I have a project I want to wire up on a prototype board. I know the peak voltage and current expected at each contact point. But how can I tell whether the board can handle it? If it can't then it will arc (too much voltage) or overheat (too much current) and ruin my work.
I haven't been able to find voltage or current ratings on any of these things. But the spacing and cross-section of the plating varies significantly across designs, manufacturers, etc. Here's what I have on hand:
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Strip-board: I.e., perforated board with copper traces running across the rows of holes. This is nice because I can use each row as a power bus and interconnect. Except that I don't know how much current the traces can carry. Does one commonly "proof" a strip-board by ramping current through a trace until it starts to heat, and then calculating the current capacity based on the heating rate? (Another excuse to pull out the thermocouple!) Or if I'm concerned should I just layer solder over the traces that are carrying significant current? Or avoid these altogether?
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Protoboard: Perforated board with solder pads around each hole. Some are "through-plated" (meaning the conductive plating runs through each hole to the solder pad on the other side of the board). I don't have to worry about current here because I'm making wire interconnects. But I still have to worry about voltage: Those little solder pads are very close together, and at some voltage level the electricity will arc across them. At what voltage level does one start to get concerned about arcing on this type of board? Is there a reliable way to "proof" these boards for a particular voltage level?
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Unplated perf-board: I.e., solid plastic with molded or drilled holes. When in doubt I fall back on this: It has no conductors and everything is wired so I can ensure all conducting paths are sized, spaced, and insulated for the working voltage and current. But, strangely, this is the most expensive board by unit area! (Why?)
Best Answer
Since the resistance (R) of any plated through-hole or copper trace on a proto-board is very small, no matter the voltage, not much power (P=VxI=I^2xR) will be dissipated.
What you are really asking is the power rating of your proto-board. Power is related to heat which will be the cause for damage. Most proto-boards will be fine for many applications, even high voltage. If you are working with high voltage, your concern should be for your own safety rather than the proto-board.
In conclusion, proto-board should be able to handle high currents because the resistance of a copper trace or plated through-hole is very low.
P=Voltage x Current=Current^2 x Resistance -- if resistance is small in this equation, then you have low power through the copper trace / plated through-hole
Your concern should now be focused on the power rating of the rest of the components in your circuit.
In a PCB, power ratings of a trace will depend primarily on the width and height of a trace (height in the US is usually defined in oz, ounces of copper per unit area).