I am just getting into soldering, developing prototypes on perf boards and microcontrollers. The current for some can be as high as 2 A. I am trying to build a drone and the BEC for one ESC is 5 V and 3 A. This may sound stupid, but how do people not get electrocuted when soldering connections that carry this current. And I don't see insulation put directly on the soldered connections or on the circuit board either.
Especially when you look at prototyping in general, there are wires hanging out everywhere and likely more than 2 A coming out of the power source. At those soldered connections, shouldn't it be practically lethal to go near it? The wires insulate the paths, but the connections should be dangerous to touch, right?
Best Answer
It’s a common misconception with beginners that a 2A power supply will force 2A through anything that touches it. This isn’t the case. Most power supplies are (more or less) constant voltage, so the resistance of the load determines what current flows. The human body has a relatively high resistance and so low voltage circuits can be handled with only tiny currents flowing. In my experience I can’t feel any current below about 1mA and for me that happens at about 100V (don’t try this at home). Even for low-voltage circuits it’s good practice not to handle circuitry when it’s powered, as it’s easy to cause shorts or disrupt sensitive signals.