Voltage drop

In <a href="/facts/Electronics/E4JhgISq">electronics</a>, voltage drop is the decrease of <a href="/facts/Electric_potential/Nmqm6hm5">electric potential</a> along the path of a <a href="/facts/Electric_current/Dc1xdnUX">current</a> flowing in a <a href="/facts/Electrical_network/zt94kTW0">circuit</a>. <a href="/facts/Voltage/EN2po6N2">Voltage</a> drops in the <a href="/facts/Internal_resistance/2PexRRay">internal resistance</a> of the <a href="/facts/Power_supply/4A8zBRHn">source</a>, across <a href="/facts/Electrical_conductor/BSuyupLP">conductors</a>, across <a href="/facts/Electrical_contact/eELyUxrd">contacts</a>, and across <a href="/facts/Electrical_connector/rJh0cHs6">connectors</a> are undesirable because some of the energy supplied is <a href="/facts/Dissipation/C134STy1">dissipated</a>. The voltage drop across the <a href="/facts/Electrical_load/IX0XBAqB">load</a> is proportional to the <a href="/facts/Electric_power/w61ID9yQ">power</a> available to be converted in that load to some other useful form of energy. 
For example, an electric <a href="/facts/Space_heater/sQhSDcf0">space heater</a> may have a resistance of 10 <a href="/facts/Ohm/QNVrlGjw">ohms</a>, and the wires that supply it may have a resistance of 0.2 ohms, about 2% of the total circuit resistance. This means that approximately 2% of the supplied voltage is lost in the wire itself. An excessive voltage drop may result in the unsatisfactory performance of the space heater and the overheating of the wires and connections.
National and local <a href="/facts/Electrical_code/xxjQVK0R">electrical codes</a> may set guidelines for the maximum voltage drop allowed in <a href="/facts/Electrical_wiring/Ibfa7Eq7">electrical wiring</a> to ensure efficiency of distribution and proper operation of electrical equipment. The maximum permitted voltage drop varies from one country to another. In electronic design and <a href="/facts/Power_transmission/YFTg5l6t">power transmission</a>, various techniques are employed to compensate for the effect of voltage drop on long circuits or where voltage levels must be accurately maintained. The simplest way to reduce voltage drop is to increase the diameter of the conductor between the source and the load, which lowers the overall resistance. In <a href="/facts/Power_distribution/F5NfTeWP">power distribution</a> systems, a given amount of power can be transmitted with less voltage drop if a higher voltage is used. More sophisticated techniques use active elements to compensate for excessive voltage drop.

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Voltage drop