Product Description

Auto transformers Auto transformers are a special type of power transformers with only one winding. A portion of this single coil serves as part of both the primary and secondary winding. Deferent voltages are obtained by tapping or connecting at deferent points along the winding, which as at least three taps where electrical connections are made. Both the voltage source and the electrical load are connected to two taps. The tap at the end of the winding serves as a common connection to both circuits. Typically auto transformers are used in low power applications and to interconnect systems operating at deferent voltage classes they may be water proof, rated for out door use or equipped with enclosures. Product specification auto transformer include:- 1) Rated Power, 2) Primary Voltage (at no-load), 3) Secondary Voltage (at no-load), 4) Voltage Tapping Range, 5) Secondary Current Rating, 6) Operating frequency, 7) Vector Group, 8) Impedance, 9) Ambient Temperature, *0) With or Without Enclosure. There are three basic types of products: - A) single phase B) Three phase (polyphase) C) variable. Single phase transformers, as there name suggests, operate with single phase voltage. Three phase autotransformers are polyphase devices in which the primary windings are connected together and the three secondary winding are connector together. Variable auto transformers or variacs have a sliding tap. Core Type, Cooling Method, Output Voltage and mounting or factor are additional product specification to consider when selecting Three Phase Transformers. Core Types are listed as EI laminated, Trips, Toroidal, Rectangle and other. There are four choices for cooling method: Dry Type, Natural Air Cooled, Forced Air cooled, Oil Cooled, and other. There are a variety of from factors or mounting styles to choose from. Choices for three phase transformers include Chassis Mount, H-Frame, Modular Jack, Pad Mounted, Printed Circuit Board (PCB), and Pole Mounted. Auto transformers differ in terms of winding turns and out put voltage, with step-up transformers the secondary voltage is large then the primary voltage. With step-down devices, the secondary voltage is smaller then the primary voltage. Variacs or variable autotransformers (auto formers) have a setting for changing the tum ratio as needed. One-to-one devices have a tum ratio of 1:1, or near 1:1. There are two choices for output voltage type: alternating current (AC) and direct currant (DC). Typically, the AC waveform output voltage values for autotransformers are expressed as root mean square (RMS) values.