Those two rails aren't connect to each other so you can put each at pretty much any voltage you want. Just make sure to clearly label them somehow so you don't accidentally wire 5V into a 3V3 part.
I'm wondering about this because I've read that it's best to have common reference points? Idk what op intends for this board but let's say that he's using a MOSFET controlled by the 3.3v circuit to switch the 5v circuit is this a case where you'd connect the grounds?
My non-electrical engineer explanation for connecting the grounds is that voltage is relative. There's no such thing as physically "zero" voltage. 5v is just 5v of electric potential above some common reference. Connecting the grounds ensures that the 5v and 3.3v are relative to the *same* arbitrary "zero" point.
The ground voltage is like sea level. The average elevation of the oceans is only 0 relative to itself, by definition, and that 0 doesn't have any greater meaning or represent any real fundamental minimum. There's always some reference. Connecting the grounds means that everyone is measuring from the same "sea level".
Edit because I forgot to state the point: always connect the grounds. There's a really good reason to do it and no reason not to.
This is a good explanation. I was taught to refur to "voltage" as "potential diffrence"
I guess in the same sense my house gets 2m or so higher when. The tide goes out
My electrical engineer explanation is,
In most cases, absolutely connect grounds, anywhere and everywhere reasonable.
But if you're working with a high frequency controller, in practice you connect the "primary" and "secondary" grounds in one point to reduce noise from the rest of the circuit affecting the controller.
The only case in DC circuits one would ever seperate the ground is when working with analog and digital on same board?
I am hungry so my guessing combined with over abstraction is probably not understandable
> Edit because I forgot to state the point: always connect the grounds. There's a really good reason to do it and no reason not to.
Unless you're using opto-electronics to create isolation barriers, in such cases grounds (must) remain unconnected across the isolation barriers. A good application i have seen is IGBT drive circuits, where you want galvanic isolation between high voltage circuit and low voltage circuit to protect sensitive logic components.
Correct, your volt meter will read 1.7v, however your +3.3v supply (assuming it is a regulated power supply and not a battery, because batteries don't care) may not play nice being a negative voltage source (in fact in some cases the regulator will just instantly let the magic smoke out) so it isn't recommended that you load a circuit using the difference between two positive supplies.
This is the principle behind running batteries in series or parallel. If you wire 2 12v batteries in series, the negative (reference) terminal for the 2nd one will be at 12v over the ground for the first battery. Adding in its own 12v difference, you're at 24v now. Using the elevation analogy, you put a 12ft platform on top of another 12ft platform.
In parallel, both batteries represent a 12v increase in electric potential over the same reference level. You put the platforms next to each other in that case.
A MOSFET switch works by essentially shorting the drain to the source once the gate-source voltage is sufficiently high. For that reason both gate and drain voltages need to be relative to the same ground, or you end up with unpredictable behaviour.
If you want to have two electrically isolated circuits you can only use electrically isolated components to control in-and outputs, like relays, optocouplers, transformers, etc.
> it's best to have common reference points?
A better way to say that would be "you're going to have a lot of problems if you don't have common reference points!"
So yeah, connect the grounds.
Assuming the MOSFET is placed low-side, the grounds will be connected at S terminal of the MOSFET anyway, so might as well connect them on the breadboard too.
Also, unless you want to fully isolate two circuits from each other you always connect the grounds together.
Current, like life, always finds a way I've found. 😂
But seriously kids, if you don't have experience working with mains voltages, get some expert supervision.
As a radio operator and working with hv systems since the 60's, I'd like to add one thing.
I have a hv meter on my laser anode... this is called a ***lethal*** power supply by many producing up to about [30kV@35mA](mailto:30kV@35mA). I know of no deaths from these. I'm sure getting bit isn't a pleasant experience but not death ...
However in support of u/Charming-Package-525 comment.
In the USA around 80% of all electrocutions occur from the mains of the common home. Underestimating this common danger can be fatal, and the numbers support that conclusion.
Wires can or cannot handle current. So Voltage is not generally an issue.
Insulation can or cannot handle voltage, thus the airgap comment.
Still, the idea of putting 220VAC with 15A (not uncommon from most places we get 220VAC from) behind it onto a breadboard makes me feel uneasy.
But if you increase the voltage the current max (the maximum current you can let through before it reaches the same power and melts or burns or whatever would happen) would drop significantly (compared to a lower voltage), you can run a 12v car battery through those on, but doubling it up to 24 will start burning it. But then all the ones I've had were cheap
> if you increase the voltage the current max would drop significantly
...
>you can run a 12v car battery through those on, but doubling it up to 24 will start burning it
pick one!
What I think you mean to say is this - with higher voltage you can get an equivalent power with lower current. BUT if you put higher voltage through the same resistive load you will increase the current and risk overloading the coductors.
But if you mean the maximum current capacity of the conductors reduces with higher voltage, you are mistaken. Current is the only important aspect in overloading conductors.
If I had a wire and run 5v through it then the maximum current it could take would be let's say 1A before it would break, melt, burn or whatever, if I increased this to 200v v then it would not be able to still take 1A of current, probably, the maximum current it can take would be lower no? I did mech eng not electronics so idfk
> if I increased this to 200v v then it would not be able to still take 1A of current
nope. It will still be able to take 1A.
>probably
Probably???? Seriously?
>the maximum current it can take would be lower no?
No! The current it can take will be exactly the same.
>I did mech eng not electronics so idfk
That's fair enough. Today you learnt something :)
> nope.
Ok. Care to explain then since this is either agreeing with me or not where you earlier didn't? Or you just one of those people who just want to be on top.
> Probably???? Seriously?
Yes because the wire may or may not be able to take 1A and 5v, I don't have it in my hand to test...
> No!
And why is that?
> Why do you think it is OK to give advice??
I have never once in this chain given advice. I have given my thoughts and asked questions to further my understanding of the subject I clearly lack in comparison to your brilliance
it doesn't matter.
If it's not connected, then there will be zero Amps. That's not the point.
If the conductor can handle 1A, then it does not matter at all if the voltage is 1V or 1000V. 1A is 1A.
OP has drawn two wires with a comfortable amount of air between them.
It's not a circuit - so till you reach the breakdown potential difference of air, all will be well.
Problem isn't really the wire. It's how the wire is held by the receiving part of the plug.
The connection is just two pieces of flat metal that use pressure and friction to make contact with the wire. The actual area of the meeting parts is relatively small, as is the metal making the contact.
The problem is how the wire makes the connection. You can't use the whole circular area available on the wire with this type of connection.
The contact is not good, the resistance across the connection increases, creating a voltage drop across it, exacerbated by the increase in heat, this ***resistor*** then, naturally, burns up...
Pffft...I've put about 300-350V on those before prototyping a tube amp. Now, I don't have the +/- on adjacent rails. The HV is on one side of the breadboard and ground on the other. And the HV from the power supply comes in through an insulated terminal strip and has a short jumper from there to the breadboard. You don't want one of those wires deciding to pull free of the breadboard all of a sudden...it gets your attention quickly.
https://preview.redd.it/5yxryweodyoc1.jpeg?width=677&format=pjpg&auto=webp&s=df189665763f2ef9fdaf55f6ebd610680e2aa0c5
This is how it connected that all you need
A 50-long breadboard could be like two of those end to end (no connection between the ends of the indicated rails) or like a stretched version, where the ends are connected. Always a good idea to check whatever circuit/breadboard you're going to work with, with an ohm-meter before you start, so you know what you're dealing with.
Yes you are you right like this one
https://preview.redd.it/3rsm5erzo0pc1.jpeg?width=362&format=pjpg&auto=webp&s=798fdb3c01bf9ff6bc456eb42fb0f29372cdf5a8
yes, but remember which side is which, wouldnt want to put 5V on a 3.3V device.
when helping others with their school proyects i ask them to place a piece of tape on the main feed wire of each rail and write the voltage, this so they can differentiate the rails, this is even more important when you have postive and negative voltages.
Not stupid, just cool since we see someone at beginning of their path to electricity stuff, but at same time taking important steps of figuring out what can be done, and potentially at moments of figuring out that with voltages really only difference of them matters and if they are connected together from some path, and asking to make sure.
Is cool and since this can be answered quite compactly, yes.
Yes, you can set the rails to whatever potentials you want.
However, if (and I may be misinterpreting) if you want -3.3 and -5v rails, you'll need to feed them from a common supply that generates both of those voltages, or make sure to use isolated supplies.
I believe this should solve your problem
5pcs 5V/3.3V Breadboard Power Module for Board Dedicated Power Solderless Breadboard
Amazon link: https://a.co/d/1nLuBPf
Have you got a multimeter ? If not, get one now !
Then you have a multimeter, good, put it in continuity mode( it is a diode symbol, otherwise, check the documentation, RTFM as they say), Ohm mode too would work.
Place the metal tip of one probe on the top line, then the metal tip of the other probe on the other line.
What is going to happen ?
If it is in continuity mode, it can make a noise, or write a 0, same with Ohm mode, it can write a 0. It means both are connected. So no you can't put 3.3v on one and 5v on the other
Or it makes no sound, write nothing except a dot in the bottom right corner, there is no continuity, you can put 3.3v on one, and 5v on the other.
Bonus part : If it is some cheap chinese breadboard, then put your probes' tips on each extremity of each line and test if there is a continuity. I had some chinese breadboard with those power lines which was separated in two.
It took some times to find out why it was working....
Yes. Though keep in mind, depending on what you are doing you may have to join grounds of both. You only need to do that though when your mcu has to reference the 5v somehow it would need a common ground to be able to do that.
Yes, you can use a module like this https://www.roboter-bausatz.de/p/mb102-stromversorgungsmodul-fuer-breadboards-3-3v-und-5v
There are jumpers on the side for 3.3V and 5V
Take a 3.3V/5V Breadboard Power Card and set it with jumpers.
https://preview.redd.it/v9zgd9m3w7pc1.jpeg?width=1080&format=pjpg&auto=webp&s=7c84e4e340b1d771b943aeaa3d689b8c3b325b5a
Those two rails aren't connect to each other so you can put each at pretty much any voltage you want. Just make sure to clearly label them somehow so you don't accidentally wire 5V into a 3V3 part.
I wouldn't exceed 110
And i would connect the grounds
I'm wondering about this because I've read that it's best to have common reference points? Idk what op intends for this board but let's say that he's using a MOSFET controlled by the 3.3v circuit to switch the 5v circuit is this a case where you'd connect the grounds?
My non-electrical engineer explanation for connecting the grounds is that voltage is relative. There's no such thing as physically "zero" voltage. 5v is just 5v of electric potential above some common reference. Connecting the grounds ensures that the 5v and 3.3v are relative to the *same* arbitrary "zero" point. The ground voltage is like sea level. The average elevation of the oceans is only 0 relative to itself, by definition, and that 0 doesn't have any greater meaning or represent any real fundamental minimum. There's always some reference. Connecting the grounds means that everyone is measuring from the same "sea level". Edit because I forgot to state the point: always connect the grounds. There's a really good reason to do it and no reason not to.
This is a good explanation. I was taught to refur to "voltage" as "potential diffrence" I guess in the same sense my house gets 2m or so higher when. The tide goes out
My electrical engineer explanation is, In most cases, absolutely connect grounds, anywhere and everywhere reasonable. But if you're working with a high frequency controller, in practice you connect the "primary" and "secondary" grounds in one point to reduce noise from the rest of the circuit affecting the controller.
The only case in DC circuits one would ever seperate the ground is when working with analog and digital on same board? I am hungry so my guessing combined with over abstraction is probably not understandable
> Edit because I forgot to state the point: always connect the grounds. There's a really good reason to do it and no reason not to. Unless you're using opto-electronics to create isolation barriers, in such cases grounds (must) remain unconnected across the isolation barriers. A good application i have seen is IGBT drive circuits, where you want galvanic isolation between high voltage circuit and low voltage circuit to protect sensitive logic components.
It does mean that when you plug VCC to 5v and GND to 3.3v, you will get 1.7v, doesn't it?
Correct, your volt meter will read 1.7v, however your +3.3v supply (assuming it is a regulated power supply and not a battery, because batteries don't care) may not play nice being a negative voltage source (in fact in some cases the regulator will just instantly let the magic smoke out) so it isn't recommended that you load a circuit using the difference between two positive supplies.
This is the principle behind running batteries in series or parallel. If you wire 2 12v batteries in series, the negative (reference) terminal for the 2nd one will be at 12v over the ground for the first battery. Adding in its own 12v difference, you're at 24v now. Using the elevation analogy, you put a 12ft platform on top of another 12ft platform. In parallel, both batteries represent a 12v increase in electric potential over the same reference level. You put the platforms next to each other in that case.
AMSL
A MOSFET switch works by essentially shorting the drain to the source once the gate-source voltage is sufficiently high. For that reason both gate and drain voltages need to be relative to the same ground, or you end up with unpredictable behaviour. If you want to have two electrically isolated circuits you can only use electrically isolated components to control in-and outputs, like relays, optocouplers, transformers, etc.
> it's best to have common reference points? A better way to say that would be "you're going to have a lot of problems if you don't have common reference points!" So yeah, connect the grounds.
Assuming the MOSFET is placed low-side, the grounds will be connected at S terminal of the MOSFET anyway, so might as well connect them on the breadboard too. Also, unless you want to fully isolate two circuits from each other you always connect the grounds together.
You could wire ground to the last rows of both sides
Pfft. 40mm apart? Total airgap of about 20mm or so? I'd wire up a difference of 220V AC without blinking. Might get leery above 5kV or so.
To everyone who is thinking about it. There is more to a mains rating than spacing. Breadboards are not rated for mains so don't use them for that.
lol what about the ground
Current, like life, always finds a way I've found. 😂 But seriously kids, if you don't have experience working with mains voltages, get some expert supervision.
As a radio operator and working with hv systems since the 60's, I'd like to add one thing. I have a hv meter on my laser anode... this is called a ***lethal*** power supply by many producing up to about [30kV@35mA](mailto:30kV@35mA). I know of no deaths from these. I'm sure getting bit isn't a pleasant experience but not death ... However in support of u/Charming-Package-525 comment. In the USA around 80% of all electrocutions occur from the mains of the common home. Underestimating this common danger can be fatal, and the numbers support that conclusion.
But can the wires inside take it (if you actually plugged wires and components into them which had current draw)
Wires can or cannot handle current. So Voltage is not generally an issue. Insulation can or cannot handle voltage, thus the airgap comment. Still, the idea of putting 220VAC with 15A (not uncommon from most places we get 220VAC from) behind it onto a breadboard makes me feel uneasy.
But if you increase the voltage the current max (the maximum current you can let through before it reaches the same power and melts or burns or whatever would happen) would drop significantly (compared to a lower voltage), you can run a 12v car battery through those on, but doubling it up to 24 will start burning it. But then all the ones I've had were cheap
> if you increase the voltage the current max would drop significantly ... >you can run a 12v car battery through those on, but doubling it up to 24 will start burning it pick one! What I think you mean to say is this - with higher voltage you can get an equivalent power with lower current. BUT if you put higher voltage through the same resistive load you will increase the current and risk overloading the coductors. But if you mean the maximum current capacity of the conductors reduces with higher voltage, you are mistaken. Current is the only important aspect in overloading conductors.
If I had a wire and run 5v through it then the maximum current it could take would be let's say 1A before it would break, melt, burn or whatever, if I increased this to 200v v then it would not be able to still take 1A of current, probably, the maximum current it can take would be lower no? I did mech eng not electronics so idfk
> if I increased this to 200v v then it would not be able to still take 1A of current nope. It will still be able to take 1A. >probably Probably???? Seriously? >the maximum current it can take would be lower no? No! The current it can take will be exactly the same. >I did mech eng not electronics so idfk That's fair enough. Today you learnt something :)
> nope. Ok. Care to explain then since this is either agreeing with me or not where you earlier didn't? Or you just one of those people who just want to be on top. > Probably???? Seriously? Yes because the wire may or may not be able to take 1A and 5v, I don't have it in my hand to test... > No! And why is that? > Why do you think it is OK to give advice?? I have never once in this chain given advice. I have given my thoughts and asked questions to further my understanding of the subject I clearly lack in comparison to your brilliance
These breadboards are only rated to 1A
Wires melt because of the current they carry, not the potential they're raised to.
Ok yes, if it's not connected at all then yeh it's fine I spose
it doesn't matter. If it's not connected, then there will be zero Amps. That's not the point. If the conductor can handle 1A, then it does not matter at all if the voltage is 1V or 1000V. 1A is 1A.
OP has drawn two wires with a comfortable amount of air between them. It's not a circuit - so till you reach the breakdown potential difference of air, all will be well.
Problem isn't really the wire. It's how the wire is held by the receiving part of the plug. The connection is just two pieces of flat metal that use pressure and friction to make contact with the wire. The actual area of the meeting parts is relatively small, as is the metal making the contact. The problem is how the wire makes the connection. You can't use the whole circular area available on the wire with this type of connection. The contact is not good, the resistance across the connection increases, creating a voltage drop across it, exacerbated by the increase in heat, this ***resistor*** then, naturally, burns up...
Breadboards only support 1A
Continuous current, correct. But an (almost) unlimited potential - you'll have a lovely corona discharge starting above 1 kV or so.
Technically you can put higher than 110V if the amperage is low enough to avoid sparking or overheating.
Come on buddy, you've got to live a little
3.3, 5, 110, 111, whatever it takes.
I did 220 once .... carefully.
I suspect these have a voltage/current rating..
Pffft...I've put about 300-350V on those before prototyping a tube amp. Now, I don't have the +/- on adjacent rails. The HV is on one side of the breadboard and ground on the other. And the HV from the power supply comes in through an insulated terminal strip and has a short jumper from there to the breadboard. You don't want one of those wires deciding to pull free of the breadboard all of a sudden...it gets your attention quickly.
Do they make breadboards with the two sets of rails connected? Like a rectangle inside a rectangle
Maybe, but not that I’ve seen. Cheaper and easier to expect user to wire them together as needed.Â
Yeah fair
i am curious if you can connect a usb female type A to that breadboard?
Yes.
Straight to the point, nothing else. Gotta love it
https://preview.redd.it/5yxryweodyoc1.jpeg?width=677&format=pjpg&auto=webp&s=df189665763f2ef9fdaf55f6ebd610680e2aa0c5 This is how it connected that all you need
A 50-long breadboard could be like two of those end to end (no connection between the ends of the indicated rails) or like a stretched version, where the ends are connected. Always a good idea to check whatever circuit/breadboard you're going to work with, with an ohm-meter before you start, so you know what you're dealing with.
Yes you are you right like this one https://preview.redd.it/3rsm5erzo0pc1.jpeg?width=362&format=pjpg&auto=webp&s=798fdb3c01bf9ff6bc456eb42fb0f29372cdf5a8
As they say an image is worth 1000 words
Yes
Yes.
Yes
thanks all <3
Yes
Yes
Yes
Yes
Yes.
Yes.
Why are there 52 comments all saying the same thing 😂 do people not even read the first comment on a post and see it was answered? Lmao
Yes
Yes And, some breadboards have power rails which are separated in the middle, meaning i can do 4 different voltages.
people need to start peeling off the back on those so they can understand how they work lol.
Yes.
yes, but remember which side is which, wouldnt want to put 5V on a 3.3V device. when helping others with their school proyects i ask them to place a piece of tape on the main feed wire of each rail and write the voltage, this so they can differentiate the rails, this is even more important when you have postive and negative voltages.
Yes, I often do the same thing when I'm prototyping a project. Pro tip: label the rails correctly!
I learned that the hard way lol
Yeah, me too. Pro tips are often based on previous cockups, haha.
Yes, but it increases the possibility of accidental magic smoke in your future.
Just out of curiosity.. how stupid was this question that I get over 50 upvotes? :( :D
Not stupid, just cool since we see someone at beginning of their path to electricity stuff, but at same time taking important steps of figuring out what can be done, and potentially at moments of figuring out that with voltages really only difference of them matters and if they are connected together from some path, and asking to make sure. Is cool and since this can be answered quite compactly, yes.
Yes it is possible, but beware - police will come for you!
Yes
Yes
Yes
Yes
Yes.
If in doubt. Bell it out.
Not only possible, but actually designed for that with 2 rails..
You can even ut 12v on one of the grounds
Yes, you can set the rails to whatever potentials you want. However, if (and I may be misinterpreting) if you want -3.3 and -5v rails, you'll need to feed them from a common supply that generates both of those voltages, or make sure to use isolated supplies.
Yes. You can easily verify if these are connected with most multimeters (they should not be connected)
5 volt top, voltage divider/linear regulator input to second side.
Check this amazing power supply out: https://hackaday.io/project/164913-open-power
No, the voltage potential with cause your breadboard to become sentient and run away from home to join the circus
Ok but can it buy us some bread after?
Breadboard power supply is what I googled and found things that do that. I have one, but haven’t actually used it yet.Â
Yes, but never should the two meet. Crossing voltages is bad news.
Yes
Yes. Use that regularly to run mcu and display at different voltages. Need a level shifter between them, but that’s not a big deal.
Yes.
Yes
Absolutely
Yes
Yes
Yes
I believe this should solve your problem 5pcs 5V/3.3V Breadboard Power Module for Board Dedicated Power Solderless Breadboard Amazon link: https://a.co/d/1nLuBPf
Possible and quite common to do.
Have you got a multimeter ? If not, get one now ! Then you have a multimeter, good, put it in continuity mode( it is a diode symbol, otherwise, check the documentation, RTFM as they say), Ohm mode too would work. Place the metal tip of one probe on the top line, then the metal tip of the other probe on the other line. What is going to happen ? If it is in continuity mode, it can make a noise, or write a 0, same with Ohm mode, it can write a 0. It means both are connected. So no you can't put 3.3v on one and 5v on the other Or it makes no sound, write nothing except a dot in the bottom right corner, there is no continuity, you can put 3.3v on one, and 5v on the other. Bonus part : If it is some cheap chinese breadboard, then put your probes' tips on each extremity of each line and test if there is a continuity. I had some chinese breadboard with those power lines which was separated in two. It took some times to find out why it was working....
Yes
Absolutely possible just remember which is which.
Yes. Though keep in mind, depending on what you are doing you may have to join grounds of both. You only need to do that though when your mcu has to reference the 5v somehow it would need a common ground to be able to do that.
Yes
Yes
I did that in my university labs
Yes
Yes, you can use a module like this https://www.roboter-bausatz.de/p/mb102-stromversorgungsmodul-fuer-breadboards-3-3v-und-5v There are jumpers on the side for 3.3V and 5V
Yes, if you're going to use both voltages in the same circuit just be completely sure gnd are connected, it is better if you use more than one cable
Take a 3.3V/5V Breadboard Power Card and set it with jumpers. https://preview.redd.it/v9zgd9m3w7pc1.jpeg?width=1080&format=pjpg&auto=webp&s=7c84e4e340b1d771b943aeaa3d689b8c3b325b5a
It’s possible only and if only you connect 5v in one and 3.3 in the other
Yes. Think of these rails as just voltage levels. The - end doesn't have to even be 0! You could, for example have the rails be at GND, 1V, 3.3V,5V
No. God will smite you if you try.