know how to use them for making simple LED projects. LEDs are typically used for illuminating purposes, the discussed circuit is also intended for similar applications, that is as a flashlight.

Illuminating 24 White LEDs from two 9 Volt Cells

Nine volt cells as the rating suggest, provides 9 volt output, bvut what about the current? A 9 volt PP3 battery will not provide more than 400 mAH of current,meaning any load consuming 400 mAH would last for 1 hour, well that's with an ideal battery, normally it would last not more than 20 minutes, and the battery would get flat.

Make this Simplest Continuity Tester Circuit

A continuity tester is a device which is used for identifying the correct continuity of a particular conductor in question. Or in other words the device may be used for tracing faults or breaks in a particular conductor or a wire.

Make this Amplifier Power Meter Circuit

Music Amplifiers have always intrigued us due to their massive amplifying capabilities which completely changes the dimensions of the delivered music outputs. Fundamentally it's the power of the amplifier that's always on the scanner and we find folks getting too obsessed by the power rating of their procured amplifier unit.

Single Transistor Radio Receiver Circuit

This is probably the simplest radio that one could ever imagine of making. The circuit is so simple that it could be finished assembling within a few minutes and you are already listening your favorite programs over it.

Make this Electronic Mosquito Repeller Circuit

Mosquitoes can be considered as one of the most irritating bugs that not only trouble us a lot but have the potentials of spreading deadly diseases. These never seem to end, the more we find ways of eliminating them the more they come.

How to Make a 200 Watt Transformerless Inverter Circuit

Inverters as we know are devices which convert or rather invert a low voltage DC source to a high voltage AC output. The produced high voltage AC output is generally in the order of the local mains voltage levels. However the conversion process from a low voltage to high voltage invariably necessitates the inclusion of hefty and bulky transformers. Do we have an option to avoid these and make a transformerless inverter circuit?

Make this Simple Tachometer Circuit

A tachometer is a device which is used for measuring vehicle engine RPM. Thus, it is basically used for checking the performance of the engine and helps an auto mechanic to understand the condition of the engine so that it can be corrected or optimized as per the desired specs.

Simple Delay Timer Circuits Explained

In many electronic circuit applications a delay of a few seconds or minutes becomes a crucial requirement for ensuring correct operation of the circuit. Without the specified delay the circuit could malfunction or even get damaged.