Simple power supply Circuit Schematic With Explanation

Simple power supply Circuit Schematic With Explanation

This circuit is very useful in beginners circuits, since most will work on 5v, which is the voltage of this easy little circuit.

How it works:

This circuit is just an implementation of the 7805 integrated voltage regulator. What this little component does is to lower a voltage and stabilize it by reducing noise and ripple, in order for circuits to have the constant voltage needed to work correctly

Simple power supply Circuit Schematic With Explanation

You can find the datasheet by following the link: 7805, take note of the typical applications notes, you can find some more uses for this versatile little regulator

2-25V 5A Power Supply LM338 circuit schematic with explanation

2-25V 5A Power Supply LM338

This power supply circuit uses a LM338 adjustable 3 terminal regulator to supply a current of up to 5A over a variable output voltage of 2V to 25V DC. It will come in handy to power up many electronic circuits when you are assembling or building any electronic devices. The schematic and parts list are designed for a power supply input of 240VAC. Change the ratings of the components if 110V AC power supply input is required.

The mains input is applied to the circuit through fuse F1. The fuse will blow if a current greater than 8A is applied to the system. Varistor V1 is used to clamp down any surge of voltage from the mains to protect the components from breakdown. Transformer T1 is used to step down the incoming voltage to 24V AC where it is rectified by the four diodes D1, D2, D3 and D4. Electrolytic capacitor E1 is used to smoothen the ripple of the rectified DC voltage.

Power supply parts list:

Diodes D5 and D6 are used as a protection devices to prevent capacitors E2 and E3 from discharging through low current points into the regulator. Capacitor C1 is used to bypass high frequency component from the circuit. Ensure that a large heat sink is mounted to LM338 to transfer the heat generated to the atmosphere.

More about 2-25V 5A Power Supply LM338

2N3055 and 741 power supply 20A 13.8V

This be high current power supply circuit , Which there is the size voltage 13.8V at 20A.By it uses base equipment that seeks to buy easy, be integrated number circuit LM741 perform maintain one’s position voltage be stable or Regulated at 13.8V. Which can fine can decorate a little again. Besides still have the power transistors 2N3055 X4 numbers bring to build parallel perform enlarge current tall arrive at 20Amp Other detail , see in the circuit.

Uninterruptable Power Supply (UPS)Comprehensive Note

Most of us take the mains ac supply for granted and use it almost casually without giving the slightest thought to its inherent shortcomings and the danger posed to sophisticated and sensitive electronic instruments/equipments. For ordinary household appliances such as incandencent lamps, tubes, fans, TV and fridge, the mains ac supply does not make much difference, but when used for computers, medical equipments and telecommunication systems, a clean, stable interruption free power supply is of the utmost importance. Of the myriad of devices, processes and systems which rely on ac power, computers are probably the most sensitive to power disturbances and failures. Interruptions in power supply may cause the contents of a memory to be lost or corrupted, the entire system to malfunction or fail, or even variety of components failures to occur, all of which not only result in inconvenience but also loss of money.

As more and more PCs, word processors and data terminals find their way into small business, UPS systems that meet the power requirements and price range needs of even the small business organizations and offices are being manufactured.

Un-interruptable Power Supply Systems.

There are three distinct types of uninter­rupted power supplies, namely, (£) on-line UPS (ii) off-line UPS, and (Hi) electronic gen­erators. In the on-line UPS, whether the mains power is on or off, the battery operated inverter is on all the time and supplies the ac output voltage. When the mains power supply goes off, the UPS will be on only until the battery gets discharged. When the main power resumes, the battery will get charged again. In off-line UPS and electronic genera­tors, ther inverter is off when the mains power is present and the output voltage derived directly from the mains is the same as the mains supply voltage. The inverter turns on only when the mains supply goes off.

The block diagrams of on-line UPS, off-line UPS and electronic generators are given in figs

The ever increasing importance of computers in industry and commerce will increase the need for quality, high stability and interruption free power supplies.

A clean ac power source is the fundamental to the operation of most sensitive elec­tronic equipment, and many new and sophisticated circuits are designed to overcome the effects of disturbances normally found in the mains ac supply.

In order to protect a sensitive system from power losses and blackouts, an alternative power source is required that can switch into operation immediately when disruption occurs. An interruptable power supply (UPS) is just such an alternative source. A UPS generally consists of a rectifier, battery charger, a battery bank and inverter circuit which converts the commercial ac input into dc suitable for input to the battery bank and the inverter. The rectifier should have its input protected and should be capable of supplying power to the inverter when the commercial supply is either slightly below the normal voltage or slightly above.

Online UPS:(Block Diagram)

In case of On-line UPS, the battery operated inverter works continuously whether the mains supply is present or not. Triac T₁ is on for all the times while Triac T₂ has been provided to bypass the UPS inverter, only when a fault develops in the UPS inverter. When the mains supply fails, the UPS supplies power only until the batteries get dis­charged. However, once the mains power resumes, the batteries will get charged again. The switching times of these supplies is considered to be zero. Usually sealed maintenance free batteries are used and the running time of the inverter is low (approximately 10 to 30 minutes).

Offline UPS:(Block Diagram)

In the case of Off-Line UPS, the inverter is off when the mains power is on and the output voltage is derived directly from the mains. The inverter turns on only when the mains supply fails. Its switching time is less than 5 ms. These UPS are generally used with PCs or computers or other appliances where a small duration (5 ms or less) interrup­tion in power supply can be tolerated. Usually, sealed batteries or lead-acid batteries are used. The running time of these supplies is also low (about 10 to 30 minutes).

Electronic Generator:

An electronic generator is the same as the off-line UPS system except for one difference that switching time from the mains supply to battery driven inverter supply will not be small (over 10 ms) for the electronic generator. Also, the electronic generators will run for longer time (1 to 4 hours) than off-line UPS systems because, usually large size lead-acid batteries are used with^/electronic generators. These are meant for household applications to run fans, coolers, fridge, lights, TV and VCR.

The demand is the highest for the electronic generators meant for house hold applica­tions, followed by the off-line UPS, and then the on-line UPS systems. The off-line or on­line UPS systems are mainly used in places where PCs or computers are used. The de­mand for on-line UPS systems is less than for off-line UPS systems because the price of the on-line UPS systems is higher.

S:circuitstoday.com

variable power supply(6A/0-28v)

The following diagram is the schematic diagram of variable power supply which will deliver 0 to 28V output voltage at 6/8 A electric current.

Component Part List:

R1 = 2K2 Ohm 2,5 Watt R2 = 240 Ohm R3,R4 = 0.1 Ohm 10 Watt R7 = 6K8 Ohm R8 = 10K Ohm R9 = 47 Ohm 0.5 Watt R10 = 8K2 Ohm C1, C7, C9 = 47nF C2 = 4700uF/50v – 6800uF/50v C3, C5 = 10uF/50v C4, C6 = 100nF C8 = 330uF/50v C10 = 1uF/16v C11 = 22nF

D1…D4 = four MR750 (MR7510) diodes (MR750 = 6 Ampere diode) or 2 x 4 1N5401 (1N5408) diodes. D5 = 1N4148, 1N4448, 1N4151 D6 = 1N4001 D10 = 1N5401 D11 = LED D7, D8, D9 = 1N4001 TR = 2 x 15 volt (30volt total) 6+- Ampere IC1 = LM317 T1, T2 = 2N3055 P1 = 5k P2 = 47 Ohm or 220 Ohm 1 Watt P3 = 10k trimmer F1 = 1 Amp F2 = 10 amp

Circuit Description:
This is an easy to make power supply that has reliable, clear and regulator 0 to 28 Volt 6/8 Amp output voltage. By making use of two 2N3055 transistor, you’ll get two times the amount of electric current.

Although the 7815 power regulator may kick in on short circuit, overload and thermal overheating, the fuses in the main section of the transformer and the fuse F2 at the output will safe your power supply. The rectified voltage of: 30 volt x SQR2 = 30 x 1.41 = 42.30 volt measured on C1. So all capacitors should be rated at 50 volts. Caution: 42 volt will be the voltage that could be on the output if 1 of the transistors ought to blow.

P1 lets you ‘regulate’ the output voltage to something in between 0 and 28 volts. The LM317 lowest voltage is 1.2 volt. To have a zero voltage on the output I’ve place 3 diodes D7,D8 and D9 around the output with the LM317 towards the base with the 2N3055 transistors. The LM317 optimum output voltage is 30 volts, but using the diodes D7,D8 & D9 the output voltage is approx 30v – (3x 0.6v) = 28.2volt.

Adjust your build-in voltmeter using P3 and, of course, a fine digital voltmeter is better solution.

P2 will let you to control the limit with the optimum available electric current in the output +Vcc. When utilizing a 100 Ohm / 1 watt varistor the current is limited to approx. 3 Amps @ 47 Ohm and +- 1 Amp @ 100

S:users.belgacom.net/hamradio/homebrew.htmOhms.

REGULATORS BASED DUAL VOLTAGE POWER SUPPLY

The following circuit Diagram of (DUAL VOLTAGE POWER SUPPLY ) can be used for Miscellaneous application.
It requires a few components to built. The most important components of this circuit are REGULATORS.

• (AN) 7812 : is the Positive Voltage Regulator, it regulates the voltage from (almost) 24vDC to 12vDC (accurate).
• (AN) 7912 AN7912 is the Negative Voltage Regulator. It regulates the voltage from (almost) -24vDC to -12vDC.

A transformer output must be between 12vAC to 24vAC @ 500mA. Input of transformer (Primary) should be about 110vAc-220vAC. It also include some capacitors to filter the current.

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2N3055 based High Current Power Supply Circuit

This is a unregulated dc power supply circuit which have ability to handle high current load.

Component parts:

R1_________ 680 Ohm 1/4 Watt Resistor
C1_________ 20,000 - 50,000uF 20-40 Volt Capacitor
C2, C3_____ 100uF/50 Volt Capacitor
C4_________ 0.1uF 50 Volt Capacitor
C5_________ 0.01uF 50 Volt Capacitor
D1_________ Zener Diode
Q1_________ 2N3055 Or Other
T1_________ Transformer
BR1________ Bridge Rectifier
S1_________ SPST 250 VAC 10 A Switch
MISC_______ Case, Line Cord, Heatsink For Q1, Binding Posts For Output

NOTES:

1. D1 should be rated at about one volt higher than then desired output of the supply. A half watt diode will do.
2. Q1 can be a transistor similar to the 2N3055.
3. T1 should be about 5 volts higher than the desired output of the supply, and rated for about one amp more of current. The voltage overhead is required by the regulator section. The extra current is to keep the transformer from over heating.

The choice of BR1 will depend on the voltage and current of your transformer. The rectifier should be rated for 50 volts more than the transformer, and 5 amps more than the transformer.

4. The value of R1 will be smaller when supplying high currents. Expiriment until you get what you need.
5. You are going to need to heatsink Q1 and BR1. Use a small PC case style fan unless you are going to run large heatsinks.

Bench Power Supply This is the schematic diagram of bench power supply . This bench powersupply will be great to support your activity if you are an

Bench Power Supply

This is the schematic diagram of bench power supply . This bench powersupply will be great to support your activity if you are an electronics hobbyst:

Take a note that based on the diagram, this circuit require 120V AC to 17V AC Center Tapped Transformer. If your country use 220V AC home electric source, you MUST change the Transformer 220-240V AC to 18V AC Center Tapped Transformer.

More information of this bench power supply, visit this page

General Static and Adjustable Power Supply circuit

Below general power supply circuit has 2 static output type, stabled output at 5VDC and adjustabled output or variable output.

Here the circuit diagram:

The circuit is based on the regulator IC 7805. It has only 3 connections (input, output and ground) and it provides a fixed output. The last two digits of the part number specify the output voltage, eg. 05, 06, 08, 10, 12, 15, 18, or 24. The 7800 series provides up to 1 amp load current and has on-chip circuitry to shut down the regulator (rather than blowing out) if any attempt is made to operate it outside its safe operating area. (If this happens to you, let the chip cool down and attach the heatsink.).

Visit this page more detail about general power supply.

Power Supply failure alarm Power Supply failure alarm circuit diagram This is an power supply failure alarm which will give you an alert when the pow

Power Supply failure alarm

This is an power supply failure alarm which will give you an alert when the power supply getting off or fail to supply. It employs an electrolytic capacitor to store adequate charge, to feed power to the alarm circuit which sounds an alarm for a reasonable duration when the supply fails.

To calibrate the circuit, first connect the power supply (5 to 15V) then vary the potentiometer VR1 until the buzzer goes from on to off.
Whenever the supply fails, resistor R2 pulls the base of transistor low and saturates it, turning the buzzer ON.

Take a note that this circuit will be work only on power supply with output voltage 5 - 15 Volt DC.

Source: http://www.electronic-circuits-diagrams.com/alarmsimages/alarmsckt2.shtml

Mastech Assembled Power Supply 0-30V / 0-5A

Do you need assembled power supply..? If your answer is yes, then this assembled digital power supply should be great to buy.

Product specification:

• Two level of control for both current and voltage outputs: coarse and fine for ease of use
• Adjustable outputs: 0-30V and 0-5A
• Input voltage: 110V AC and 220V AC switchable
• Ripple noise: CV <= 0.5 mV RMS, CC <= 3 mA RMS

You can BUY THIS POWER SUPPLY at Amazon.com

power supply low ripple regulated circuit diagram

This circuit may be used where a high current is required with a low ripple voltage (such as in a high powered class AB amplifier when high quality reproduction is necessary ).

PARTS LIST
R1	2.2KΩ 1W
R2	56Ω 1W
R3	1oKΩ 1W
C1	1000µF 63V
C2	100µF 50V
C3	470µF 50V
D1, D2, D3, D4	6A Bridge Rectifier
D5	500mA Zener Diode (see description)
Q1	2N3055
Q2	2N3054

Q1, Q2, and R2 may be regarded as a power darlington transistor. D5 and R1 provide a reference voltage at the base of Q1. D5 should be chosen thus: D5=V_out-1.2

C2 can be chosen for the degree of smoothness as its value is effectively multiplied by the combined gains of Q1/Q2, if 100µF is chosen for C2, assuming minimum hef for Q1 and Q2,

C=100×15(Q1)×25(Q2)

=37000µF.

S:electronicecircuits.com

Power supply (LM317)

The output is adjustable between 1.25 and 13.5 Volts with a maximum current limit of 1.5 Amps. The LM317K regulator is internally protected from current and thermal overloads. A heat sink will be required for most applications however.

Parts List

R1	220 Ω
R2	2 KΩ Variable Resistor
C1	3300 µf 50v
C2	10 µf 25v
C3	1 µf 25v
C4	0.1 µf
D1	100V 5A bridge rectifier
D2	IN 4007
D3	IN 4007
IC1	LM 317
T1	18 VAC 2AMP
F	250mA

The values of R1 and R2 are not critical but R1 should not be larger than 270 ohms. For a fixed voltage output R2 should be selected to give the desired maximum output voltage for a given R1 value. See the calculation on the drawing.

The diodes D2 and D3 in the circuit prevent damage to the regulator during certain adverse conditions such as the output voltage being higher than the input voltage to the regulator or the capacitor across R2 from discharging through the adjustment terminal of the regulator. These conditions will be rare but ten cents worth of protection can save the cost of a new regulator.

An Ammeter could be added to the circuit by placing it between the filter capacitor and the input terminal of the regulator.

design for amateurs 40A stabilized power supply circuit

This power supply is designed for amateurs, and has been in operation for over 10 years. Its design is very simple and practically immune to RF. It brings together the individual pieces, is the most expensive part of 600VA toroidal transformer, which can be replaced by another with different characteristics, in the case of a voltage between 17 ~ 20V power and right for our needs.

Reference voltage of 7.5 V Zenner diode (6V8 ~ 8V2), shall apply to Q2, which compares the input resistive voltage divider consisting of R5, R6 and VR2, steering Darlington amplifier Q3, which is responsible for driving the output stage, which consists of a driver in Q4 and 4 2N3771 NPN power transistor, which can be mounted directly on the heat sink without insulation, since it is a collector grounded.

The source has a current limit (Q1), adjusted by VR1 and overload LED (DL2) and full protection against short circuits, with zero consumption in case of short circuit can be maintained indefinitely in this state without danger.

(Please note that due to the strong power of the power supply with a casual a short length of cable, high or small section that is strong enough to not exceed the maximum current of 40A. Can not be considered a short circuit and cause the supply of a power supply large amounts of energy).

active rectifier (D1, D2) is recommended for a type of cathode metal screw is on the ground, install a heat sink large enough block. As power transistors using a hedgehog as high as possible, without being isolated as above, can be part of the window of an aluminum frame. We also recommend using mechanical ventilation with the thermostat.

QRO 600 volts power supply

Amateur Radio Transmitters using valves such as 807 or1625 works well with a plate voltage between 600V to 700 Volts.The circuit described here is a full wave voltage doubler. The output voltage is twice the input voltage. For 230V AC input the output will be nearly 600 Volts.

Resister R1 is used to limit the initial high voltage and high currents. Capacitor C1, C2, C3 together with coils L1 and L2 form input line filter. The capacitors C4 and C5 protects diodes from high voltage transients on the AC line as well as reduces inter carrier hum modulation of the R.F picked up by the mains. Capacitors C6 and C7 provides enough filtering for the output DC Voltage.

C1, C2, C3 - 0.1 mf 630V
C4,c5 0.01 mf 630V
C6, C7 100 mf 450V
R1 - 10E 5W Wire Wound
R2, R3     - 220KE 2Watts
D1, D2     - BY127
D3, D4     - BY127
L1, L2     - 12 Turns 18 SWG           
Wound over 4 Cm ong Ferrite Rode.

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Basic power suuply

Electronic devices should be powered by direct current supply DC (direct current) which is stable in order to work properly. The battery or batteries is a source of DC power supply is best. But for applications that require greater power supply, the source of the battery is not enough. Sources of power supply is a source of alternating AC (alternating current) from power plants. This requires a power supply device that can change the AC into DC current.

Now it should not need another effort to make good pwer supplay you do not need to look for op-amps, transistors and other components, because these circuits are packaged into a single fixed voltage regulator IC. Are now widely recognized as a component of 78XX series fixed positive voltage regulator and the 79XX series is a voltage regulator to remain negative. Even these components are usually already equipped with current limiting (current limiter) and also limiting the temperature (thermal shutdown). This component is only three pins, and by adding some components alone can be a series of power supply regulation was good.

Skema rangkaian power supplay

It's just to note that the IC regulator circuit that can work, the input voltage must be greater than the output voltage regulator. Usually the difference voltage Vin to the recommended VM is in the component datasheet. Usage heatshink (Aluminum cooling) is recommended if these components are used to supply large currents. In the datasheet, these components can pass the maximum current reached 1 A.

Tutorial Power Supply Units

Most electronic circuits need a DC supply such as a battery to power them.

Since the mains supply is AC it has to be converted to DC to be useful in electronics.
This is what a power supply does.

First the AC mains supply passes through an isolating switch and safety fuse before it enters the power supply unit.

In most cases the high voltage mains supply is too high for the electronic circuitry.
It is therefore stepped down to a lower value by means of a Transformer.
The mains voltage can be stepped up where high DC voltages are required.

From the transformer the AC voltage is fed to a rectifier circuit consisting of one or more diodes.
The rectifier converts AC voltage to DC voltage.

This DC is not steady as from a battery. It is pulsating.
The pulsations are smoothed out by passing them through a smoothing circuit called a filter.
In its simplest form the filter is a capacitor and resistor.

Any remaining small variations can, if necessary, be removed by a regulator circuit which gives out a very steady voltage.
This regulator also removes any variations in the DC voltage output caused by the AC mains voltage changing in value.
Regulators are available in the form of Integrated Circuits with only three connections.

6V Backup Power supply With Rechargeable Battery

The following circuit is a 6V backup power supply using a voltage regulator IC 7805. This circuit is suitable for use in areas that often cut off the electricity because it is equipped with a backup battery system. A rechargeable battery 6V is used as energy reserves and is automatically recharged when not in use.

In this power supply circuit, there are two essential elements of the DC power supply with AC transformer and DC Power supply that comes from a rechargeable battery (e.g. . DC power supply with a transformer is as a regular power supply system.

Power supply circuit equipped with a spare battery is very attractive and simple to construct. Description of component values can be seen in the power supply schematic below.

Backup Power Supply

You can change the power supply circuit with a larger capacity, replace the AC transformer and adjust the diode, and the final power transistor. Replacement Battery by selecting a larger capacity. Congratulations to experiment.

Dual Power Supply 78xx-79xx series This is a simple dual power supply using voltage regulator IC 78xx and 79xx series. It's the best and simplest choi

This is a simple dual power supply using voltage regulator IC 78xx and 79xx series. It's the best and simplest choice for most non-critical applications. The 3 terminals are input, ground and output. The 78xx & 79xx series can provide up to 1A load current and it have onchip circuitry to prevent damage in the event of over heating or excessive current.

Dual Power Supply Schematic

This dual power supply project provides a dual power supply. With the appropriate choice of transformer and 3-terminal voltage regulator pairs you can easily build a small power supply delivering up to one amp at +/- 5V, +/- 9V, +/- 12V, +/- 15V or +/-18V. You have to provide the centre tapped transformer and the 3-terminal pair of regulators you want: 7805 & 7905, 7809 & 7909, 7812 & 7912, 7815 & 7915or 7818 & 7918.

Note that the + and - regulators do not have to be matched: you can for example, use a +5v and -9V pair. However, the positive regulator must be a 78xx regulator, and the negative a 79xx one. We have built in plenty of safety into this project so it should give many years of continuous service.

These protect mainly against any back emf which may come back into the power supply when it supplies power to inductive loads. They also provide additional short circuit protection in the case that the positive output is connected by accident to the negative output. If this happened the usual current limiting shutdown in each regulator may not work as intended. The diodes will short circuit in this case and protect the 2 regulators.

Dual Power Supply Parts

5A Adjustable Voltage Power Supply

using LM338

Here’s a variable voltage power supply circuit using a LM338 adjustable 3 terminal regulator to supply a current of up to 5A over a variable output voltage of 2V to 25V DC. It will come in handy to power up many electronic circuits when you are assembling or building any electronic devices. The schematic and parts list are designed for a power supply input of 240VAC. Change the ratings of the components if 110V AC power supply input is required.

The mains input is applied to the circuit through fuse F1. The fuse will blow if a current greater than 8A is applied to the system. Varistor V1 is used to clamp down any surge of voltage from the mains to protect the components from breakdown. Transformer T1 is used to step down the incoming voltage to 24V AC where it is rectified by the four diodes D1, D2, D3 and D4. Electrolytic capacitor E1 is used to smoothen the ripple of the rectified DC voltage.

Diodes D5 and D6 are used as a protection devices to prevent capacitors E2 and E3 from discharging through low current points into the regulator. Capacitor C1 is used to bypass high frequency component from the circuit. Ensure that a large heat sink is mounted to LM338 to transfer the heat generated to the atmosphere.

Source: 2- 25V 5A Power Supply LM338