What are Active, Passive Electronics Components and Methods to Measure Voltage, Current and Resistance

What are Active and Passive elements in a circuit and How to measure Voltage, Current and Resistance in any Electronics Circuit?

The electronic components

You have already learned what it is current, voltage, resistance and how this knowledge can be used during the experiments. Since this article concerns the basics of electronics, we will go now to classify the basic "building material" or electronic components.

Namely, the elements can be divided into two groups: active and passive.

The passive elements are capable of generating electric power or to change its parameters affected by other parameters of the circuit (voltage or current). Their only job is to its storage (coil, a capacitor) or simply "losing" (resistor).

Active Elements,  are those which generate electricity or are able to change their parameters, depending on the current applied to them and / or voltage. This group includes, first of all, the power source (battery), and transistors and integrated circuits

Contrary to appearances, this classification is not only artificial, theoretical creation, it has great practical importance. This allows the separation of the components involved in the processing of currents or voltages from those that accompany them.

Looking at this classification it can be stated that passive components, in particular resistors, which can only consume valuable energy, are unnecessary.

Measurements few words

Each electronics circuit should be able to properly measure the three basic values: voltage, current and resistance . At the beginning, the simplest operation, voltage measurement , which is measured always in parallel! For example, measure the voltage of 9 V battery.

Be sure to set your multi meter to measure DC voltage. Try to set the measuring ranges in such a way that they expect the next maximum value. Our systems will be safest when the meter set to the scope to measure 0-20 V for 9 v battery.

It should be noted that if the scope of the measurement of voltage (or current) is greater than the measuring range of multi-meter it may damage the multi-meter  (not applicable to resistance measurement).

Voltage measurement.

While the current measurement is performed in series . Remember that most multi-meters, during the current measurement requires a different wiring than the voltage measurement. Before the first test check the instructions!

Measuring the output current by applying an ammeter leads to a power source may end up damaging the machine or fire.

current measurement

In summary measurement of voltage and current, it is necessary to have in mind the following principle. Please note that the current measurement requires open-circuit in one place.

Methods for measuring voltage and current.

The measurement of the resistance , and - if the resistor (resistor) is in the system, disconnect at least one of his leg.

Measurement of resistance.

Touching fingers pin resistor with resistance measurements may introduce an error of unknown value. If necessary, better to keep it, at most, per foot.