Here we begin with DC power source. We all want to do something big when we start learning something, but before making big things we need to begin with the initial knowledge because before running we need to be able to walk.
Same like this we need basic circuitry information before to make many more great things. In this will we see how to use different electronic components in a circuit and what is the use of them.
DC POWER SOURCE
Here we can see two DC power sources, one is a battery of 5V which has two terminals positive and negative & in another diagram we see one terminal as power of +5V and other is ground, so that potential difference across them becomes 5V and works the same as battery.
So in these tutorials you will sometimes see battery symbol and sometimes power and ground.
All power & ground symbols in a circuit are supposed to same source (Suppose in a circuit I need two +5V, for this I have two choices to show either connect a wire or placed another power of same +5V).
See diagram below both circuits are same
MULTIMETER TESTING OF BATTERY
Rotate multimeter knob over DC voltage according to battery range, suppose I know my battery is of 9V so it lays fewer than 20, that’s why I rotate knob over DC 20 V. Now, make contact of red wire and black wire with battery positive and negative terminal respectively i.e. (positive to positive & negative to negative).
If you don’t know about how much voltage can be there you need to rotate the knob as it gives 1 in multimeter.
ACTIVE AND PASSIVE COMPONENTS
According to wikipedia
Active components rely on a source of energy (usually from the DC circuit, which we choose to ignore) and usually can inject power into a circuit, though this is not part of the definition.
Examples of active components include amplifying components such as transistors, triode vacuum tubes (valves), and tunnel diodes.
Passive components can’t introduce net energy into the circuit. They also can’t rely on a source of power, except for what is available from the (AC) circuit they are connected to.
As a consequence they can’t amplify (increase the power of a signal), although they may increase a voltage or current (such as is done by a transformer or resonant circuit).
Examples of passive components include two-terminal components such as resistors, capacitors, inductors, and transformers.
DIFFERENT TYPES OF SWITCHES