Calculating heat loss and conduction through a wire

AI Thread Summary
The discussion focuses on calculating the current through copper wires when using a 9V battery to melt solder paste. The user is concerned about the high current calculation, which exceeds 1000 A, and questions its realism due to heat losses and wire conduction. It is clarified that the internal resistance of the battery, which ranges from 1.7Ω to 2.8Ω, is the primary factor limiting the current, rather than the resistance of the solder paste or wires. A 9V battery can deliver a short circuit current of approximately 5A, while larger batteries, like a 12V car battery, can provide much higher currents but pose significant safety risks. Understanding these resistances is crucial for accurate current calculations in their project.
electricnov
Messages
3
Reaction score
0
I'm creating a project where I am attempting to melt solder paste using the current running through two copper wires, in a kind of lap joint. I'm trying to figure out how much current would actually be going through the wires if I use a 9V battery. I'm not sure where to take into account heat losses and the conduction of heat through the wire.
I'm new to circuits and all things electrical, so any help would be great! thanks!
 
Engineering news on Phys.org
Thank you for the post. I understand that part. My question is about the current. The resistivity of solder paste is very low and so the current I calculate is very high (over 1000 A). This isn't actually a realistic number right? Is there some kind of loss in practice?
 
The highest resistance in your circuit will be the internal resistance of the battery. Small 9V batteries won't deliver more than a few amps of current and only for a short time.

On the other hand a 12V car battery could deliver 500A or more, but DON'T TRY THAT EXPERMENT. You run a serious risk of getting burned, and also the battery may release explosive gas which could be ignited by a spark when you try to disconnect the circuit. (You willl quite likely wreck the car battery as well, but that's a minor problem compared with the safety issues).
 
The 9V battery short circuit current is close to 5A at the beginning.
The 9V battery internal resistance is between 1.7Ω to 2.8Ω.
 
So, in calculating the current, I take into account the resistance of the battery? and not the solder paste or the wire? Is that just because it is negligible in comparison with the battery?
 
electricnov said:
So, in calculating the current, I take into account the resistance of the battery? and not the solder paste or the wire? Is that just because it is negligible in comparison with the battery?
Yes, the battery internal resistance is the main factor limiting the short circuit current.
At least for 9V battery.
 

Similar threads

Can Graphene Wire Coils Replace Copper in Generators?
Replies
15
Views
2K
Calculation of induction heating setup power consumption
Replies
5
Views
2K
Copper Losses in an Electric Generator
Replies
5
Views
3K
How to estimate the heating of a wire
Replies
5
Views
5K
Calculating the Power Dissipation of a Wire
Replies
23
Views
7K
Electric conductivity loss due to weather on electric fence wire?
Replies
8
Views
3K
Surface oxidation of aluminum alloy and electrical continuity
Replies
16
Views
4K
Building a Safe and Efficient Induction Heater Circuit: Tips and Tricks
Replies
7
Views
6K
How to replicate electric blanket? (Project)
Replies
20
Views
7K
Nichrome Wire foam cutter/heater
Replies
8
Views
6K

Hot Threads

Recent Insights

Back
Top