Variable Resistance Circuit SOLVED

Ok first off I'm a complete electronics novice so please take that into account when/if offering advice/answers please lol. Now my issue is that I'm trying build 2 colloidal silver makers, one that's 30VDC and one that's 30VAC. I have the two electrical adapters to achieve these two voltages but I need to keep the current at 1mA while the adapters are connected to two silver rods in distilled water. The resistance of the water will gradually decrease as more silver particles are added to the water so I ass u me I will need a variable resistor...? If this is correct then here are my questions: What values would the variable resistor be that I need for this application? Could I use the same resistor for both the AC and the DC circuit or would I need two different resistors? How would I connect the resistor(s) into the circuit(s)? And how can I test the circuit to make sure it's working properly? Any help with this would be greatly appreciated. Thank you.

by SilverSurfer
June 17, 2024

It seems that a constant current circuit (of 1mA) is what you look for. There are many circuits to accomplish this, check for those on the web and try it on the simulator here.

by vanderghast
June 18, 2024

Ya I get that, that's why I'm here asking for advice. If you don't have any please move along. Thank you

by SilverSurfer
July 16, 2024

1 Answer

Answer by Hedyyy

Hey! No worries. You need a variable resistor up to 30k ohms. And you can use the same for both AC and DC. Here's about connecting and testing. DC: Resistor between positive adapter terminal and one silver rod; another rod to negative. AC: Resistor between one adapter terminal and one silver rod; another rod to the other terminal. Testing: Use a multimeter to measure the current. Adjust the resistor until the current reads 1 mA. You can go for detailed information about resistors from it and it helps me a lot when I am confused: https://www.ampheo.com/blog/taking-a-closer-look-at-resistors-functions-and-applications.html Hope this helps!

ACCEPTED +1 vote
by Hedyyy
July 01, 2024

Would you suggest a potentiometer or a rheostat for this application? Also is there some way I can make this circuit automatic? Rather than to constantly have to check it and adjust the resistance is there any way to just make it automatically maintain the 1mA resistance?

by SilverSurfer
July 15, 2024

Should say to maintain the 1mA of current not resistance...

by SilverSurfer
July 15, 2024

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