Magnetic receivers use the electromagnetic principle to receive and analyze signals. An electromagnetic principle can be defined as electric currents running along a wire that produce magnetic forces and rotating magnets around a wire produce electricity. The simplest example of a magnetic receiver is the telephone. A magnetic receiver in a telephone converts the analog electrical signals back into acoustical energy. Signal receivers are used in television transmissions, and are used to receive cable and satellite transmissions. A signal receiver device receives broadcast signals and detects rating or category codes therein. The signal receiver compares the detected code to a setting set in the device. If the comparison indicates that the incoming signal has a rating greater than that set or is of an undesired category the broadcast signal is blocked or an alert is given. Magnetic receivers and signal receivers may be tamper-resistant in certain devices to prevent disabling of the device.
Magnetic receivers are generally a small triad of electromagnetic coils, enclosed in a plastic shell that detects the magnetic fields emitted by a transmitter. Magnetic receivers emit electromagnetic energy that can be detected with electromagnetic detectors. An electromagnetic detector is used to detect magnetic fields. When electrons oscillate, their electric and magnetic fields change together, forming an electromagnetic wave. This movement can come from atoms being heated and thus moving about rapidly or from alternating current electricity. The opposite effect occurs when an electromagnetic wave hits matter. In such a case, it could cause atoms to vibrate, creating heat, or it can cause electrons to oscillate, depending on the wavelength of the radiation. A handheld electromagnetic detector can consist of a sensor with associated electronics mounted on the bottom of a lightweight plate attached to a handheld wand, a visual LCD display mounted in a frontal viewing position, a 12V DC battery pack which also acts as a counterbalance, and an X-Y-Z coordinator for tracking. An electromagnetic test is nondestructive testing performed on an electromagnetic device in which electromagnetic energy with frequencies less than that of light is used to discover information about the quality of the material in the test object. Magnetic receivers are designed and manufactured to meet most industry specifications.
Magnetic receivers are used in many applications. Magnetic receivers are used in the communications field as well as nuclear magnetic resonance, spectroscopy, and micro-imaging. Electromagnetic detectors are a crucial tool in the detection of landmines and other explosive devices. Magnetic receivers should adhere to the Institute of Electrical and Electronics Engineers (IEEE) standards.