I am a bit out of my depth here. I need perform an electrochemical reaction under varying waveforms. I have never had to set something like this up before. I have a DC power supply, a waveform generator and an electrochemical cell with an anode and cathode. I just need to determine the proper way to connect these in order to control the waveform going through my electrochemical cell. Can anyone suggest a way to do this properly?
How to properly connect a waveform generator with a DC power source for use in electrochemistry
- Thread starter NLundquist
- Start date
Welcome to AAC.
Your problem is underspecified. What are the characteristics of the waveform that need to be applied to the cell? Is is it based on input or some parameter measured in the cell?
What is the current and/or voltage required?
What are the minimum and maximum frequencies required?
Do you have a drawing of the cell?
What are the make and model numbers of the power supply and waveform generator?
Do you have an oscilloscope?
You can certainly get help here with this problem but more information is needed to make the possible.
Your problem is underspecified. What are the characteristics of the waveform that need to be applied to the cell? Is is it based on input or some parameter measured in the cell?
What is the current and/or voltage required?
What are the minimum and maximum frequencies required?
Do you have a drawing of the cell?
What are the make and model numbers of the power supply and waveform generator?
Do you have an oscilloscope?
You can certainly get help here with this problem but more information is needed to make the possible.
Thankyou!
The electrochemical cell is basically two platinum electrodes in hydrochloric acid. The point of the experiment is to apply different waveforms and switching frequency's to the system in order to produce platinum chloride compounds directly from the electrode. The reaction has been shown to work using a 50 Hz sine waveform in previous work. I want to compare the efficiency of the same reaction when i alter the waveform and frequencies applied to it. An image showing what the cell looks like is shown below.
The minimum voltage required is around 1.3V but anything higher is fine. The minimum frequency range I would like to test is from 10 Hz to 200 Hz however testing outside this range would also be beneficial.
I do not have an oscilloscope. The waveform generator is a GW function generator Model: GFG-8019G. The power supply I have is a TTi PLH250-P DC Power Supply 250 V 0.375A. I've attached images of both devices. Im not sure if I need to use the power supply with the function generator or if i can just use the function generator by itself.
I'm just not sure how to connect the function generator to my electrochemical cell to apply the desired wavefunctions through it.
Thankyou
The electrochemical cell is basically two platinum electrodes in hydrochloric acid. The point of the experiment is to apply different waveforms and switching frequency's to the system in order to produce platinum chloride compounds directly from the electrode. The reaction has been shown to work using a 50 Hz sine waveform in previous work. I want to compare the efficiency of the same reaction when i alter the waveform and frequencies applied to it. An image showing what the cell looks like is shown below.
The minimum voltage required is around 1.3V but anything higher is fine. The minimum frequency range I would like to test is from 10 Hz to 200 Hz however testing outside this range would also be beneficial.
I do not have an oscilloscope. The waveform generator is a GW function generator Model: GFG-8019G. The power supply I have is a TTi PLH250-P DC Power Supply 250 V 0.375A. I've attached images of both devices. Im not sure if I need to use the power supply with the function generator or if i can just use the function generator by itself.
I'm just not sure how to connect the function generator to my electrochemical cell to apply the desired wavefunctions through it.
Thankyou
OK, so 1.3V that’s the electrolysis threshold. It is possible that the function generator alone will do the job, nit if it doesn’t, the power supply is of little use—you’d need an amplifier.
Use the 50Ω output, and make some empirical tests. You can even just use non-precious metal electrodes in slightly salty water in a beaker to see if you can get electrolysis to happen. That would be a good first pass check on the feasibility.
What metrics do you need to collect? What accuracy and repeatability?
Will you be controlling the temperature?
Use the 50Ω output, and make some empirical tests. You can even just use non-precious metal electrodes in slightly salty water in a beaker to see if you can get electrolysis to happen. That would be a good first pass check on the feasibility.
What metrics do you need to collect? What accuracy and repeatability?
Will you be controlling the temperature?
After reading a little more it did occur to me we may not need the power supply at all. Maybe I will just connect the waveform generator to the electrolysis cell and test it first and if its not enough then I could implement an amplifier. I have managed to get an amplifier lent to us. It is +/-10V 1 AMP. I guess my first issue is that im unsure about exactly how I connect the wavefunction generator to the cell. I assume the correct output is the TTL/CMOS output and I assume that CMOS is the preferred option to use of the two?
The temperature will be held at 25 degrees Celsius for the initial experiment. However if it works, I will likely be controlling the temperature and testing its effect on the outcome. For the initial test I would just like to prove that it works or doesn't however once I have done this I will be looking to make it more repeatable and accurate.
As for monitoring the first reaction:
For the initial test we are looking to observe the degradation of the platinum electrode into solution. As a simple first test, this should be observable just through sight as its only small wire electrodes. The electrodes will be weighed before and after as well to determine if any mass has been lost. We should also see an equal amount of bubbling from both electrode and the current running through the cell should decrease due to the wire getting smaller as the experiment progresses. We will then be analysing the electrolyte after the experiment to determine the amount of the desired species we produced. Once ive confirmed its working I will look towards finding a more accurate method to monitor the progression of the reaction.
Thankyou for your help, its much appreciated.
The temperature will be held at 25 degrees Celsius for the initial experiment. However if it works, I will likely be controlling the temperature and testing its effect on the outcome. For the initial test I would just like to prove that it works or doesn't however once I have done this I will be looking to make it more repeatable and accurate.
As for monitoring the first reaction:
For the initial test we are looking to observe the degradation of the platinum electrode into solution. As a simple first test, this should be observable just through sight as its only small wire electrodes. The electrodes will be weighed before and after as well to determine if any mass has been lost. We should also see an equal amount of bubbling from both electrode and the current running through the cell should decrease due to the wire getting smaller as the experiment progresses. We will then be analysing the electrolyte after the experiment to determine the amount of the desired species we produced. Once ive confirmed its working I will look towards finding a more accurate method to monitor the progression of the reaction.
Thankyou for your help, its much appreciated.
As Ya’akov mentioned it is better to use the 50 Ohm output. I guess, if you use pure ac, the efficiency of the operation may be low. Using the regular output you can add a dc-offset. Also use a sine wave. Only then you exactly know which frequency you are using. If you apply a rectangular signal like CMOS you have a mix of frequency components. ( fundamental and the overtones associates with a rectangular signal).
Read PDF in this post about electrolysis on AC current.
I have taken the advice you use and attached a picture demonstrating the way i have set the system up.
When I turn it on and the frequency is set at 0, I notice that the bubbling is occurring back and forth from one electrode to the other, strongly suggesting an AC frequency is applied even though the frequency is set to 0.
Once i try to turn the frequency dial, the bubbling stops switching and remains strong only at one electrode. This suggests a DC current is passing through the cell.
When the frequency is turned on the int counter appears to match what i want it to, but the external counter is 0. To me this says that the system is set to what i want it to be but its not being applied through the cell.
The system is set to sine waveform, frequency range of 10-100 Hz. Im using the 50 Ohm output (Far right output) as suggested.
Im just really unsure why the frequency is not being applied once I turn it up but it appears to be working when its set to 0.
Any help with this would be greatly appreciated.
Thanks,
Nic
When I turn it on and the frequency is set at 0, I notice that the bubbling is occurring back and forth from one electrode to the other, strongly suggesting an AC frequency is applied even though the frequency is set to 0.
Once i try to turn the frequency dial, the bubbling stops switching and remains strong only at one electrode. This suggests a DC current is passing through the cell.
When the frequency is turned on the int counter appears to match what i want it to, but the external counter is 0. To me this says that the system is set to what i want it to be but its not being applied through the cell.
The system is set to sine waveform, frequency range of 10-100 Hz. Im using the 50 Ohm output (Far right output) as suggested.
Im just really unsure why the frequency is not being applied once I turn it up but it appears to be working when its set to 0.
Any help with this would be greatly appreciated.
Thanks,
Nic
There appears to be no offset. Attached are images showing the settings i have when i do this.
I notice it appears to be AC current in the range of 0-5 Hz but as I go above this it seems to be completely DC. Regardless it always says EXT counter as 0 but INT counter as what i set the frequency to. Im not sure if this is because the EXT counter is for something else or wethers its outputting the signal i want.
I notice it appears to be AC current in the range of 0-5 Hz but as I go above this it seems to be completely DC. Regardless it always says EXT counter as 0 but INT counter as what i set the frequency to. Im not sure if this is because the EXT counter is for something else or wethers its outputting the signal i want.
