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.
Best Answer
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.