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Why Top-notch Secured Memory Chips are Essential for Video Surveillance Cameras?

For the past few years, video surveillance cameras have become an important part of our life whether in a business center or in our homes. Inside these cameras, the memory chip is a very important part of the technology that helps us to view what the cameras witnessed and recorded. The videos and the images that are captured sometimes prove to be very critical and hence, it is imperative to ensure that the images captured are crystal-clear. Moreover, the images and the videos captured are also used for the purpose of proving someone’s crime and these devices are subject to cyberattacks. Therefore, it is essential to have the cameras and the memory chips cutting-edge and secured. Various experts have now highlighted the importance of data security in the video surveillance domain, the importance of secured memory chips, and the key requirements to boost the sector. Nowadays, protecting communities, businesses, and homes from external threats has turned out to be an urgent need of the hour for many.  Hence, the Security Products Group in India wanted to undertake a study on the key security products which comprise CCTV Camera Systems, Recorders (DVR/NVR) & Access Control Systems. The aim is to target a 20-25% percent share of the global market of USD 60 Bn by 2025.

As there is so much dependence on the surveillance system, there can be a serious threat of data loss in case of system failure or some external hacking. Commercial and residential utilization of security cameras needs the recordings to be well-documented and completely secure so that information cannot be lost easily. The Feedback Advisory report recently mentioned that the global Surveillance & Access Control market size was ~USD 43 billion in 2021 and is projected to reach ~USD 66-67 billion by 2026, exhibiting a CAGR of 8.9% during the forecast period.

Indian Surveillance Industry Graphs and Charts

Source: Feedback Advisory

In order to boost the video surveillance sector in India, recently an MoU has been signed between Sahasra Group of Industries and Samriddhi Automation (Sparsh) where the former would manufacture top-notch secured memory chips for Sparsh’s video surveillance cameras, which are completely Made-in-India. Amrit Manwani, Managing Director at Sahasra Group of Industries said, “This is the first time when two Indian SMEs have come together to boost the Make-in-India initiative. We will design and manufacture both the chips and cameras completely in India. Apart from that, we are also looking forward to manufacturing the camera components in India through our semiconductor operation. This is how we can reduce our dependence on imported supply chains heavily. By the time both the phases of investments are completed, we will have a capacity of 18 million chips per year and out of that production, 20 percent will be given to Sparsh.”

The industry association also stated that the security of data has turned out to be very important these days. The entire world is now facing this same problem and in the video surveillance domain, developed countries like the US and the UK are facing data security threats. The technologies they are having is not enough to identify where their data is moving and to which country. In fact, both the US and the UK had banned leading chinese companies from operating including the latest one is the ban of Huawei.

Highlighting the importance of data security, Sanjeev Sehgal, MD at Samriddhi Automation said that the current technologies are not enough to help the countries identify whether the data is moving out of their country or not. Hence, it is now important to manufacture the chips in India. Data has to go to the memory and therefore, the memory chips have to be fully secured. Nowadays, data needs to be stored in the memory for quite a long time and this is because the apex court of India has unleashed a new ruling that all police stations, jails, and investigation centers must be furnished with CCTV cameras where the videos have to be stored for at least eighteen months. 

Going further, experts of various industry associations such as ELCINA stated that the current value chain for the video surveillance market in India is crafted out of a variety of stakeholders who are playing a different role. The Domestic supply of CCTV Products has risen to 80% of the total supply in India in FY 2021-22 from 52% in 2017-18. And over the coming five years, the market is expected to grow at 15-17% CAGR.

Video Surveillance Industry Growth Graphs

Source: Feedback Advisory

Cdr Mukesh Saini (Retd.), VP- ExeStat, Senior Advisor- Cybersecurity & Privacy- Amtrak, Lab systems & iRisk Assurance said, “Nowadays, in every institution, 50 percent of the time is devoted to security aspects. Ten years back, it was very difficult to understand the problems and challenges of this domain. The memory chips and the hardware equipment associated with surveillance cameras has to be cutting-edge or else there will be a huge possibility of video leakage. But combining them with AI technology, it will be easy to identify where the data is moving and also tracking some critical person across the country, which is now becoming very sensitive. The CCTV footage has to be secured forensically. You need to walk on those fields, develop, so that the output that is put on the storage does not get spoiled. Even one pixel change is a big change because in that case, it could erase evidence completely. A reliable storage system for the CCTVs is necessary so that evidence can be taken to the court seamlessly.”

Speaking of the challenges of the sector, experts stated that there is a lack of a clear component ecosystem and a proper definition of local content- value addition. Moreover, Makin in India needs to be competitive with the world, which they are not currently. Also, there is a lack of design led manufacturing in the country for such a critical security related product. In order to get rid of the challenges, ELCINA recommended that there should be identification of components required for the video surveillance systems and classify them accordingly. There are components available in India, but industries are facing problems. In that scenario, ELCINA recommended to act as an aggregator of the demand and get vendors of such components and conduct buyer and seller meetings.

Speaking further on security challenges associated with the sector, Samrendra Mohan Kumar, Founder & MD, MitKat Advisory told, “Cybersecurity damages in 2021 is already 6 trillion dollars and the physical and environmental security damages were all one tenth of this total. China targeted seven leading semiconductor vendors in Taiwan and their goal was to steal IPs, documents, source, and the software development kits. The attackers used open source general tools along with a rarely key skeleton technique. Due to this scenario, the VPNs of the vendor’s systems were compromised. The tools made adversaries login like normal users. There are only two types of systems; one who is compromised and knows they have been compromised and the other who have been compromised and they do not know about it.”

For the components, which can be developed in the India category, many companies have already started the localization of products and have developed vendors for the products such as housing, cables, packaging products, screws, nuts etc. Now, speaking on the components that are not available in India, the Government needs to make special investment pitches to attract International firms to India with special policies for these components and they should work towards attracting a minimum of 2 Units in India in Lens and SOC Chipsets fabrication. Last but not the least, ELCINA requested that for SOC Chipsets, the Government of India could think of linking this to the India Semiconductor Policy and get these SOC Chipsets to be included as a ‘preferential products’ to be made in India with the ATMP/OSAT Projects. Unlike Finished Goods/EMS operations, component manufacturing has a very high “Investment to Turnover ratio” and needs a much longer gestation period for the payback. These special considerations need to be factored in these policies, suggested by ELCINA.

Experts also suggested that there should be efforts made to encourage all manufacturers to undertake a Design Led Manufacturing business in the country with the overall product design IP being developed and available in India.This could be definitely implemented in the volume business of B2C cameras/DVRs and NVRs and not for the high-end projects business cameras and NVRs. Also, it needs to be highlighted that PCB, firmware, silicon on the chipset, software, integration between cameras and storage server, everything should be fully developed in India. The industry leaders also urged for R&D centers to be available in India, only then Made in India certification must be provided.

Now, it is very important to invite the global investors to come and invest in the Indian business ecosystem. But, at the same time, there are instances of long-standing Indian companies who have been investing in this business who need to be treated on par and not ignored in some policy initiatives. For example, linking investment as an eligibility criterion in the PLI scheme could be done away with firms who have already invested in the past and the investment needs to be recognized. In order to address the lack of information on vendors for the CCTV products industry, there was a request for the government to come up with a component portal that could be updated on a real time basis for all firms setting up components units in India and as soon as the unit is operational the details of such firms are updated on a real time basis

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Simple DIY FM Receiver Circuits on the Internet - Do they Really Work?

Recently we thought of building a simple FM receiver circuit, so like always we started googling for possible circuits that can be used to fulfill our requirements, and as expected we found a lot of circuits on the internet, but the question remains how good or useful will they be when we put those circuits to the test. Because just like us we found a lot of people trying to get these circuits to work but fail, and a lot of discussion forums are filled with questions "Do these simple DIY FM Receiver circuits really work?"

So in this tutorial, we did just that by building a few circuits on a piece of perf board and testing each circuit to see their working and what can be done to improve this, and in the end, we will let you know all the details. 

Now if you want to save time, you can straight away buy the RDA5807 FM receiver module and use it for your project, we have already built a  Voice Controlled FM Radio using Arduino and Google Assistant and Arduino Based FM Radio using RDA5807. You can check those projects out if you want to learn more about those projects or you can check the simple FM transmitter circuit built using basic electronic components like transistors, capacitors, coil etc.

The Two Transistor FM Radio or the Direct (TRF) FM Receiver

Most of the circuits we have found on the internet have one thing in common, and that is they all have a two-transistor configuration. And for our first circuit, we tried something similar.

FM Receiver Circuit Diagram

Not only it receives the FM signal it also amplifies the received signal with the help of an lm386 OP-Amp IC to drive a speaker. This is by far one of the most complicated circuits made with very few components. The transistors BF495(T2) with Inductor L. Capacitor VC, and along with T1 makes the construction for the Colpitts oscillator.

In this circuit, the trimmer VC sets the resonance frequency of the circuit. By adjusting the variable capacitor the resonance frequency changes and we can tune the circuit anywhere between 88 and 108MHz. The message signal that is received through the circuit is extracted through the resistor R1 and then it is fed to the audio amplifier over a 220nF coupling capacitor (C1). This circuit is so designed that you can tune the radio receiver with the help of the Variable Capacitor. The value of the variable capacitor is adjusted to 20pF because variable capacitors with this value are readily available.

The coil used in the circuit is a simple air core inductor made with 4 turns of 22 SWG copper wire with the core having a 4mm internal diameter. When the required number of turns is reached the coil is cylindrical. The coil can be taken so that the high frequency signal can be reached by the receiver. Finally, the capacitors C3 (100nF) and C10 (100µF, 25V), together with R3 (1k), comprise a band-pass filter for very low frequencies, which is used to separate the low-frequency signal from the high-frequency signal in the receiver.

FM Radio Receiver with 2N3904 Transistors

Next, this is another FM radio receiver circuit that has a two-transistor configuration. But like the previous circuit, this circuit uses two 2N3904 general-purpose transistors to generate the resonance frequency

FM Receiver Circuit Diagram

While testing the above circuit we have observed that this circuit works best between 3.3 to 3.5 Volt range. The working of this circuit is very simple, the resonance frequency of the circuit is generated by the L1 and C1 in the circuit, LC together is called a tank circuit that is able to produce high frequency oscillation that is required to generate FM signal, when the capacitor gets fully charged then it dumps it to the inductor, the inductor charges up and builds up its magnetic field when the magnetic field collapses the energy gets back to the capacitor and the process repeats infinitely the resonance frequency of the circuit can be easily found out by using a simple formula. In the next section, we will be looking at that 

Building an Inductor and Calculating the inductance

The most important part of any FM radio circuit board is the inductor and in this section, we will learn how to build an inductor. If you look at the first circuit, it says it's 4 turns in a 4mm diameter air core with 22 AWG copper wire. Once we have built the inductor we can use the formula shown below to calculate the inductance.

L= (d^2 * n^2)/(18d+40l)

Where,

L=  is inductance in microHenries (µH)

d= coil diameter in inches

l= is coil length in inches

N = Number of turns

Now as we know the formula, we need to measure the diameter of the coil to calculate the inductance. If you look at the first schematic you can see that the instruction to make the inductor is given. Its 4 turns of 22 SWG wire with a 4mm diameter air core. For the 4mm diameter, we are using a refill from a gel pen. As you can see from the image below the refill from the pen is exactly 4mm.

calculating inductor inductance

Now once we have the 4mm diameter cylindrical, we will wrap our 22 SWG wire around the pen refill and make the inductor. Once the inductor was made it looks like the image shown below,

calculating coil inductor inductance

Now we will measure the length and the diameter of the coil and as you can see from the image above we have a coil diameter of 6mm and the length of the coil is 3.2mm. With this, we have all the parameters to calculate the inductance of the coil.  Now if we calculate the inductance by using the formula given we can calculate the value is

L = 0.0961 uH

You can do the calculation by putting the values in the calculator or you can use the Air Core Inductor Coil Inductance Calculator website to calculate the inductance which makes the process so much easier.

Testing FM Radio Receiver Circuit Board

As you can see from the above two schematics we have found two promising circuits on the internet and we tried to test both circuits, the circuit made with BF494 transistors performed somewhat better than the circuit made with 2N3904 transistors. You can also see that we have made the two circuits in two different places because we don't want to add in noise from any other components.

FM Radio Receiver Circuit Board

As you can see the test setup shown in the above image where we are powering the circuit with a 12V battery. Once the circuit was powered on we turned the variable capacitor to try to tune the circuit to capture local FM radio stations, but the circuit wasn't able to pick up anything.

After checking and trying to figure out what the problem was we used a Raspberry PI to build a FM transmitter and check to see if the circuit was working or not. And to our surprise, the circuit worked but the audio was not audible and the sound. 

In conclusion, we can say that it's absolutely not worth it to waste time on building and testing this kind of simple FM radio receiver circuit because it's not made to be used for day to day application. And it's recommended to use a proper IC based FM radio receiver module if you intend to use this for day to day application. If you are looking for some FM Radio Receiver IC Then the RDA5807 or TEA5767 are some of the ICs which are easily available in the market and you can make simple FM receiver circuit with easily available parts and schematics.

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"India is the under-rated manufacturing hub of the world with more than 50,000 suppliers capable of catering to the automotive industry alone" - Dheeraj Tiwari, Co-founder and CEO of CapGrid

During the first half of 2020, when the pandemic was creating mayhem throughout the world, the automotive industry faced the worst challenges whose production was halted to a larger extent. The industry was the residue of several disruptions such as electric mobility, and ridesharing, and also deprived of its financial growth. The increasing competition in this sector mostly in manufacturing has paved the way to overcapacity, which is now viewed as one of the serious challenges by the experts.

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Staff Mon, 12/05/2022 - 16:53
India must not go by the Volume of Defense and Homeland Security Products, but by Quality; Defines Experts

Of late, a report of a well-known media stated that India's Electronic Security Market was valued at USD 1.32 billion in 2021 and is expected to reach USD 4.90 billion by 2027, at a CAGR of 24.37 percent over the forecast period. The homeland and defense security sector has tremendous potential and since then the growth of security products has changed and now, the country has several manufacturers from the security electronics domain.

Nijhum Rudra Mon, 12/05/2022 - 12:49

Sahasra Group Plans to Invest Rs 800- Rs 1000 Crore in Electronics Manufacturing in the Coming Four Years

Q. What are your views on the current electronics and semiconductor manufacturing ecosystem in India? Where do you think India currently stands at this time when compared to other developed countries?

How India Can Become Self-Reliant and Globally Competitive in Electronics Manufacturing

With the assistance from the government of India in unleashing Rs 2.35 Lakh Crore policy push, the home-grown electronics manufacturing cluster is expected to witness a healthy 30 percent growth in the coming financial year, which is around Rs 7 Lakh Crore. Experts in the industry believe that this policy unleash will help India to become globally competitive and self-reliant. But, amid this positive vibe, there are loads of serious impediments that the industry is struggling to deal with such as intricate duty and taxation structures and regulatory uncertainty.

What is The Roadmap For a Flourishing PCB Ecosystem in India?

Earlier this year, India reached the fifth rank in electronics manufacturing. This is a remarkable achievement when compared to 11th rank ten decades ago. The underlined strengths are indicating that the situation is very optimistic about the potential of India to achieve the target of US dollar 5 trillion economies by 2026 and 300 billion dollars will be contributed by electronics manufacturing. The PCB industry is of immense importance for the ESDM sector globally, claims experts.

Nijhum Rudra Tue, 11/08/2022 - 10:57

Build Simple 12.6V CC/CV Lithium Battery Charger using Viper VP22A Low Power Primary Switcher IC

Switch Mode Power Supplies (SMPS) are one of the most generally used AC-DC Converters on the market as they accept 110V/230V AC as input and convert it to a desirable DC voltage level, making them useful for a wide range of applications. These are omnipresent, from smartphone chargers to lab bench power supplies to medical tools. We've already developed a few SMPS circuits, such as this 5V 2A SMPS circuit, a 12V 1A TNY268 SMPS circuit, and a 12V 1A Viper-based CV Circuit. However, we did not discuss a Constant Current (CC) with a Constant Voltage (CV) power supply in any of those projects. CC and CV configuration is needed to build Lithium Battery Chargers,  in this article we will design and build a 12.6V Li-ion battery charger to charge our 12V battery pack which we built in our previous tutorial. Constant current circuits are extremely helpful as they can be used to safeguard your circuit from overcurrent, as well as charge lithium batteries according to manufacturer requirements. It can also be used as a constant current LED driver to keep your LEDs from burning out. So, in this project, we will be adding in constant current capabilities to our Viper22A-based power supply and will document the entire construction process.

Viper22A Based SMPS Circuit Design Specification

Before we start our SMPS design, we need to shortlist the specifications because different types of SMPS work in different environments and they have input and output specifications. We also need to consider if the SMPS is inside an adapter or if it's in an open environment.

Input Specification

The SMPS circuit we are building will have an AC input voltage rating of 220V-240V as it's the standard Indian specification. This is also the rated input voltage for EU.

Output Specification

The output voltage of the power supply will be 12.6V with 1.3A Constant Current. The output power will be 16.8 watts. As discussed earlier, the SMPS will work in both Constant Current and Constant voltage mode, which means the current will be limited to 1.3A considering how big of a load is attached.

Output Ripple

As the purpose of designing a constant current supply is to use it as a LED Driver or a battery charger, the output ripple specification will not matter that much. But if you are using this power supply to power highly sensitive electronics, then you need to consider that a good power supply will have a maximum output ripple voltage of 30mV pk-pk. The output ripple voltage depends upon two major factors which are the Transformer construction and the output filter, so we need to consider the two factors in our design. We are going to order the transformer from a professional manufacturer and for the capacitor, we are going to use a low ESR value capacitor.

Input & Output Protection

There are various types of protection circuits available that can be employed for the safe and reliable operation of the SMPS, but the protection system can be divided into two categories: input protection and output protection. The input protection circuit protects the SMPS from the transient and high input voltage. The output protection circuit protects the load device from getting damaged. Input surge protection will be used with a maximum operating input voltage of 275VAC. Also, to deal with EMI issues, a common mode filter will be used for blanking out the generated EMI. On the Output side, we will include short circuit protection and over-voltage protection circuit.

Selection of the SMPS Driver IC

To build a proper working SMPS we will be needing a PMIC or power management IC, and as we have discussed earlier, we will be using the Viper22A SMPS controller IC. The circuit will have the following features. 

  • 16.38W output, 12.6V CV and 1.3A CC.
  • Standard (220-260) V input voltage rating
  • Input surge protection. Maximum input voltage 275VAC.
  • Output short circuit, overvoltage and overcurrent protection.
  • Constant voltage operations.

From the above requirement, we have a lot of ICS to choose from but as we have mentioned earlier we will be using the viper22A IC as it is cheap and readily available in the market, and from the datasheet of the Viper22A, we can see that the power capabilities are within our requirement for the DIP Package, so we will be using that IC.

Viper22 IC Power Capabilities
Main Type SO-8 DIP-8
European(195-265 Vac) 12W 20W
US / Wide Range(85-265 Vac) 7W 12W

In the above image, the typical power capabilities of the Viper22A IC are shown. As you can see, the DIP-8 version IC with an input voltage of 195-265V can deliver 20W of power. The pinout of the Viper22A IC is given below.

Viper22A IC Pinout

Components Required to build a 12v lithium battery charger

The components required to build the Viper22A-based SMPS circuit are listed below. Most of the components that are used to build this project can be found in your local hobby store or any online store. The Complete BOM of the Viper22A-based battery charger circuit is shown below.

  • VIper22A Driver IC - 1
  • EE25 SMPS Transformer - 1
  • 0.15nF, 250V AC Capacitor - 1
  • 100uF, 16V Capacitor - 2
  • 10K Resistor-1
  • 1K Resistor - 1
  • 680R Resistor - 1
  • 4.7K Resistor - 1
  • 10 Ohms Resistor -2
  • 180K Resistor - 1
  • 2.2K resistor - 1
  • 22uF,400V Capacitor - 1
  • 27K Resistor - 1
  • 3.3uH,1A inductor -1
  • 4.7uF,16V Capacitor - 1
  • 9.1K Resistor - 1
  • DB107G Bridge Rectifier - 1
  • FR107 Fast Recovery Diode - 1
  • LM358 Op-amp - 1
  • EL817 Optocoupler - 1
  • SR360 Schottky Diode - 1
  • T500mA Slow Blow Fuse - 1
  • TL431 - 1
  • UF4007 - 1
  • LED Red - 1
  • LED Green - 1
  • 1R,2W Resistor - 3
  • 1000uF,16V Capacitor - 1
  • 0.1uF,16V Capacitor - 4

Circuit Diagram of the Viper-Based CC/CV Battery Charger

We started designing our circuit by using the power supply design software from Viper. You can download VIPer Design Software Version 2.24. You need to be specific with this version because the latest version of this software from ST does not support the viper22A IC, by selecting the input and output specification, the complete power supply circuit can be generated. The complete circuit for the Viper22A-based CC/CV Battery Charger is shown below.

 

Viper22A based CC/CV SMPS Circuit Diagram

 

  1. Input Surge and Fault Protection
  2. Input Filter
  3. AC-DC Conversion
  4. Driver Circuit or Main Switcher IC
  5. Clamp Circuit
  6. EMI Filter
  7. Secondary Rectifier
  8. Filter Section
  9. Feedback section
  10. Constant Current Section

Input Surge and SMPS Fault Protection

The input surge and fault protection section consist of three parts: First is the Slow Blow Fuse, next is the 10 OHM NTC and finally, we have a 7mm MOV(Metal Oxide Varistor) of 250V, as the max input voltage rating of the VIper22A IC is 265V. During a high voltage surge, the MOV will become dead short, and the fuse will blow up protecting the IC from the high input voltage. The fuse used in an SMPS circuit will have to be a slow-blow type fuse because there will be a huge current flow when the circuit is powered on because of the capacitor. NTC is there to limit the inrush current that is flowing in the first two or three bootup cycles.

Input Filter

For the Input filter, we are using a 0.15nF,250V AC Capacitor. The capacitor is an X-type Capacitor and we have used this type of capacitor in our Transformer less power supply design.

AC-DC Conversion

The main component of the AC-to-DC converter is a Full Bridge Rectifier and for this reason, we are using the DB107 1A Rectifier IC. To filter the noisy DC signal to a smooth DC signal, we are using a 22uF,400V Low ESR Capacitor.

Driver Circuit or Main Switching IC

The Viper22A is the main switching component of our power supply and the device needs power from the auxiliary winding of the transformer to start the switching process. Once the switching voltage is there and it's greater than 9V the switch across the main transformer starts with a built-in MOSFET.

Clamp circuit or Transient Clamp Circuit

The transformer itself is a big inductor. And as with any inductor, it creates a high voltage spike during the turn-off period of the transformer, which could damage the Viper22IC. So to prevent this, we need to use a transient voltage suppressor circuit. The D5, R2, and C7 are what make this circuit.

Secondary Rectifier

The High-Frequency output of the Transformer is rectified and filtered by an SR360 Diode D1. The maximum output current of the diode is 3A so it can easily handle the maximum output current of our power supply which is 1.3A.

Filter Section

In the schematic, C3, L3, and C13 make our LC PI filter. The LC filter is what provides better ripple rejection across the output of the supply.

Feedback Section

The Total feedback section consists of TL431(U2), LM358N(IC1), PC817(OK2), and two LEDs LED1, LED2. The TL431 senses the output voltage and puts out a constant voltage of 2.5V. Now, this 2.5V is compared with the output voltage by op-amp (IC1B), and the feedback from the voltage is lowered with a voltage divider (R7 and R5). Now when the voltage at the non-inverting input of the supply is greater than the inverting input, the output of the op-amp goes high and the LED1 lights up indicating that it's in Constant Voltage or CV mode. Now the optocoupler turns on and it provides some voltage on the feedback pin of the VIPER22A IC and the viper adjusts its switching speed accordingly.

Now for the constant current portion, the operation is almost the same as the constant voltage. The resistors R8, R9 along with R13 form a voltage divider. And this voltage is compared with the voltage drop across the 0.33Ohms resistor, which we have made by paralleling three 1 Ohms resistors. Now if the Voltage at pin3 of the op-amp is higher than pin 2 the output of the op-amp goes high, the LED2 turns on and now controls the optocoupler and the charger module is working in the CC mode.

PCB Design for 12V Battery Charger using Viper22A 

The PCB for CC-CV Charger is a simple single-sided board. I have used Eagle to design my PCB but you can use any Design software of your choice. The 2D image of my board design is shown below.

PCB Design for Viper22A Based CC, CV Power Supply

The Top and bottom side of the PCB is shown above. As you can see on the bottom side I have used polygons to ensure sufficient current can flow through it, the thick polygons also act as a heat sink to dissipate heat. The complete design files with the schematic PDF can be found in the link given below.

  • Download Gerber files of Viper22A Based CC/CV Flyback Converter PCB

Viper22A Based CC/CV Flyback Converter PCB

For convenience and testing, we have made a handmade version of the PCB and the top and bottom side after soldering is shown above.

Transformer Construction for the Viper22A-based SMPS Circuit

As we have mentioned earlier, you need the viper design software to set the Input and output parameters, once you have set that you need to click on the Transformer button.

Transformer Construction for the Viper22A based SMPS Circuit

Once you click on the transformer button, you will get something like the image shown below.

viper design software transformer design

The Core is E20/10/5 with an air gap of 0.68mm. The primary inductance is 0.72mH. The primary turns ratio is 113 Turns with 31 AWG wire. The Auxiliary Wire is 22 Turns with 44 AWG wire. The output windings are made with 19 Turns with 21 AWG wire. With all the information from the Transformer Design tool, we ordered our transformer from a professional construction house and after a week we received our consignment, and the transformers look something like the image shown below.

viper design software transformer

Testing the Viper22A Based SMPS Circuit

To test the circuit, we have our test setup which is shown below. To measure the output voltage, we are using a multimeter and to measure the current we are using a clamp meter.

Viper22A Based SMPS Circuit Testing

Now as you can see the circuit is powered on and, on the output, we are getting 12.7 volts which make this circuit perfect for 3S battery pack charging.

Viper22A Based SMPS Circuit Board Testing

Now as you can see in the image, we have attached the load to the output of the power supply. The load is two 10 ohms resistors in parallel which makes it 5 ohms load and as you can see there is a 900mA current flow through the resistor. The value of the current is lower because at the time of building the circuit, we did not have a 9.1K resistor with us and we need to put some resistors in series to get that 9.1K value and that is the reason why we are not getting full 1.3A at the output.

Problems while Building the Circuit with Solutions

There are many problems that we have encountered while building the circuit. The biggest of them all is duplicate ICs that we have got our hands on. In the original IC, pin no 5,6,7, and 8 are shorted, but in the duplicate IC pin no 7 and 8 are shorted, and pin no 5 and 6 had no connection with pin 7 and 8.

Next, you need to observe the auxiliary voltage of the transformer. If the auxiliary voltage of the transformer is not greater than 9V the IC will not start its operation.

The next problem was with the constant current design. The Viper IC is not designed for constant current operation, and we had to add an additional circuit to enable constant current mode for Viper IC. On the other hand, if we had used a Power Integrations IC, it would have a current limiting functionality built in, but the viper IC doesn’t have that functionality.

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The Biggest Challenge to Deploy AI and IoT Solutions in India is its Large Geography

AI and IoT is not a buzzword anymore, feels many industry experts. This is because it is commencing a new market same as what cellular devices have done for seamless communication. These days, people are dependent on real-time information and not on historical records. Technology helps the availability of accurate information anytime and anywhere. But, some industry experts also opine that India is very slow in adopting innovative technologies when compared to Australia, US, Europe, and other Asian countries like China, Taiwan, and Vietnam.

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