Microvolt DC Amplifier

ScottWang

Joined Aug 23, 2012
7,397
Don't you have some moderation to do?
You asked, so I just reply, also it is a moderation job, if you meant that when you ask then I can ignore it, I will do as your wish.

I'm also checking the other threads which I can offer the ideas to solve the problem.
 

Thread Starter

styven

Joined Jun 1, 2016
41
Good evening to all-)..I can not understand what happens to you, the man gave me a circuit which works and can become even better, and ask for help i can;t see a promplem, will be nice to help each other! ! ! I am a beginner in electronics but I try to get better through here on the site, on my country there is no solutions for some circuit...please don't irritated-))..thank you-))
 

GopherT

Joined Nov 23, 2012
8,009
The noise is likely caused by your circuit wiring - make sure the 1 meter of wire is not making a loop (circle) with a lot of area inside of the circle. Open circles like this become antennas and collect noises radio waves from nearby motors to distant radio stations. Try to keep all wires very close to each other. (The wires making this circuit AND the wires that carry the micro signal to your other circuit where the low voltage signal is used). If at least one wire is insulate in the circuit (you can twist the wires together and insure there is no open loop to act like an antenna (google "twisted pair" to learn the benefit).

Also twist the pair of wires sending your low volt signal to your other circuit.
 

Thread Starter

styven

Joined Jun 1, 2016
41
The noise is likely caused by your circuit wiring - make sure the 1 meter of wire is not making a loop (circle) with a lot of area inside of the circle. Open circles like this become antennas and collect noises radio waves from nearby motors to distant radio stations. Try to keep all wires very close to each other. (The wires making this circuit AND the wires that carry the micro signal to your other circuit where the low voltage signal is used). If at least one wire is insulate in the circuit (you can twist the wires together and insure there is no open loop to act like an antenna (google "twisted pair" to learn the benefit).

Also twist the pair of wires sending your low volt signal to your other circuit.
Ηello-) thxs again.please can you tell me what potentiometer to put in circuit? i mean potentiometer resistance; and if so how many kilo ohms?..thxs very much..
 

Thread Starter

styven

Joined Jun 1, 2016
41
A method of non-inductive winding of wire wound resistors (what you are making) similar to what Gopher T suggested can be seen in figure 2 of the images at the following link:

https://commons.wikimedia.org/wiki/File:Types_of_winding_by_Zureks.png

That will allow your resistor to not act like a loop antenna.
Thank you mister Cappels-))..i will try that you say-)..i'm trying to make my fish detector, in the sea-)my patented idea.. all fish emit microvolts-))
so i can catch many of fish with my boat-)
 

DickCappels

Joined Aug 21, 2008
10,152
And...you can use nearly any value potentiometer. A cremet or wirewound pot would give low noise.

If the pot is to be used in the actual application circuit, it should probably be somewhere after the first amplifier stage.
 

Thread Starter

styven

Joined Jun 1, 2016
41
And...you can use nearly any value potentiometer. A cremet or wirewound pot would give low noise.

If the pot is to be used in the actual application circuit, it should probably be somewhere after the first amplifier stage.
Good afternoon ser-) thxs very much for your help, it is very polite of you, you gave me nice idea, amperage I can put in this circuit?....will be nice if not a problem to draw me a plan to see your idea, If it's possible.-)) Good afternoon-)
 

GopherT

Joined Nov 23, 2012
8,009
In my first circuit, I told you to use a 10k resistor and a 60 cm piece of bare, 20-gauge wire (every 3cm from ground is a out one microVolt when using a 9V battery to power it. 60 cm from ground will give you 20 microvolts.

If you want a potentiometer instead of moving a clip somewhere along the 60cm wire...

9V +
|
1k resistor
|
10k pot linear taper (wiper connected to 1k resistor side of pot)
|
6 cm piece of wire. - tap here for various voltages (1 to 20 uV)
|
Ground (negative terminal of 9V battery)

Turn the pot to change the voltage from the tap used off of the bare copper wire. Arrange tap position to adjust voltage range when pot is turned far to one side. Then turn far to other direction to get (~10x voltage). You may find you get 10% of initial voltage if pot was connected revers of what I imagine but you will figure it out easily).
 

Thread Starter

styven

Joined Jun 1, 2016
41
In my first circuit, I told you to use a 10k resistor and a 60 cm piece of bare, 20-gauge wire (every 3cm from ground is a out one microVolt when using a 9V battery to power it. 60 cm from ground will give you 20 microvolts.

If you want a potentiometer instead of moving a clip somewhere along the 60cm wire...

9V +
|
1k resistor
|
10k pot linear taper (wiper connected to 1k resistor side of pot)


|
6 cm piece of wire. - tap here for various voltages (1 to 20 uV)
|
Ground (negative terminal of 9V battery)

Turn the pot to change the voltage from the tap used off of the bare copper wire. Arrange tap position to adjust voltage range when pot is turned far to one side. Then turn far to other direction to get (~10x voltage). You may find you get 10% of initial voltage if pot was connected revers of what I imagine but you will figure it out easily).
Thank you Fanatic-)) some draw me a plan to see-))) if it is posible-)
 

GopherT

Joined Nov 23, 2012
8,009
Thank you Fanatic-)) some draw me a plan to see-))) if it is posible-)
I did, just connect them in this order... (9V and Ground) are the two terminals of a 9V battery.

9V +
|
1k resistor
|
10k pot linear taper (wiper connected to 1k resistor side of pot)
|
6 cm piece of wire. - tap here for various voltages (1 to 20 uV)
|
Ground (negative terminal of 9V battery)
 

Thread Starter

styven

Joined Jun 1, 2016
41
A method of non-inductive winding of wire wound resistors (what you are making) similar to what Gopher T suggested can be seen in figure 2 of the images at the following link:

https://commons.wikimedia.org/wiki/File:Types_of_winding_by_Zureks.png

That will allow your resistor to not act like a loop antenna.
Good afternoon-) in figure 2 of the images, can you tell me please this material wrap the wire of what will be; and what diameter will be? thank you..
 

Thread Starter

styven

Joined Jun 1, 2016
41
Just use the same wire that Gopher T said to use in post #33. The significance of figure 2 is the way that the wire is wound.

Dear Cappel, i think you miss understood, because my english not so well-))..i was tell you, on what will wrap the wire; in a plastic tube? or wooden rod? or metal rod?
 

DickCappels

Joined Aug 21, 2008
10,152
Sorry I did not understand your question. You can wrap the wire on whatever you want, it should not make much difference. I wind the wire on 1/4 watt resistors because it is convenient (easy).
 

Thread Starter

styven

Joined Jun 1, 2016
41
Sorry I did not understand your question. You can wrap the wire on whatever you want, it should not make much difference. I wind the wire on 1/4 watt resistors because it is convenient (easy).
Thank you -)) When you come in my country we go fishing together and i;m sure we gonna catch many fish!!
and slow-slow i'm gonna tell my second patend-)
 
Top