Process for the relative locating of two electrical appliances

A process allows the relative locating of a first electrical appliance and a second electrical appliance by the measurement of a first number of alternations or of electrical periods by the first electrical appliance from the energizing of the said first part and up to transmission of a signal by the first electrical appliance, the measurement of a second number of alternations or of electrical periods by the second electrical appliance from the energizing of the said second part and up to receipt of a signal from the first electrical appliance and the comparison of the first number with the second number.