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As the most basic component of electronic circuits, resistors are used in various electronic circuits.
So why can resistors be used everywhere in electronic circuits? What exactly does it do? This article will give a detailed lecture.
According to the official encyclopedia of resistance, the resistance of a conductor to the current is called the resistance of the conductor.
This is also an essential characteristic of resistors and can hinder the current current. Because of this feature, resistors have evolved into a variety of use cases.
(1) Diversion
When it is necessary to connect several electrical appliances with different rated currents at the same time in the trunk circuit of the circuit, in order to prevent the electrical appliances with the smallest rated current from being burned, a resistor can be connected in parallel at both ends of the electrical appliances with small rated current, and the current flowing to the electrical appliances is less and plays the role of shunting.
(2) Current limitation
Increase the overall resistance value on the circuit, so that the current does not exceed the rated current of the electrical appliance or the specified value required for actual work, so as to ensure the normal operation of the electrical appliance.
(3) Partial pressure
Similar to shunts, general electrical appliances or ICs will have rated current and rated current, and the circuit design needs to ensure that the voltage is not exceeded when supplying voltage, so the series resistor allows it to share a part of the voltage to ensure that the voltage of the electrical device does not exceed the rated voltage.
(4) Convert electrical energy into internal energy
When an electric current passes through a resistor, it converts all or part of the electrical energy into internal energy, which has the effect of heating.
Such as common electric stoves, rice cookers, heaters, etc., the core is to convert electrical energy into internal energy.
(5) Pull-up, pull-down
This is mainly used in single-chip microcomputer circuits or complex circuits. The so-called pull-up is to pull the interface up to the resistor through the resistor, and make the level of the interface high in the initial state; The same goes for the pull-down, which pulls the interface down to GND through the resistor, and the level of the interface is low in the initial state. This allows the circuit to remain stable and not malfunction, causing unexpected or unwanted results.
Take CPU and key detection as an example:
(6) Filtering
It is usually combined with capacitors to form an RC filter to reduce and filter out noise and restore the real useful signal.
(7) Jumper function
This function is generally used in debugging, when designing the circuit, in order to facilitate later debugging, the pin and the chip are connected through a resistor, and the resistor is removed when not in use. At the same time, in the fault analysis, a certain circuit can be broken to facilitate FA analysis.
Of course, there is also a special resistance function, that is, 0 ohm resistance, which will be analyzed in a separate article later. You can pay attention to it so that you can receive updates as soon as possible.