Circuit building - Do not know where to post this

Thread Starter

rakkiran

Joined Mar 28, 2023
14
Hello everyone,
I am new to electronics/electrical world. And am trying to build a circuit which is attached in the image. But the issue is I do not know where to start with. I tried circuit lab but am unable to build the circuit as all components are not available. Can somebody guide me on how to design the circuit physically so that I can perform experiments using this.
Any suggestions in this regard are appreciated.

Thank you all in advance,

Regards,
Raj Kiran.
 

Attachments

Thread Starter

rakkiran

Joined Mar 28, 2023
14
Hi,
Thanks for the heads-up, but yeah, I will take care of the high voltages that are being generated. Although at the beginning stages, I will perform my experiments using only smaller voltages (I have a DC power supply of 30 volts). I tried making virtual circuits (on Circuit Lab), but all the components are not exactly available on the platform (or may be I do not know exactly how to use those platforms properly). Kindly direct me or guide me on how to build the circuit, as this is crucial to complement my experiments.
Whereas there is also another circuit which has similar outcome as the earlier, so I have to build anyone of the circuits to perform flow visualization studies.


Regards,
Raj Kiran.

MODERATION: This post was moved from a new thread to this one which it is an answer to. @rakkiran please find the thread you are replying to and answer in it instead of creating a new one. You can find all of your own content in your profile if you are otherwise lost about where the thread is, or you can ask a moderator for help. Welcome to AAC.
 

Attachments

BobaMosfet

Joined Jul 1, 2009
2,110
Hello everyone,
I am new to electronics/electrical world. And am trying to build a circuit which is attached in the image. But the issue is I do not know where to start with. I tried circuit lab but am unable to build the circuit as all components are not available. Can somebody guide me on how to design the circuit physically so that I can perform experiments using this.
Any suggestions in this regard are appreciated.

Thank you all in advance,

Regards,
Raj Kiran.
Title: Understanding Basic Electronics, 1st Ed.
Publisher: The American Radio Relay League
ISBN: 0-87259-398-3
 

Wendy

Joined Mar 24, 2008
23,415
We all start somewhere, for the power supply I would seriously considering using a USB cube. Most everything power supply related is already taken care of in one little box. After that I would consider a protoboard similar to this:

Protoboard 63 columns.png
they are fairly inexpensive and you can reuse all of the parts after you are done. I frequently post projects using these gadgets and post them on an index.

Wendy's Index
Wendy's Protoboard Circuits Cookbook.

If you look at the front of the general electronics chat you will see several indexes I have posted over the years.
I am a firm advocate of buying things off the shelf. you can buy variable power supplies much cheaper than you can build them. I tend to collect wall warts (The power supplies the plug directly into power outlets) for fixed voltages, again much cheaper. Eventually you will want to learn how to solder, but that is a subject for another thread.

If you ever want to tag a user and get help just put an @ symbol in front of their user name like so @Wendy , and they will be notified.
 
Last edited:

MisterBill2

Joined Jan 23, 2018
18,167
Avery good way to find assistance is to include a description of what the ultimate purpose of the circuit is, what is it intended to do? Knowing the desired results can go a long way toward creating something to produce those results.
 

Wendy

Joined Mar 24, 2008
23,415
Agreed, it may sound weird (and frequently is) there is an informal contest amongst the problem solvers in this group.
 

Thread Starter

rakkiran

Joined Mar 28, 2023
14
Hello All,
The purpose of building the circuit is to perform flow visualization to complete my experiments @Wendy @MisterBill2. Flow visualization is technique in Fluid Mechanics where the flow structures are studied by injecting some visible particles into the fluid medium. Here this circuit generates hydrogen bubbles near cathode and these bubbles are used as seeding/injecting particles to understand the phenomena taking place.

And as I already mentioned this circuit building will aid me in completing my PhD thesis. As I do not have background of electrical/electronics, and as a lone wolf am not enough to learn and do stuff, so am seeking help from online platform.

Regards,
Raj Kiran.
 

Ya’akov

Joined Jan 27, 2019
9,069
Hello All,
The purpose of building the circuit is to perform flow visualization to complete my experiments @Wendy @MisterBill2. Flow visualization is technique in Fluid Mechanics where the flow structures are studied by injecting some visible particles into the fluid medium. Here this circuit generates hydrogen bubbles near cathode and these bubbles are used as seeding/injecting particles to understand the phenomena taking place.

And as I already mentioned this circuit building will aid me in completing my PhD thesis. As I do not have background of electrical/electronics, and as a lone wolf am not enough to learn and do stuff, so am seeking help from online platform.

Regards,
Raj Kiran.
At the voltages your schematic suggests, you are going to evolve a lot of hydrogen with a handy oxygen supply right there with it. Do you have a plan for dealing with the very real explosion hazard? Have you considered something along the lines of a sintered tube with nitrogen, or even CO₂?

Your current idea has the potential for unintended and potentially terminal excitement.
 

Thread Starter

rakkiran

Joined Mar 28, 2023
14
At the voltages your schematic suggests, you are going to evolve a lot of hydrogen with a handy oxygen supply right there with it. Do you have a plan for dealing with the very real explosion hazard? Have you considered something along the lines of a sintered tube with nitrogen, or even CO₂?
Thanks for the warnings. I did not considered explosion or hazard but yeah I do know that I will be handling very high voltages and hydrogen is highly flammable.
I have performed the same experiments with a 30-35V DC supply but the bubble density were not quite enough for the experiments. A minimum of 50-70 V are required for this method.
And after doing some literature, I came across these circuits and I am stuck there.

Your current idea has the potential for unintended and potentially terminal excitement.
I did not understand this part, is this comment about the circuit behavior?
 

Ya’akov

Joined Jan 27, 2019
9,069
Thanks for the warnings. I did not considered explosion or hazard but yeah I do know that I will be handling very high voltages and hydrogen is highly flammable.
I have performed the same experiments with a 30-35V DC supply but the bubble density were not quite enough for the experiments. A minimum of 50-70 V are required for this method.
And after doing some literature, I came across these circuits and I am stuck there.


I did not understand this part, is this comment about the circuit behavior?
It refers to the ”excitement” of the explosion, and the “terminal“ nature of the outcome—that is, end of life.

Given the danger of hydrogen gas, please consider something like this as an alternative—cheap, easy, and ready to go. No high voltage, no hydrogen. You can get various configurations and bubble sizes.
 

MisterBill2

Joined Jan 23, 2018
18,167
OK, Now I have an idea as to what it is supposed to do. It is intended to electolyze water to produce bubbles.
The exact function is to switch on the power for brief times so as to only make a few bubbles. That circuit is a multivibrator used as a timer to drive an opto-isolator that switches on a mosfet transistor to supply the high voltage DC to a bubble generating wire in a conductive tank. Depending on how accurate the time needs to be, and the frequency of the pulses, most of the circuit can be replaced by a simple normally open push button switch. As shown, it still needs a source of those pulses, so that circuit alone will not deliver the function that you ask for.
AND, BE AWARE THAT THE SUPPLY WILL BE DELIVERING ABOUT 300 VOLTS DC AT SOME USEFUL CURRENT. So there is a need for appropriate caution.
 

Thread Starter

rakkiran

Joined Mar 28, 2023
14
OK, Now I have an idea as to what it is supposed to do. It is intended to electolyze water to produce bubbles.
The exact function is to switch on the power for brief times so as to only make a few bubbles. That circuit is a multivibrator used as a timer to drive an opto-isolator that switches on a mosfet transistor to supply the high voltage DC to a bubble generating wire in a conductive tank. Depending on how accurate the time needs to be, and the frequency of the pulses, most of the circuit can be replaced by a simple normally open push button switch. As shown, it still needs a source of those pulses, so that circuit alone will not deliver the function that you ask for.
AND, BE AWARE THAT THE SUPPLY WILL BE DELIVERING ABOUT 300 VOLTS DC AT SOME USEFUL CURRENT. So there is a need for appropriate caution.
Thanks for the reply, and your explanation made it sound easy to understand and build. The issues I am facing are how to choose the components and whether they can be assembled on a breadboard (because I have used breadboards earlier). If this setup needs any other equipment, how do I choose it? Because I purchased a bridge rectifier (DF 10S) just looking at 1kV and 1.5A, so is this approach correct or should I be purchasing some specific components for the current circuit?
And more importantly, are they costly?
 

MisterBill2

Joined Jan 23, 2018
18,167
The expensive items are the transformer, which since only the voltage is specified in the drawing, no accurate cost clue is possible, although for a transformer rated at less than an amp it should be less than $50 (USD), and much lower if you can find it surplus or even used. The Mosfet transistor should be less than $10 from some sources, more from the expensive ones, and possibly a cheaper alternate for a similar from some. The filter capacitor will possibly be as much as $10. The two IC devices may be as much as $2 each, or much less from some sellers. The pulse source that is not shown can be a 555 timer IC, about $1, and less than $5 for the other passive components.
But given that there is no hint as to how rapidly the pulses need to be delivered, it is not clear to me if you really need a pulse generator, or if a simple pushbutton could work.
 

Danko

Joined Nov 22, 2017
1,829
I have performed the same experiments with a 30-35V DC supply but the bubble density were not quite enough for the experiments.
Use voltage 30V. Set gap between parallel electrodes (wires) not more, than 1-2 mm.
Bigger gap - energy is spent on water heating in gap, current becomes lower, number of bubbles decreases.
N of bubbles in time is proportional to current, but not to voltage.
You can dramatically increase efficiency by dissolving in water some baking soda.
 
Last edited:

Thread Starter

rakkiran

Joined Mar 28, 2023
14
It refers to the ”excitement” of the explosion, and the “terminal“ nature of the outcome—that is, end of life.

Given the danger of hydrogen gas, please consider something like this as an alternative—cheap, easy, and ready to go. No high voltage, no hydrogen. You can get various configurations and bubble sizes.
Thank you very much for showing concern :)
I would have settled for lower voltages if it had worked out. A picture is attached for a trial with 12V DC supply. I do not have video files with 30V supply and they were much better than the attached picture. And bubble generator cannot be used as the wire arrangement is such that it is wound to the object. So I had to choose this way. Any other methods to achieve the same is much appreciated (just that they should not disturb or add other disturbances to the flow other than the disturbance caused by the wing itself).

The expensive items are the transformer, which since only the voltage is specified in the drawing, no accurate cost clue is possible, although for a transformer rated at less than an amp it should be less than $50 (USD), and much lower if you can find it surplus or even used. The Mosfet transistor should be less than $10 from some sources, more from the expensive ones, and possibly a cheaper alternate for a similar from some. The filter capacitor will possibly be as much as $10. The two IC devices may be as much as $2 each, or much less from some sellers. The pulse source that is not shown can be a 555 timer IC, about $1, and less than $5 for the other passive components.
But given that there is no hint as to how rapidly the pulses need to be delivered, it is not clear to me if you really need a pulse generator, or if a simple pushbutton could work.
Thank you very much for the detailed answer. How should I consider the rating of the components, as I mentioned earlier the rectifier (is it the correct one that I purchased)? The pulse timing is to get time dependent data. It may be added at later stages if I am successful with the initial trials. And the timing will depend on where I want to collect my data. So I can skip if it makes the circuit complicated.
Also, where should I connect these components (breadboard, Veroboard etc.)? Will soldering be sufficient for this job?
A similar circuit is also attached here, but this was an old circuit used in 1960 to perform similar experiments. I think you can get more insight if you have a look.


Use voltage 30V. Set gap between parallel electrodes (wires) not more, than 1-2 mm.
Bigger gap - energy is spent on water heating in gap, current becomes lower, number of bubbles decreases.
N of bubbles in time is proportional to current, but not to voltage.
You can dramatically increase efficiency by dissolving in water some baking soda.
Thank you for the detailed and critical approaches mentioned but following are the things I tried-
The experimental image is attached, and the gap was kept as small as possible. And sodium sulfate was added to the water for more ion availability.
I do not know how to control current, the DC supply I used had a current control setup as well, but when I switched on the circuit, there were no readings in current but the voltage was set to maximum.


Regards all,
Raj Kiran.
 

Attachments

Wendy

Joined Mar 24, 2008
23,415
When I was a kid I did something similar my goal was to blow up a balloon, I ran into some unexpected snags with chemistry (hey I was only 11 or so). It seems salt will make the water conductive which is a must but when exposed to electricity the chlorine atoms ate the aluminum foil I was using for the electrodes, you do not need high voltage (I used 12V) for this experiment but you will need good current and a little IC is not going to be able to provide that. So the first thing you need to consider is what your electrolyte will be in a professional setup I had to service later in life they used potassium chloride. Why do you want to pulse the electricity to these electrodes whatever material they are made from? If you are doing this in a well ventilated area there should be very low risk of explosion. Like I said I was doing it outside where the gases would not accumulate anywhere nor mix. My first question is why are you using a timer for the experiment?
A variable power supply would work pretty well, I should think.
 
Last edited:
Top