Regarding the question of "Why isn't there voltage drop in a 240 volt system?"
The smart alex answer is "because no current is flowing." Only if no current is flowing can there be no voltage drop in any circuit.
All conductors, even supercondutors, have resistance and this resistance will produce a voltage drop when a current is flowing through the conductor(s).
240 volts is used over 120 (or 12 volts) because it reduces the current reguired for a fixed amount of POWER (watts). Therefore, the conductor size can then be reduced to reduce cost, size, weight or to improve flexibilty.
I would recommend no smaller than #8awg copper. This is derived by 8awg copper ampacity of 40 amps multiplied by 80% load rating to get 32 amps. Then calculating for voltage drop over this distance shows a drop of 5.9 volts or 2.5% which is negligible so not accounted for. So like i said no smaller than #8awg copper.
In the US the voltage is about 220 volts. This voltage is based upon the average voltage of the AC sine wave. It can peak as high as 240 volts or as low as 210 volts. So these different voltages are actually referring to an average 220 volt system.
From the factory it will have a 6 volt, positive ground system. However, it is popular to replace the original system with a modern 12v system.
A couple quick questions first please ... why are you using a 12 volt lamp in a 6 volt system? Have you increased the system voltage? Simply replacing a 6 volt bulb with a 12 volt bulb will cause the 12 volt bulb to burn dim ... Some systems have electrical circuits that drop (decrease) the voltage to certain units (like lights). For instance, your car is a 12 volt system (actually 14 when alternator is operating) and that 12 volts can be reduced with resistors to supply only 6 of those volts to a light ... or other device. Simply replacing with a 12 volt lamp will cause it to burn dimmer. Sorry to answer with a question but, I am just curious ...
A maximum distance of 52 feet will limit the voltage drop to 3% or less with a #12 copper conductor delivering 20 amps on a 120 volt system.
This is a voltage drop question. A #1 copper conductor will limit the voltage drop to 3% or less when supplying 100 amps for 200 feet on a 240 volt system. Or a 3/0 copper conductor will limit the voltage drop to 3% or less when supplying 100 amps for 200 feet on a 120 volt system. In your question you sis not stipulate what the working voltage is.
I would recommend no smaller than #8awg copper. This is derived by 8awg copper ampacity of 40 amps multiplied by 80% load rating to get 32 amps. Then calculating for voltage drop over this distance shows a drop of 5.9 volts or 2.5% which is negligible so not accounted for. So like i said no smaller than #8awg copper.
The voltage drop should not exceed 3% on a feeder or branch circuit.
Hook a 12 volt light to a 24 volt system and the light will burn out in seconds. You need a step-down voltage converter to do this.
Yes, the forward voltage drop of a Schottky diode is usually more than the forward voltage drop of a tunnel diode. A Schottky diode voltage drop is between approximately 0.15 to 0.45 volt. The interesting thing that makes a tunnel diode different from other diodes is its "negative resistance region" with a "peak current" around 0.06 volt and a "valley current" around 0.30 volt.
If there is nothing else in the circuit, then the voltage drop across the resistor will be the full supply voltage of 5 volts. The size of the resistor does not matter in this case - it will always be 5 volts.
In the US the voltage is about 220 volts. This voltage is based upon the average voltage of the AC sine wave. It can peak as high as 240 volts or as low as 210 volts. So these different voltages are actually referring to an average 220 volt system.
A #10 copper conductor will limit the voltage drop to 3% or less when supplying 21 amps for 150 feet on a 240 volt system.
Originally it would have been a 6 volt system.
12 volt
It is a 12 volt system.
Voltage drops need to be checked with a volt meter. Depending on where the drop is thought to be, the meter can be connected an wiring plugs to find where the drop is.