What is a trigger

Who does not know what a trigger is? This is one of the very first devices encountered by a radio amateur after getting acquainted with the basic elements of electronics, such as resistors, capacitors, transistors.

So what is a trigger?

By definition, this is an element that has twostable states. The simplest example, not related to electronics, is the switch. He also has two stable states - on (on) and off (off). For a trigger, these states will sound accordingly - in a single state (on) or reset (off). In the single state, the voltage at the output of the flip-flop is slightly less than the supply voltage, in the reset state, the voltage is low. Hence its name comes, i.e. the element is in one position. In the English translation, the trigger is a latch.

The simplest is an electronic trigger ontransistors. To produce it, you need two transistors, several capacitors and resistors. The first use of the trigger will be to use it as a switch.

Often you have to perform a simple action -press the button and then release it. So, usually this action is remembered by the trigger. When the button is pressed, it is set to a single state, and then the device already understands that it needs to work in the mode set by the pressed button. To exit this mode, press another button, then the trigger will be reset, and a new operating mode will be set.

However, all of the above is not a complete answer to the question, what is a trigger. This is only one of the possibilities of its use.

There is a wide variety of triggering schemes, even there is a special class of integrated circuits that are also elements with stable states.

Various types of flip-flops are implemented, differing in circuitry and control principles.

It's enough just to mention such elements asD-, RS-, JK-trigger, synchronous, asynchronous, single-stage, two-stage, counting triggers. All these options are elements of digital devices. They are used when performing a variety of tasks, from memorizing the state of the button (pressed or not) to participating in signal processing.

Therefore, the question of what a trigger is, you can get quite different answers:

is a memory element of digital devices, a unit memory cell;

is a logical element involved in processing a digital signal;

is the basic element of digital circuitry.

However, even all that is already listed is notcovers the possibilities of using the trigger. So, it can be implemented on electromechanical relays or on power cells. You can use the trigger to control the power elements.

It is not only the idea of ​​electronicdevices on transistors, but also the idea of ​​using the principle of a latch, the principle of performing an action when a certain event occurs. This is especially often used in programming. And in many other cases, such a method is implemented. This is a very convenient principle when a subsequent event occurs after the specified conditions are met.

Therefore, it is hardly possible to obtain an unambiguous answer to the question of what a trigger is. Here it is necessary to clarify what is meant by this word.

If this is an electronic product or an element of digital circuitry, then the answer is one.

If the word "trigger" means the principleapplication, concerning the use of the concept of a latch, fixation of the onset of an event, then the areas where this principle can be implemented can be very different, from programming to other spheres of human activity.

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