Hi, I'm a biomedical engineering student and I'm a beginner in electronics, I was trying to build a relatively simple circuit using an arduino and a EMG sensor to get analog values whenever a muscle was flexed.
I was following the powering circuit provided by the sensor's manufacturer but the sensor started burning and I don't know why. I saw a youtube video of the same circuit working perfectly fine.
Can someone tell me if I did something wrong or why this could happen?
I will atach a file from the manufacturer.

 

Show us photos of how you connected the 9V batteries.

 

Show us photos of how you connected the 9V batteries.

I dont have access to the components right now but I did do something on photoshop to show the exact way I connected the components. I also highlited the part that got burnt, again I'm a begginer, I dont know what it is.

 

If that's a conventional breadboard then +Vs, Gnd and -Vs are all shorted together.

 

That part is a capacitor. A tantalum to be exact. Can you post a photo of the actual board? The part may be installed incorrectly or power was connected incorrectly for a moment. The breadboard looks OK.

 

The thing that got burned looks like it might be an LED (Light Emitting Diode). As for the drawing of the connections, yeah, the way you've drawn it you've dead shorted the batteries. You would be better served to leave out the breadboard and just illustrate how you connected +9V, 0V, -9V.

Assuming you connected it correctly it should work. If it's burning something either it's mis-wired or the board has an issue.

[edit] Like this:

 

What are you guys looking at? The breadboard connections are fine. The top two rows are labeled minus and plus running horizontal.

 

Upon closer inspection of the traces leading to the burned component - I think @sghioto is right - it's not an LED but a polarized capacitor. IF you hooked it up wrong momentarily you might have hurt something. But none of us know exactly what you did.

 

What are you guys looking at? The breadboard connections are fine. The top two rows are labeled minus and plus running horizontal.

The V+, GND and V- (row 15) are all on the same (common) row. Besides - the picture of the board, the holes don't line up with the sockets on row 15. However, a shorted battery wouldn't harm components on the board. It looks to me - at least it's my interpretation - that @Eduardojsb used stock photos and paintbrush to illustrate his connections without realizing that the three power input pins are common on a typical breadboard.

 

He shows wires soldered from the circuit board to the breadboard. Where is the short?

 

@sghioto Row 15, pins f, g & h. However the holes on the board don't exactly line up with those holes on the breadboard.

But like I said, I think he just grabbed stock photos and edited them. I don't think he really shorted the power inputs together, even though that's the way the breadboard shows it.

 

View attachment 219702

Yeah, the image was a rushed job, the board wasn't connected to the breadboard, I can see the confusion it caused since I have placed it on top of the breadboard in the image. This image by @Tonyr1084 would be a more accurate representation. I don't believe it's an led, the board is supposed to be a knock off of this one, it's exactly the same except for the branding.

 

It's a capacitor. From the schematic it shows a 1uf tantalum rated at minimum 10 volts.

 

@Eduardojsb We would like to welcome you to AAC. As you can see - sometimes we disagree with one another. Eventually we come to consensus (most often) as to what is the best way to proceed. I'm now convinced it's not an LED. However, we can't tell what type of capacitor it is, other than it's polarized. You can look for markings on the cap and see if it was installed backwards by the manufacturer, which happens from time to time. If you can read numbers on the cap - share them with us. One of us familiar with that component will chime in and give you better direction. Ceramic caps are susceptible to fracturing from rough handling or improper soldering processes. Too quick a ramp up of temperature or cool down can cause fractures like when you drop an ice cube into a glass of water and you hear the ice pop. It's actually cracking from the sudden change in temperature. Ceramics are similar in nature. Only you're not likely to hear or detect a crack. Nevertheless, it happens.

On the off chance you momentarily wired something wrong - or when plugging the battery in you inadvertently touched the terminals backwards you might have cause an issue. But again, none of us can tell from here (wherever our homes are). It's up to you to diagnose and repair the problem.

 

It's a capacitor. From the schematic it shows a 1uf tantalum rated at minimum 10 volts.

Caps are not rated in "Minimum" voltages, rather, "Volts" meaning their Max voltage rating for normal operation. 10 volts on a 9V battery doesn't leave much room. And caps have tolerances, which could dip below the battery voltage IF the battery is fresh and new. For instance, a 9V battery can easily sit at 9.6V and a 10V cap can be ±0.2V (or more); meaning it could be damaged at voltages above 9.8V. It leaves very little room for error. But this is all guesswork on my part.

Anyway, it's breakfast time here. Peace y'all.

 

@Eduardojsb We would like to welcome you to AAC. As you can see - sometimes we disagree with one another. Eventually we come to consensus (most often) as to what is the best way to proceed. I'm now convinced it's not an LED. However, we can't tell what type of capacitor it is, other than it's polarized. You can look for markings on the cap and see if it was installed backwards by the manufacturer, which happens from time to time. If you can read numbers on the cap - share them with us. One of us familiar with that component will chime in and give you better direction. Ceramic caps are susceptible to fracturing from rough handling or improper soldering processes. Too quick a ramp up of temperature or cool down can cause fractures like when you drop an ice cube into a glass of water and you hear the ice pop. It's actually cracking from the sudden change in temperature. Ceramics are similar in nature. Only you're not likely to hear or detect a crack. Nevertheless, it happens.

On the off chance you momentarily wired something wrong - or when plugging the battery in you inadvertently touched the terminals backwards you might have cause an issue. But again, none of us can tell from here (wherever our homes are). It's up to you to diagnose and repair the problem.

Thank you! I really appreciate all the replies, I took some macro pictures of the board if you'd like to give them a look, I'm not in a hurry since I have to buy another one, I just wouldn't like to burn another board, if the error was mine. Have a good breakfast!

 

There is a difference between what you think you have and what you really have.
We will wait for actual photos.

Edit: You beat me to it. Now let's see how you wired the 9V batteries.

 

There is a difference between what you think you have and what you really have.
We will wait for actual photos.

Edit: You beat me to it. Now let's see how you wired the 9V batteries.

I didn't have the 9 volt connectors so i used electrical tape to connect the wires to the batteries, i didn't want to make the connection again but I arranged the circuit so it would be easy to see (the connections are the same, I just "spreaded" the circuit so it would be easy to see them in the photo) , the black is for -Vcc the blue is for Gnd and the red is for +Vcc.

 

If that's a conventional breadboard then +Vs, Gnd and -Vs are all shorted together.

That’s if the pads on the module are plugged into the breadboard. It’s more likely the module is just resting on the breadboard, with no connections beneath the board.

UPDATE: The picture does not show the short that’s in the drawing. Show a picture of the bottom of the module.

 

That’s if the pads on the module are plugged into the breadboard. It’s more likely the module is just resting on the breadboard, with no connections beneath the board.

UPDATE: The picture does not show the short that’s in the drawing. Show a picture of the bottom of the module.

-> The drawing wasn't true to reality, the image is how I built the circuit, in this case the board is connected to the breadboard, I don't believe I have shorted the circuit.

View attachment 219702

Yeah, the image was a rushed job, the board wasn't connected to the breadboard, I can see the confusion it caused since I have placed it on top of the breadboard in the image. This image by @Tonyr1084 would be a more accurate representation. I don't believe it's an led, the board is supposed to be a knock off of this one, it's exactly the same except for the branding.