how to make power supply output 12 volt

1. Powersupply
By: eng Mahmoud amr

2. Power supply : is a hardware component that supplies power
to an electrical device. It receives power from an electrical
outlet and converts the current from AC (Alternating
Current) to DC (Direct Current)

3. What is AC ?
• (Alternating Current) Alternating current describes the flow of
charge that changes direction periodically. As a result, the
voltage level also reverses along with the current. AC is used to
deliver power to houses, office buildings, etc.
• AC can be produced using a device called an alternator. This
device is a special type of electrical generator designed to
produce alternating current
• Nikola Tesla ( 10 July 1856 – 7 January 1943) was a Serbian
American inventor, electrical engineer, mechanical engineer and
physicist best known for his contributions to the design of the
modern alternating current (AC) electricity supply system

4. What is DC ?
• ( Direct Current ) is the unidirectional flow of electric charge.
Direct current is produced by sources such as batteries, power
supplies, thermocouples, solar cells, or dynamos.
• Thomas Alva Edison (February 11, 1847 – October 18, 1931
was an American inventor and businessman. He developed many
devices that greatly influenced life around the world, including the
phonograph, the motion picture camera, and the long-lasting,
practical electric light

5. Ac vs DC

6. Where to use…?
mobile phone
charger
Power supply
For computer&lap
television
vehicles
space station
battery

7. Stages of power supply

8. Transformer
Transformer steps ac voltage up
or down

9. Rectifier
It is called a uniform or a fighter that transforms the current into a
constant current if the output is from the low voltage transformer
Voltage is an AC voltage that is converted to constant voltage if it is
12 volts or 24 volts and there is a type of current of current:

10. Half Wave Rectifier :
Let's understand it here when you supply the circuit with the known effort of "Polarity +" -
and pass the current when the "Forward" and "when"
Turns to Reverse The diode is closed and the current does not pass, so the output wave is as
shown. You are half the income and the part is
Positive.

11. Full Wave Rectifier :
The output as the input device is complete, the output is always the value of any
voltage in the output and Lysawy zero, we use 4 diodes
It is called the Bridage, and it is as clear in form when it is used in the first half of the
income, the positive part of it
Joins with the diode, from the top of the Briadge passes the current and converges in
the first part with the first and fourth column will be Forward with
The first diode and Reverse with the fourth diode, then passes in the second text,
Forward with the second Daewoo and Reverse with
The third diode and vice versa are true when the lower part of the income passes any
negative part of the router, and this user is in
The electronic circuit is a continuation of the income process.

13. The filter used is the capacitance and is used for several reasons, as we know that the condenser is
about two plates of metal, including insulator
Of the vacuum and the air and stores the energy (Energy) if the income of the AC exceeded the
value of more than 220 volt for whatever reason Vtad then the output of the power adapter and more
than the 12 volt or 24 volts and this causes serious problems
As for the electronic circuit and can cause damage to any element of the use of the capacitor absorbs
this energy
The electricity is inside and is supplied with this energy as the input voltage is lower and thus the
output of the power adapter, and to smooth the router
And remove any skewers and so-called Ripple Voltage and make the voltage of its value is
appropriate
The filter

14. Regulator :
A voltage regulator generates a fixed output voltage of a preset magnitude that remains
constant regardless of changes to its input voltage or load conditions. There are two types of
voltage regulators linear and switching.
• A linear regulator employs an active (BJT or MOSFET)
pass device (series or shunt) controlled by a high gain
differential amplifier. It compares the output voltage
with a precise reference voltage and adjusts the pass
device to maintain a constant output voltage
• A switching regulator converts the dc input voltage to a
switched voltage applied to a power MOSFET or BJT
switch. The filtered power switch output voltage is fed
back to a circuit that controls the power switch on and
off times so that the output voltage remains constant
regardless of input voltage or load current changes.

15. Circuit:
PCB design
Design

16. Things that need
• Piece of veroboard Four diodes or bridge
• LM7812 regulator
• Transformer that has an output of 20vAC with an output
current 1A
• 1000uF - 4700uF capacitor 1uF capacitor Two 100nF
capacitors
• Jumper wires
• And some tools