The Engineering Projects

So you've installed a beautiful new solar energy system around your house or property. You're saving tons on your electric bill and never have to worry about blackouts, power surges, or planned outages—you control your power source now. Here's the problem: What do you do when you need to dispose of everything?

Eventually, you will need to replace the solar panels and the solar battery, which powers the whole system. Disposing of solar batteries isn't exactly simple, and it needs to be handled with the utmost care. But it is easy to navigate if you know the proper steps to take—and what to avoid. Here's our complete guide.

Disposing of the Battery

If you've recently purchased a solar energy system or portable solar generator, you know the current solar battery price . It's not low, but it has improved in recent years as technology evolves. Lithium batteries are rechargeable, but they don't last forever. 

Once your lithium battery dies or needs to be replaced, you should first call your local waste management authority. They will be able to direct you to the proper place to dispose of your solar battery safely.

Inquire About Recycling Alternatives

The lithium batteries often used for solar generators contain tons of materials that would adversely impact the environment if they were left to decompose in landfills. The National Library of Medicine warns about metals such as copper, nickel, and lead. Other concerning components include toxic and flammable organic chemicals that contain compounds like LiClO4, LiBF4, and LiPF6.

For this reason, you should ask the waste management authority about recycling options. Those chemicals must be disposed of properly, and many metals can be used elsewhere in other construction and manufacturing projects.

What Can Be Recycled?

Metals currently comprise about 13% of all that is thrown into the recycling . Still, if people took the time to learn how to recycle complicated objects such as lithium batteries, that number could rise even higher. Plenty of the materials used to make lithium batteries for solar generators can be recycled. Those that can be reused include:

• Glass, which is the primary material used in the manufacturing of photovoltaic panels and can be found inside lithium batteries

• Aluminum, which is 100% recyclable

• Copper, nickel, and lead are all largely recyclable, and copper can be 100% recycled and reused.

Knowing what you can recycle is the first step to figuring out how to recycle it properly. 

The Cost of Not Recycling

As landfills rise, the cost to our environment grows. When items like lithium batteries containing dangerous compounds are thrown into landfills, they can decompose, and those compounds can render everything they touch toxic. 

The dangers of landfills include destroying natural animal habitats, producing toxic methane gas, contaminating water supplies, the production of ammonia, and more. Make sure to dispose of your battery safely.

Making the Smart Choice

You can make money from recycling your lithium battery, and you'll be helping save the environment in the process. There's no reason not to follow these steps.

Hello friends, welcome back to our tutorials on PLC ladder logic programming. Today we will talk about batch process control and take one project from our factory to understand, implement, and simulate. So without any further delay, let’s jump into the tutorial by asking what is batch process is if it is different from other online processes. Well! The batch process is defined as a process that starts by operating continuously till the end of the cycle without any interaction with the users. For you guys, it’s cool to know that most of the processes you might meet in the industry of batch-type processing. Do you like me to give an example? Well! The Silo cement process is a batch process, and food and beverages manufacturing are also good examples of batch processes. So what do we have today of the batch process? It’s a batch-mixing process in which we mix liquids with a mixer. The process utilizes a couple of sensors and actuators to be performed, as we will see in the next pages. So let’s go further in our project.

Mixing batch process

Figure 1 shows a beautiful scene of the process that shows all components, including actuators, sensors, switches, and indicators. As you can see, friends, two pine lines supply the liquids to mix. For each line, a flowmeter switch tells the amount of liquid filled so far. It also shows one pump for each line to draw the liquid from the source to the mixing tank. Also, the liquids are mixed in the middle of the tank thanks to a mixer installed vertically in the middle of the tank. In addition, you guys notice the proximity switches installed on the top right of the tank to detect the level of the liquid .inside the tank to recognize two levels of the liquid. One is the low and the other for detecting the high liquid level inside the tank. Also, at the very bottom of the tank, you can see another pump installed underneath the tank at the center to drain the mixed liquid out from the tank. And also, the drainage pipe has a flowmeter switch to determine the amount taken out from the tank. On top of that, on the left, you see the control panel that helps operators start and stop. Set parameters of the process in addition to showing the process status throughout the process run, idle, stop status, the amount of liquid in the tank, and the amount of liquid drawn from each line. I know you are now gossiping ohh, that time we have a large project and too many things to control. No, no, brothers, it’s a simple process but let us go through the requirements and divide the work into parts and go do part by part together.

Mixing batch process operation

Every process has its logic or philosophy or the logical narrative that the client will tell or the customer. Your turn is to listen to him and ask for every details to make sure you have everything you need to start. Please validate your understanding and question your client about everything you need to start with a good understanding of the process and the requirements. The process between our hands to do today is nothing more than a batch process performed manually by the operator’s fingers. You will make it automated using PLC so that the operator will narrate to you what he does from the start to the end of the process cycle to complete the process. First, he starts by hitting the commencing button that starts the pumps P1 and P2 to draw liquid until the level of liquid in the tank reaches 90%, at which we should mark the tank as full and stop the pumps and the filling process. The next stage is to command the mixer to run for a while, which is decided by the client. In our project, we were told to run the mixer for 8 seconds. Afterward, the drainage pump runs to take out the mixed liques until the tanks are empty. At that time, we can repeat the process by hitting the start push button again for another cycle or continuously running cycle after cycle automatically. Also, you need to know the operator can stop the cycle at anytime. The indicator and BCD screen should tell the operator the current status and the amount of liquid input and output to and from the tank.

The process inputs and outputs

Table 1 lists all inputs and outputs of the mixing batch process. The first column shows the name of the Ios, the 2nd column presents the IO addresses, and the 3rd column informs a description of the IO.

 Batch Mixing Process with Ladder Logic

That can not be counted as a large-scale project. However, let’s deal with it as a large one. So, professionally will take it into parts to simplify our mission. The project will be divided into three small projects, So let us go through each part until we get the whole process done.

The filling process

In the filling part, we need to pump P1 by hitting the start push button until the level in the tank reaches full status when the liquid level becomes 90%. At then, pump P1 should be stopped. You see, guys, dividing the whole process into small, simple sub-processes make it easier to implement.

Implementation and testing

Figure 3 shows the ladder logic of the first part that controls the filling process. You see, guys, it simply latches the pump output O:2/1 by using the start push button and stops by either hitting the stop push button to stop the run or by reaching the full position by counting the generated pulses from input I:1/5 till it counts what is equivalent to 90% of the high level of the tank. So let us test that part and see if it is functioning well or if we need to amend the code we wrote.

Testing part 1 for the filling tank

Success is the result of testing part 1, as in figure 4. You see, guys, the tank kept filling by latching the pump P1. But when the counter accumulator reports 90% of the tank is full, the full flag stopped pump P1 as it is designed for that part. Now let’s move to the next part.

Emptying the tank

In this second part of the project, we are required to control the emptying process of the tank. The sequence is like when the full status of the tank level is reached, which is already achieved in part 2, the mixer should be activated for 8 seconds, and then the pump P2 will be energized to drain the tank till reaching to zero level of the tank at then the pump P2 will be stopped. So let us discuss the ladder code of that part. 

The ladder logic of the emptying process

Figure 2 shows the code we wrote to implement the draining process. We started displaying the code from rung three because rungs 1 and 2 are just like part 1 to fill the tank. In Runge 3,  we display the tank level by copying the counter accumulator value C5:1.ACC to the O:4 output of the BCD to 7 segment display. In Runge 4, we use timer T4:0 to count the 8 seconds during which the mixer will run, as in Runge 5. After the 8 seconds of mixing, pump P3 is energized to drain the mixed liquid as in runge 6. When you empty the tank, note down till reaching zero level as in Rung 7. At that time, pump P3 will have been stopped. I hope testing this stage goes okay, as we will check in the next section.

Testing the emptying process of the mixing batch process

As you see in figure 6, the emptying process is okay. The liquid is drained from the tank starting from the full position till reaching zero level position thanks to control of the drainage pump P3.

Figure 7 shows that the draining process continues till the liquid is drained from the tank.

The last part of having a continuous operation

After completing the whole batch process cycle, starting from filling the tank and ending with draining the liquid out from the tank, it is required to let the process run automatically, meaning the cycle repeats forever unless the operator requests a stop. Figure 8 shows the ladder logic code we added to automate the cycle. The amendment we have added in Rung 1 shows that to start the process by hitting the start push button; we added a flag B3:0/2 that indicates the end of the last cycle to start a new cycle automatically.  Also, we have added in rung 2 the code for the Idle process status indicator when there is no activity of either the mixer or pumps.

Testing the last stage

Figure 9 shows the idle status when there are no activities and the mixer and pumps are stopped.

I could not find a way to show you the continuity of the cycle, which is the target of the last part, because images can not do that. Instead, it should be through videos. So I hope you go through this tutorial and write the code or even your code and enjoy running the project on the simulator to see the cycle run autonomously. Thanks, my friends, for following me till that point on this tutorial, and I hope to meet again soon with a new exciting one.

Hi, my friends, and I hope you are doing great today! We have today one interesting topic that you have seen everywhere you go, but you might not notice it! That is what the so-called binary coded decimal (BCD) is. So what’s that? Well! When you are waiting for your turn at the front of a wicket in the bank. You see 7-segmented displays that show numbers in digits. So how do these counter displays work? The BCD is the idea behind how these displays work. Numbers can be represented in many formats. Some of these formats are readable for the public which is the decimal pr the digits 0, 1, 2, .., 9. On the other side, there is another number format which is not readable to general people. Still, it is essential for computation and computer processing like binary format and hexadecimal formats. Without going deeply into number format, we want to let you guys know that. The numbers are mostly displayed for people in digits or decimal format 0-9 but processed in binary by computer. So converting that binary format to decimal format is crucial in such an application. This tutorial shows you how plc can help perform as a BCD controller. 

BCD representation

As we have two formats to convert from to, figure 1 shows the digital format 0-9 that are displayed in the first column while the binary equivalent is represented by 4 bits A, B, C, and D. but we need to represent the 7 segment operation how it looks like and how it has been implemented in the past and in the present using the evolving development in computation and electronics. From there, we can jump to how the PLC can control the 7 segments and that kind of display.

The 7-segment display

Figure 2 images a 7-segment display that shows 7 LEDs a, b, c, d, e, e, and g. for displaying a digit from 0 to 9 we need to illuminate some of these lLEDs to shape the required digit.

For example, digit 1 can be formed by lit LEDs b and c while all other LEDs are off. Also, table 1 shows the states of the 7 LEDs for digits from 0 to 9.

Table 1: the equivalent states of the 7 segments for digits 0-9 

Also, guys, Figure 4 Combines the digits, the equivalent binary inputs, and the outputs represented by the states of the 7 LEDs to form the number or the digit we need to display.

The logical circuit of the 7 segment 

The BCD to 7-segment decoder has been implemented by combining logic gates, as shown in figure 5.

This decoder is now available in the market as an integrated circuit IC as shown in figure 6. As you see, guys, the IC has the 4 binary inputs, and all the 7 LEDs, a, b, c, d, e, f, and g, come out as an output signal that will be connected to the 7-segment display to show the numbers or digits. So now it is the time for my friends to show how PLC can perform this piece of cake job by assigning 7 inputs from its input module to the 7 outputs that will be directed or connected to the 7-segment display. So let’s go doing this mission.

BCD to 7 segments using PLC

You can see, guys the project we are going to implement using ladder logic programming includes eight inputs and eight outputs. The requested digit can be formed by set the related inputs to high, and the outputs will be set accordingly. Then the outputs are connected to the 7 segments to display the requested digit.

The logic of the BCD to 7 segment project

First of all, guys, look at figure 8, which depicts how we design such a system. The inputs to the 7 segments IC will be the 4 binary bits A, B, C, and D, which are coming from the PLC outputs. These 4 bits will decide the states of the 7 outputs a, b, c, d, e, f, and g, which will be forwarded to the 7-segment display to display the target digit 0 to 9.

The logic is pretty simple my friends; it is straightforward because all that we need to do is to relay the inputs the user or the operator requested via the inputs switches of the PLC to the outputs of the PLC as shown in figure 9.

The ladder logic code of the project

Figure 10 shows the rungs of the ladder program of the BCD to 7-segment converter. As you see, guys, the code is very easy. It is nothing but assigning each input to its mate of the output for the eight bits that will be forwarded to the 7 segments to form the number or the requested digit.

Testing the BCD to 7-segment decoder by PLC

Figure 11 shows one of the tests to display digit 7. You can see, guys, that the output was 11100000, equivalent to the digit 7. That output will be forwarded as an input to the BCD to 7 segment IC. That results in setting the outputs a, b, c, d, e, f, and g and, in turn, displaying the digit 7 on the 7-segment screen.

Testing the hexadecimal format

The project can display the hexadecimal format also, as shown in Figure 12, which shows the Hexadecimal value FF that is equivalent to 11111111 in the binary format. So all the outputs are high, as shown in the results.

Finally, I would like to thank you all for following the tutorial until the end. I hope you enjoyed the idea and went step by step to code the project and practice simulating it as usual ti boost your capability of the PLC ladder logic programming.