Cool Stuff

Electronics Hobbyists say DoCircuits is the preferred Online Circuit Simulator.

Building Hardware was always cool. Physical things are great. Hardware companies like Apple, Aurduino, etc are disrupting our lives in a big way. At DoCircuits we love hardware hackers and are in absolute awe of their awesome design and applications they build.

Hobbyists use DoCircuits in various ways. Here are what some of the hobbyists tell us

“I have been using DoCircuits to understand some circuit in my amateur radio power amplifier. I was initialing confused about how some of the switching circuits functioned and modeled them until I better understood their operation. I found DoCircuits fairly easy to use an affordable, since I am in effect a hobbyist.”. DoCircuits User ( W9KB ).

“As a hobbyist I find DoCircuits very useful for entering designs and running the simulation. This is particularly useful when I am copying designs from others eg forums etc. It lets me put a design in, play with it and modify it before producing a physical board. I like the range of components and test equipment. I could never afford all of those tools!” – DoCircuits User ( pgalvin )

“So far I have been using DoCircuit for design of filter circuits. It replicates filter circuit outputs pretty accurately and the power analysis has been very handy, I would have blown some highly reactive circuits with large capacitance without it.”. DoCircuits User ( emklein )

Recently we starting tagging circuits based on the tag – “Hobby Electronics” and we urge our hobbyists and other users to use this tag ( To ensure you put a space between Hobby and electronics use double quotes – “ – when you try and tag ). Here are some circuits tagged with “Hobby Electronics” today.

You can search for circuits with this tag by clicking here –

Hobbyists can create some of these fun circuits and use our test and measurement virtual instruments to test and measure appropriate signals.

At DoCircuits – we have been listening to your feedback and we are working on features such as

  • Making simulation faster
  • Introducing more components
  • Better wiring capabilities
  • Better messaging for debugging
  • Private Sharing of Circuits

among other things. Please keep on giving us your valuable feedback and help us make DoCircuits the best Circuit Simulation tool for everyone

DoCircuits + VSKILLS : Become a Certified Electronics Design Associate Today !

The Indian Electronics Industry is going through a very exciting time. In last one year, the Government has announced a slew of policies to accelerate the domestic production of electronics goods ( ESDM policy 2013). Amongst the broad electronics market, certain segments that are expected to drive spectacular growth across the value chain are Smartphones, Set top boxes, LED lighting, Medical Devices and Tablets to name a few.   At the current rate of growth and development,the Indian ESDM industry could potentially employ 2.78 crore by 2020 compared to 44 lakh in 2010. This indicates an urgency to develop skilled manpower by creating the necessary institutions, providing infrastructure and encourage collaboration between industry and academia to hone skill sets. There is a strong need for standardized certification in Electronics to assess the skill of candidates.

At DoCircuits we believe that our experience,expertise and solutions can address this. We are excited to announce that we have teamed up with VSKILLS (, a Govt of India initiative, to certify and assess candidates for a Certified Electronics Design Associate certification.   This certification will help candidates secure the right jobs in Electronics, do the right career moves, and get a notch above their peers. According to Jasneet Singh – CEO of VSKILLS, “There is a dire need for harmonized effort to reduce the employability gap and address the structural issues of job demand in the new age sectors – a collaborative approach by government, industry and corporate is therefore required to bridge the skill gap and increase productivity and output.”

The process for this is very simple. As a first step – you need to sign up for the certification and pay, as a second step – the preparatory material comprising of E-books, virtual lab access through DoCircuits ( , mock tests are sent to you and you get to choose your certification venue,date and time. Once you are ready, you take the certification exam and on completion, you get a joint certificate from VSKILLS and DoCircuits. There are other exciting benefits like getting a VSKILLS brand on your resume at MonsterIndia and placement assistance from VSKILLS on successful certification. You can find more details at –  

We strongly believe that certifications such asCEDA will open opportunities for the right candidates in the ESDM industry.

DoCircuits Experiential

It is exciting times at DoCircuits.

We are working on launching  ”DoCircuits- Experiential” a hands on online course with labs in Circuits in early 2014. We believe learning electronics and circuits could be much more fun, practical oriented and more hands on than what it is today. And so we are working on DoCircuits – Experiential, the coolest course which teaches you to learn Electronics Circuits by building projects and combines online video tutorials, virtual labs and hands on labs using real components and a state of the art USB based oscilloscope, waveform generator, etc. 

To do this, we are raising funds on Indiegogo to help us design and deploy the course. We wanted to share this launch exclusively with you at

To be successful at this, we are counting on your help. You can help us in following ways. Please help us by :
1. Your contribution. Your contribution anywhere from $10 to $300 will help us spread the word and build momentum for this. Click on the link (  ) and contribute.
2. Help us spread the word. Share about DoCircuits-Experiential on Facebook, Google Circle or Tweet about it. You can just share the link above and say – “This seems like the coolest way to Learn Electronics.”
3. Forward this to your friends and get them interested in our project.We look forward to your support.
Please feel free to reach us at in case of any questions.

CircuitJam : Your monthly newsletter from DoCircuits – Sep, 2013

DoCircuits: is going places and so are you. We are still reeling from the awesome response we got for CircuitTrek 2013 – the first ever online circuit design competition. More than 100+ teams registered and played out doing circuits for 2 weeks – 2 weeks of intense team work, competition and innovation. We will soon launch the next version of CircuitTrek – watch this space.

We were working at some cool enhancements while you were using DoCircuits. You would have noticed our new features such as - Real and Symbolic ViewsFile based sources7 Segment Display , Multiplier IC, Digital ICs, New component dashboard, etc. I hope you are enjoying using them as much as we are enjoying making them !

One of the important features introduced is a more affordable DoCircuits plan to you users ( All PRO users will automatically get migrated to GEEK licenses ). We urge you to check out the new pricing plans and opt for a more affordable DoCircuits. Your support will help us to continue our effort on innovation and building cool features in DoCircuits. For those who want to earn rewards, we are running a ‘Refer a friend Campaign‘ all of this month. Invite your friends and get complimentary HACKER licenses – yes, I know that’s unbelievable, but its true !

Join us on facebook on more recent updates, fun and engaging contests. Until then have fun with your circuits ! If you have any feedback drop us a line at 

A 7 segment display !

Hi folks! We have been working a lot here at DoCircuits and have come up with some more cool components. Recently we have added a BCD to seven-segment decoder along with a seven segment LED display. You can build really nice experiments with these new additions.

Here is one such interesting circuit: ( Click here to load and run the circuit )

7 segment display

7 segment display

What does this circuit do? It’s a simple counter display that displays the values counted from 0 to 9. This has many interesting applications. One such application is as a token display in banks and hospitals which will display which token is present at the counter and a simple push of a button the next number is displayed.

For this circuit a 7447 IC is essential. This IC is a decoder which converts the BCD input to its corresponding seven-segment code. This code is used to light up the corresponding LEDs in the display so that the BCD number is displayed in decimal. The input of the decoder is given by a simple MOD 10 counter (in real life such ICs like 7490 are used for BCD counting and yes, we’ll be adding it soon too).

It’s that simple. The counter counts from 0 to 9 and the corresponding number is displayed.

ScopeWar : Tektronix Vs Agilent Vs Rigol

We all know how important oscilloscopes are. They are used for analyzing and measuring wide range of electrical signals. Because of their higher precision and data storage capabilities digital storage oscilloscopes are used extensively. These scopes are used in field engineering, research and development, technical education, electronics and electrical system analysis and debugging. Current trends in microprocessor and digital signal processors technologies allowed these devices to crunch large amount of data, they are also pushing speed barrier to the extremes. Scopes are becoming smarter and smarter because of multi-core designs.

Entry level oscilloscopes christened the 1000 series oscilloscopes are good powerful oscilloscopes at affordable prices. These oscilloscopes are targeted to cater to the needs of technical education market segment. Priced in the range of $400 to $800, several major manufacturers have introduced their scopes for this segment. They have simplified user interface, which makes it easier to learn how to use them.



Rigol DS Oscilloscope

Tektronix introduced their TBS1000 series oscilloscopes in late 2012. In the same year, Agilent introduced its DSO1000 series oscilloscope. Two years earlier, Rigol launched its version – the DS1000E series.[3][4][5] Let us consider the models which have a bandwidth of 100 MHz and two channels, and do a comparison. So, we will look at Agilent – DSO1102B, Rigol – DS1102E and Tektronix – TBS1102 models. How digital scopes work is beyond the scope of the current discussion and this can be addressed in a separate article if need be.

Tektronix TBS Oscilloscope

( You can virtually experience the TEKTRONIX TBS Scope at - )

The key parameters to be seen while comparing oscilloscopes are: number of channels, bandwidth, sampling frequency, memory depth, triggering, rise time and cost. Let us understand these parameters one by one.

Agilent Digital Oscilloscope

Sampling frequency

The rate at which an analog signal is sampled is called the sample frequency, the number of samples per second. If the sample frequency is higher it means that interval between two samples is shorter. Higher sample frequency allows the original signal can be reconstructed much better from the digital samples.

Memory Depth

For any given sampling frequency number of samples acquired determines the record length or memory depth. For example, if your scope specification says that it’s memory depth is 2.5k points and it acquires samples at 1GS/s then is calculated as mentioned below.[6]

Measurement duration = Memory depth / Sampling frequency

= 2.5k/1G = 2.5 usec

Memory depth is always proportional to sample frequency. So, deeper the memory, higher will be the sample rate. Higher sample rate increases the scope’s bandwidth. This is both an advantage as well as disadvantage. Having a sufficiently large memory allows you to measure the signal for higher duration in one go. However, having a higher memory depth points will make scope slow.


The trigger determines when the oscilloscope starts to acquire data and to display a waveform. When a trigger is set up properly, the oscilloscope converts unstable displays or blank screens into meaningful waveforms.[3]

Typically, edge, pulse, video and alternate trigger types are provided by most of the vendors.

Edge trigger can be used Can be used with analog and digital circuits. An edge trigger occurs when the trigger input passes through a specified voltage level with the specified slope. Pulse trigger is used to find pulses with certain widths. Video trigger is used to trigger on fields or lines for standard video waveforms. Alternate trigger is used to trigger on non- synchronized signals.[1][2][3]


Automatic measurements

DSO vendors offer automatic voltage and time measurements on channel data;

Voltage measurements include maximum voltage, minimum voltage, arithmetic mean, peak-to-peak voltage, peak voltage, true RMS voltage, overshoot and preshoot.

Time measurements include frequency, period, rise time, fall time, positive width, negative width, duty cycle so on and so forth.[3][4][5]


USB device interface allows you to connect DSO to a desktop computer to upgrade on board firmware. This interface also allows you to connect DSO to a PictBridge compliant printer to print screen image directly. USB device interface provides another very useful feature of controlling DSO remotely by sending appropriate commands over the network.

USB host port allows you to take a copy of acquired data on to a USB mass storage device in a file format.[3][4][5]

Miscellaneous Features

Other miscellaneous features provided are math operations such as addition, subtraction, multiplication and FFT on channels, simultaneous view of main and zoomed waveforms. Most of the vendors provide digital filters namely; LPF, HPF, BPF and BRF.


You can buy one of these directly from respective vendors, or you can also try element14 or RS component. The pricing remains the same even if you buy from distributors

Here is a comparison across various important specs;

Specification Agilent – DSO1102B Rigol – DS1102E Tektronix – TBS1102
Bandwidth 100 MHz 100 MHz 100 MHz
Sampling 1GS/s – 1 channel on500MS/s – 2 channels on 1GS/s – 1 channel on500MS/s – 2 channels on 1GS/s – 1 channel on500MS/s – 2 channels on
Memory Depth 16kpoints – 1 channel on8kpoints – 2 channels on 16kpoints – 1 channel on8kpoints – 2 channels on 2.5kpoints – 1 channel on1.25kpoints – 2 channels on
Trigger Modes Edge, pulse width, video, and alternate Edge, Pulse Width, Slope, Video, Alternate Edge, Video, and Pulse Width
Automatic Measurements 22 voltage and time measurements and cursor measurement 22 voltage and time measurements and cursor measurement 16 voltage and time measurements and cursor measurements
Connectivity USB device and host USB device and host, RS232 USB device and host
Cost 1100 USD 399 USD 1100 USD


Conclusive Remarks

Every DSO model is designed keeping certain applications or use-case scenarios in mind. You should choose a model which suits your application. Don’t get biased by the numbers, because bigger is not always better. So, be smart and choose your scope wisely.


For more information, visit the following links;

You can also visit the following link to virtually experience TBS1102





File Based Sources : Now do your own thing !

Using DoCircuits, you can generate a sine wave, square wave, pulse wave, triangular wave among others. But what if we can push the limits? What if we have near-infinite choices to the types of the wave that can be generated? Well, say hello to the piece-wise linear source. Don’t be intimidated by the name – it’s no big deal. A piece-wise linear function is a function that is defined by sub-functions where each of the sub-function is defined individually for a minute period of time.

Simply put, one can generate the function of one’s wish using this source, by defining what the amplitude of the function is supposed to be and for what time. In addition to that you can also define whether the signal is supposed to be periodic or not. So using this piece-wise linear source you can generate any signal of your choice.

So how is it possible? It works similar to the other sources. You can start by dragging and dropping a piece-wise linear source.

Linear Source

In the field provided you have to enter the values that the function should take and the corresponding time. For instance, let us say we give a set of data as follows: 0,0;0.05m,1;0.1m,0;0.2m,3;0.3m,0. In words it means the first point is 0 s, 0 V followed by 0.05 ms, 1 V; 0.1 ms, 0 V and so on. The first value is the time domain and the second value separated by a comma is the voltage domain. Note each point is distinguished from the next point by a semi-colon. Finally after you simulate, all these points are linearly connected to give you the function that you wanted.

Here are some different signals that I generated and plotted:

Linear source plot


So go ahead folks! Try your hand at different types of sources for your experiments. Who knows, there could even be an artist hidden in you, and it may be revealed in how you create awesome plots! As an example, checkout the following circuit – A rectifier using a Piecewise Linear Source. Click on the circuit to run the experiment.


Online Learning and Its impact on Technology

I was watching this incredible video by Daphne Kolher as part of a TEDx talk. For the uninitiated Daphne Koller is enticing top universities to put their most intriguing courses online for free — not just as a service, but as a way to research how people learn. With Coursera (cofounded by Andrew Ng), each keystroke, quiz, peer-to-peer discussion and self-graded assignment builds an unprecedented pool of data on how knowledge is processed. With Coursera, Daphne Koller and co-founder Andrew Ng are bringing courses from top colleges online, free, for anyone who wants to take them.

What was interesting observation to me is with a slew of online courses in technical education done mostly using video lectures, quizzes ( objective ) may not be sufficient enough for students to achieve all the required learning outcomes. For example, a lot of courses needs labs for doing hands-on experiments – like EE courses, or needs students to acquire cognitive skills like being able to design, apply, evaluate, etc. Soem courses may need the students to do projects. How do you grade and assess such skills in an online framework ? Clearly quizzes are only a tip of the iceberg. Are the learning outcomes being sufficiently addressed in such courses ? What are your views ?