One hertz is one cycle per second, meaning repeating cycle as an event. For example, hertz is applied physics measuring the number of times for a second wave (either acoustic or electromagnetic) is repeated or can be applied, among other uses, to ocean waves that reach the Beach vibrations per second or a solid. The quantity that measures the frequency hertz is called,in this regard, the inverse of the period. One hertz is an oscillation frequency of suffering a particle over a period of one second.

VDC would be the abbreviation for Volt Direct Current which translated would volts direct current. The idea of ??this type is unidirectional current to the load. Direct current is normally produced by batteries, thermocouples, solar cells and a dynamo electric machine type. The direct current can flow in conductors such as wires, but may also flow through semiconductors, insulators ... In the image: 1 - current per pulse 2 - Direct Current (DC) 3 - Alternating Current (AC) 4 - Variable Current

The EAS RF (Electronic Article Surveillance) monitoring system or electronic surveillance system for items is a very common and effective method to guarantee the security of your business and minimize the risk of theft or theft.

This type of systems can be implemented in rigid or flexible systems, among which we can find the most common types.

Remember that depending on their type they can work in a frequencyto different.

• Magnetic label
• Acustomagnetic label, work on 58 MHz frequency.
• Radio frequency (RF) label, works in the frequency of 7.4-8.8 MHz, although they usually work in the 8.2 MHz, it is the most used in stores and businesses.
• Microwave label, they work in the frequency 2450 Mhz.

As mentioned, the most common security labels are RF, since it can befind in different formats, among them the most common:

• Rigid RF tag: Rigid security tags ideal for textile items, such as shirts, pants, coats etc ...
  This type of labels consist of a base of rigid plastic material connected to a pin type pin. Once united, it is only possible to uncouple them with a magnetic system.
• RF label with cable: Semi security labelsThanks to its steel cable, they can be adapted to other types of products, such as wine bottles, bicycles, machinery on display, etc. The decoupling system is by magnetic system as are the rigid ones.
• Soft RF label: Flexible security label, normally used in all types of products such as clothing, footwear, books, tools, food, etc ... thanks to its adhesive system. The system of deactIivation is through an RF deactivator. This deactivation system emits a very high RF impulse that manages to burn the internal diode, leaving the tag unusable.

Inside the RF tags we can find an aluminum helical antenna, connected to a diode or an RC circuit. This type of systems do not require power to operate, the anti-theft arches are responsible for sending an electromagnética that is absorbed by these labels that activate their circuit generating a return signal.

In the detection system based on EAS RF an emitter and receiver device is required, the most used are the anti-theft arches.
One of them works as an emitter and another as a receiver. Its installation must be done at the entrance or exit of the business and not placed less than 80 cm from each other.
These arches needan own food and can be regulated to be more or less sensitive.

The detection operation consists in that the emitter arc is sending (A) a signal that activates the label, when passing an alarm tag between the two arcs the label receives the signal from the emitter arc, this signal emitted by the label is received by the receiver arc (B) that is in charge of making the alarm go off.

The EAS RF deactivator is a device designed to electronically disable soft, adhesive and disposable anti-theft labels.

Its design is usually flat type, to facilitate its placement and installation on tables, counters etc.

Its operation is simple, it is only necessary to pass the label over the deactivator (A) and it will be unusable.

To deactivate the tagta (B) the system applies a very high electric impulse (C), this impulse is able to disable (destroy) the diode incorporated in the circuit of the label.

Once the label passes through the arc it will not detect the diode and the alarm will not be activated.

Within the wide range of batteries on the market we can differentiate two large groups, disposable batteries and rechargeable batteries.
Disposable batteries are those that only allow a single use and when they are exhausted they can not be recharged. These batteries can store their energy for years.

Rechargeable batteries are those that can be recharged once exhausted. This type is losing charge when they are storedaccording to voltage. The most common we can find them of 1.2V and 3.7V

As a last point you have to take into account that lithium batteries, Lipo, Life etc. Due to its composition, specific loaders should be used.