A Transformer is a device that transfers electrical energy from one circuit to another through inductively coupled electrical conductors. A changing current in the first circuit (the primary) creates a changing magnetic field; in turn, this magnetic field induces a changing voltage in the second circuit (the secondary). By adding a load to the secondary circuit, one can make current flow in the transformer, thus transferring energy from one circuit to the other. A key application of transformers is to reduce the current before transmitting electrical energy over long distances through wires. Most wires have resistance and so dissipate electrical energy at a rate proportional to the square of the current through the wire. By transforming electrical power to a high-voltage (and therefore low-current) form for transmission and back again afterwards, transformers enable economic transmission of power over long distances. Consequently, transformers have shaped the electricity supply industry, permitting generation to be located remotely from points of demand. Transformers are used extensively in consumer electronic products to step down the supply voltage to a level suitable for the low voltage circuits they contain. In these kind of applications the transformer may also act as a key safety component that electrically isolates the end user from direct contact with the potentially lethal supply voltage.

Identification. A surgical sponge scale is a nonelectrically powered device used to weigh surgical sponges that have been used to absorb blood during surgery so that, by comparison with the known dry weight of the sponges, an estimate may be made of the blood lost by the patient during surgery.

Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter, subject to the limitations in 880.9. The device also is exempt from the current good manufacturing practice requirements of the quality system regulation in part 820 of this chapter, with the exception of 820.180, with respect to general requirements concerning records, and 820.198, with respect to complaint files.

Digital baby scales represent maximum safety and accuracy when weighing babies. This electronic baby scale is specially designed for measuring the weight of baby with features of high accuracy, advanced technology and long-time use.

Electrosonograph records the frequency and amplitude of the noise produced as well as the position in the opening/closing at which sound is produced. These microphones measure joint sounds and where they occur as you open & close the mouth.

Emergency audio call system is designed for use primarily in retirement centers. It includes an emergency call unit having a memory for storing a plurality of telephone numbers to be called and an emergency message. These are utilized mostly in hospitals and nursing homes. This enables a patient to summon for help by activating an emergency call station by their bed. Voice communication allows communication between patient and nurse station.

Emergency blanket is a compact, lightweight blanket. It is made of super insulating material that can help prevent hypothermia. These blankets weigh only about 2 ounces and fold small enough to fit in a pocket. It reflects body heat back to body.