New answers tagged

1

You could use almost any kind of through-hole soldered connector mounted on the bottom with pins upwards, soldered on the top. Such as any one of the hundreds of kinds: Image from Duckduckgo If you really want to solder it, consider an IDC ribbon cable header, which crimps onto the cable and presents pins to the PCB (from underneath) which you solder (on ...


0

Mmmpf. Somehow I missed that you want to make a single layer board. The following runs into a double sided board. Sorry. I'll leave it here in case somebody else finds it useful. Design your single layer board and use a single pin connector at each point in the schematic where you need to connect a wire. When you place it in the layout, use a through ...


3

There is a product from Molex that might be designed specifically four your use case. It is called: Bottom-Entry Lite-Trap SMT Wire-to-Board Connector And it looks like that: There will still be machining to do on the PCB, in order to allow the connector housing through, but the result will be solder-free and super clean looking, I think. But for 20 ...


0

Raspberry Pi GPIO should register 3.3V for a logic 1. Assuming the impedence looking into Pin22 GPIO 25 is infinite, Pin 12's voltage is a voltage divider. 1/11 or 1K/(1K+10K) of 5V = 5/11 = 0.45V << 3.3V (yikes!). Choose R2 (pull down resistor) that provides 3.3 volts and not 5/11 = 0.45V Seek: R1/(R1+R2) = 2/3 If we keep R2 = 10K, then change ...


-1

Since the current through this circuit is the same, we can present the problem both in terms of resistances and in terms of voltages. If the resistances are geometrically linear, we can present it even in terms of lenghts: Rl/RL = Vl/VL = l/L or RL/(Rl + RL) = Vl/(Vl + VL) = l/(l + L)


10

\$V=IR\$ isn't just something you apply to the circuit as a whole. \$V\$ also isn't necessarily the voltage you're driving through the circuit. \$V=IR\$ is also how you calculate the voltage drop across a given resistance. If our load is relatively high resistance and as a result, our current \$I\$ is small, that means the actual impact (voltage dropped) ...


2

As for the second idea, your assumption that V is beeing constant is wrong. V is not constant but it is kind of "produced" by I and R. So if the current through a wire is low and resistance is not too high, then the voltage drop V across this wire will also be low. V might be (thought of) constant for a batteries or other voltage sources, but in fact, all ...


8

The ability to shrink is usefull to fix it into place. For example if you solder 2 wires together you have a part where you remove the insulation to solder the wires. Heatshrink tubing can be placed over the solder joint and heated up. If the correct size tubing is chosen it will shrink enough that you can't move the tubing from the solder joint, thus "...


3

Absolutely not, no way, no how. Both the NEC (or your local electrical code, surely derived from NEC) and UL's White Book are very clear on what is safe for electrical work and what is not. NEC 110.2. Equipment must be approved. That means some authority like UL must certify it as safe. Next paragraph, NEC 110.3(B), Equipment must be used according to ...


6

From the link provided: IMPORTANT: DO NOT use for building/household 110/220 V ac wiring There is no datasheet either. Every component has a voltage rating beyond which there can be no reliable operation or characteristics . They can breakdown in different ways at higher voltage. Please do not use for safety reasons.


2

It might be off, it might not, why bother? The Drude model of conductivity is so inaccurate, so lacking in good correlation with reality, that it's really a waste of time to get pedantic about exactly what the drift velocity is. Just let the big, or small, numbers wash over you in a hand waving way, 'coo, I didn't realise average electron drift velocity was ...


0

I'll just add a few additional examples of why this is important and actually taken into consideration pretty much all the time. The first is not really electronics, but actually very high-voltage electricity. There's a reason long-distance (and most importantly high power) electricity transmission networks (you know, the big huge towers carrying cables) ...


0

There are a lot of good answers here. Practical cases where wire length and xsectional area are important: Measuring very small resistances. Using 4-wire measurements removes the resistance of the wires from the measurement. When connecting solar cells and solar panels together, the resistance of the connecting tinned copper ribbons affects the ...


4

Real devices have non-trivial sample variations in their properties. Circuit designers must allow for these variations. Sample variation can overwhelm certain other considerations. Consider that commercially available resistors are offered in various tolerance ranges; 10% being one of them. If a designer chooses to employ a 1k Ohm 10% resistor in a given ...


2

You can add two more ingenious techniques for eliminating the wire resistance to the physical idea of superconductivity and circuit idea of remote sensing above. I have illustrated the written with two pictures from another source dedicated to the same subject. They show the voltage distribution along a real conductor with line resistance Rl. The first idea ...


6

How common is it to consider the resistance of a wire? Is the resistance of a wire an important consideration when doing electronics work? Does this resistance need to be factored into calculations, as would other components (such as resistors)? I see many good answers here but I want to add a few extra points not mentioned yet. Ideal circuits do not exist ...


58

Sometimes, a wire is negligible in terms of its resistance. Other times, impacts of the resistance of a wire can become significant. I'll first show the resistance of a wire, and how you can ignore it in most cases, and then show examples when its impact is significant, and finally a few applications. The Resistance of a Wire Ideally, the formula of the ...


3

In our product range we connect devices running over distances of upto 300 meters. Hence, when calculating the minimum vorlage requirement compliance for a power receiving device at the remote end. we have established a definition for the cable and we also consider it in our calculations. When there is a need for higher wattage or longer distances, the cable ...


9

The resistance of a wire, (or more generally, the interconnect) comes into play at all scales of electrical design. In commercial power distribution systems, conductor resistance causes some of the electrical power to be lost as heat. So the less resistance, the less power is loss. This is why in some limited application superconductors are being ...


7

The text is a little bit sloppy but it is basically correct. There are two concerns when choosing a wire size. First is heating in the wire. If the wire will become hot and cause a burn hazard (or fire hazard) then you must use a larger wire. For further reading use the search term "ampacity table." Second is voltage drop. This is more likely to be a ...


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