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voltage and current regulator Symptoms, Causes and Cures of Radio Interference

by:KEBO      2019-10-25

You have been out for hours and are close to your destination.It's late now and you're not familiar with the upcoming port, so you can safely get into the port with your navigation equipment.According to your chart draftsman, you should be right at the top of the external buoy, but you can't see it.You look around, but it's not there.The radar tells you that this buoy is about half.A mile west of you.How is it possible?
Take out the paper chart of the area and you compare it to your GPS and find out that you are indeed a halfA mile from the stadiumGive up the GPS and the drawing machine and you can take you to the buoy and port with the radar.
What you have just experienced is most likely the result of some electrical system interference on board, resulting in inaccurate GPS positioning.The effects of interference can range from static noise and other noise on radio receivers and entertainment systems to incorrect readings on faulty electronic navigation systems and instruments.
Interference is any unwanted electrical noise source that interferes with the normal operation of electrical or electronic circuits and is generally classified as RF interference (RFI), emc interference (EMI) it can also be an electronic pulse (EMP ).The RFI is an interference that occurs in a specific frequency range ranging from 10 kHz (kHz) to 300 MHz (MHz), while EMI covers a wider range.High instantaneous pulseThe intensity of electric energy burst.These pulses can occur in many ways, such as when the voltage on the inductive load changes rapidly.An example is the pulse generated by the ignition coil in gasoline.powered engine.This pulse also occurs when the motor is activated, or when the electrical contact is manufactured or disconnected.EMP can do quite a bit of damage, especially in today's electronics.EMI is essentially interference or noise, superimposed on the power supply or data or signal line as interference or voltage transient.This interference is then processed with good data to corrupt or downgrade the processed data.There are many potential EMI sources on board, such as electric motors, winches, anchors, pumps and anything else that could cause sparks.Outside the ship, there are also sources such as lightning and other nearby ships.However, the main source is the engine of the vessel and its auxiliary system.So, how to isolate the source of EMI?
Radiation EMI is generated by voltage and current in electrical and electronic equipment.It is received or transmitted by the wire carrying the signal and power.It may also be caused by the manufacture and disconnection of electrical contacts.The best solution is to identify the source device and correct the situation there.If this is not possible then you have to use separation, shield or filter.Shielding means closing the source or the affected equipment (or both) in a metal enclosure connected to the ship's land.The radiation energy is absorbed and transmitted to the ground by shielding.If the equipment has a metal cabinet, the Cabinet is simply grounded.Otherwise, the device must be enclosed in a wire mesh or foil.In the case of a wire, the conductor can be replaced by a shielded cable.A filter is a circuit that allows some frequencies to pass through when other frequencies are blocked or diverted to the ground.Filters generally use capacitors, inductors, or both depending on their design and intended use.Your local marine electronics dealer offers a variety of filters.Portable AM radio is a very useful and cheap tool to help locate EMI sources.Choose one with a headphone jack so you can hear it in a noisy place, like near the engine.You can use the radio to determine the cause of EMI by listening to the sound generated by the offending device.Just get it close to the suspicious device and listen to the crackles, hisses, etc.Turn off the device when you hear the noise and see if the noise is gone.If so, congrats!You have found the culprit.The sources most likely to generate EMI on board are AC generators, voltage regulators, and gasoline engines, spark plug wires, ignition coils, dispensers, etc.Other possible sources are Motors, switches and other electronic devices.The alternator produces a whooping or whistling sound in a radio receiver that varies with the engine speed and output current.When the battery is fully charged, it is not so obvious.Removing the AC generator belt and running the engine helps determine if this is the cause of EMI.There are filters specifically designed for the alternator, as well as most other devices that cause EMI.The noise generated by the voltage regulator sounds almost the same as the AC generator, but it only changes with the output of the AC generator, not with the engine speed.The ignition circuit of the gasoline engine is a common source of EMI.At low engine speed, it starts with a slow tick or burst sound that turns lowAs the engine speed increases, it makes a harsh sound.It may be suspected that it is Coil, dispenser and/or spark plug and plug wires.A low-It is recommended to connect the through filter in series with the wire to the ignition switch.Also, the high-The tension line from the coil to the dispenser cover, as well as the spark plug and the plug line should be suppressed-Type component.Starting the motor is another common source of EMI.These motors generate pulses when starting.Then, the pulse is picked up through the harness of the ship and transmitted to the electronic device.These voltage spikes can cause great damage to electronic devices.There are specially designed products that can not only protect the electronics, but also provide a stable DC voltage source to prevent the equipment from crashing.Due to poor contact between the brush and the slip ring or the diverter, the DC motor is the main source of EMI.This creates an arc, which in turn produces EMI.The first step is proper maintenance.Keep the brush in good condition and clean the slip ring and the switch.Filtering is necessary if this does not solve the problem.Other sources of EMI caused by ground or joint contact failure.These can usually be found on metal cabinets, motor housing and other electrical equipment housing.If the contact of the grounding brush is dirty or worn out, the pillar shaft is another possible source.If the problem persists, the grounding and connection system of the vessel should be thoroughly checked.The ground wire and ground wire should be at least heavier as the power supply line of the equipment.It should be tin-plated copper twisted wire.Contacts must be clean and tightly assembled.A good grounding and connection system is essential to prevent damage to electrical impulses.Please replace the conductor and/or re-make the connection if you have any questions.Sometimes, you will still be plagued by EMI despite your best efforts.It may be that the equipment is faulty, improperly installed or of low quality.In this case, the equipment may have to be repaired or replaced.A qualified technician will be the best able to help you here.So, the next time you have a strange problem with your electronics, look for sources of interference.If you find and eliminate interference, your problem is likely to be resolved.
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