I have some single core wires normally used in simple breadboard circuits to handle 5V.

I have built a power supply circuit on a perfboard, with a standard transformer + capacitor + 7805 build. Can I use a single core wire to make the connection on the perfboard?

The 5V devices I am connecting to this will not draw more than 300 mA. The transformer I am using is rated at 300 mA.

  • \$\begingroup\$ Can you tell us exactly what kind of wires you have? \$\endgroup\$
    – Christoph
    Mar 11, 2013 at 13:06

2 Answers 2


Concerning the connection of mains to the transformer:

NO! As Christoph says, there is nothing wrong with single core (just the opposite), but the isolation of +5VDC wires is intended for +5VDC.

If you keep the wires in the air, far apart from anything, there will, probably, be no problem. However, if they touch anything (including yourself), there is significant chance of electrical shock.

Concerning the connection from the transformer onward:

Probably no problem, if the transformer output voltage is no larger than 24V.

  • \$\begingroup\$ You are right, my answer should have been clearer regarding insulation. \$\endgroup\$
    – Christoph
    Mar 11, 2013 at 13:05
  • \$\begingroup\$ The worst thing is, they will appear to work (as the current draw will be small), but later, when two wires touch or insulation is somewhat damaged - boom - sparks and soot. Can also happen with touching resistors. \$\endgroup\$
    – Vorac
    Mar 11, 2013 at 13:09
  • \$\begingroup\$ Well, depends on the exact type of wire. Let's see what the OP can tell us about that. \$\endgroup\$
    – Christoph
    Mar 11, 2013 at 13:13

If you look around your house (in the walls, in fact), you will probably find many single core mains wires. They are reliable when they are fixed in their place, unlike cables.

If the wires can handle the current (what diameter are they?) and have proper insulation (thick enough for mains voltage), you can use them. The fact that they are single core helps prevent shortcuts due do small "stray wires". Make sure that you keep them at a minimum distance of about 2 mm. Use different colors for different lines. Keep them seperate from low-voltage/data wires.


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