This page contains several dozen electrical circuit diagrams and useful links to resources related to the topic of equipment repair. Mainly computer. Remembering how much effort and time sometimes had to be spent searching for the necessary information, a reference book or a diagram, I have collected here almost everything that I used during repairs and that was available in electronic form. I hope this is of some use to someone.
Utilities and reference books.
The program is designed to determine the capacitance of a capacitor by color marking (12 types of capacitors).
startcopy.ru - in my opinion, this is one of the best sites on the RuNet dedicated to the repair of printers, copiers, and multifunctional devices. You can find techniques and recommendations for fixing almost any problem with any printer.
Power supplies.
Power supply circuits for ATX 250 SG6105, IW-P300A2, and 2 circuits of unknown origin.
NUITEK (COLORS iT) 330U power supply circuit.
Codegen 250w mod power supply circuit. 200XA1 mod. 250XA1.
Codegen 300w mod power supply circuit. 300X.
PSU diagram Delta Electronics Inc. model DPS-200-59 H REV:00.
PSU diagram Delta Electronics Inc. model DPS-260-2A.
DTK PTP-2038 200W power supply circuit.
Power supply diagram FSP Group Inc. model FSP145-60SP.
Green Tech power supply diagram. model MAV-300W-P4.
Power supply circuits HIPER HPU-4K580
Power supply diagram SIRTEC INTERNATIONAL CO. LTD. HPC-360-302 DF REV:C0
Power supply diagram SIRTEC INTERNATIONAL CO. LTD. HPC-420-302 DF REV:C0
Power supply circuits INWIN IW-P300A2-0 R1.2.
INWIN IW-P300A3-1 Powerman power supply diagrams.
JNC Computer Co. LTD LC-B250ATX
JNC Computer Co. LTD. SY-300ATX power supply diagram
Presumably manufactured by JNC Computer Co. LTD. Power supply SY-300ATX. The diagram is hand-drawn, comments and recommendations for improvement.
Power supply circuits Key Mouse Electronics Co Ltd model PM-230W
Power supply circuits Power Master model LP-8 ver 2.03 230W (AP-5-E v1.1).
Power supply circuits Power Master model FA-5-2 ver 3.2 250W.
Maxpower PX-300W power supply circuit
Utilities and reference books.
- Directory in .chm format. The author of this file is Pavel Andreevich Kucheryavenko. Most of the source documents were taken from the website pinouts.ru - brief descriptions and pinouts of more than 1000 connectors, cables, adapters. Descriptions of buses, slots, interfaces. Not only computer equipment, but also cell phones, GPS receivers, audio, photo and video equipment, game consoles and other equipment.The program is designed to determine the capacitance of a capacitor by color marking (12 types of capacitors).
Database on transistors in Access format.
Power supplies.
Contact table for the 24-pin ATX power supply connector (ATX12V) with wire ratings and color coding
| Comte | Designation | Color | Description | |
|---|---|---|---|---|
| 1 | 3.3V | Orange | +3.3 VDC | |
| 2 | 3.3V | Orange | +3.3 VDC | |
| 3 | COM | Black | Earth | |
| 4 | 5V | Red | +5 VDC | |
| 5 | COM | Black | Earth | |
| 6 | 5V | Red | +5 VDC | |
| 7 | COM | Black | Earth | |
| 8 | PWR_OK | Grey | Power Ok - All voltages are within normal limits. This signal is generated when the power supply is turned on and is used to reset the system board. | |
| 9 | 5VSB | Violet | +5 VDC Standby voltage | |
| 10 | 12V | Yellow | +12 VDC | |
| 11 | 12V | Yellow | +12 VDC | |
| 12 | 3.3V | Orange | +3.3 VDC | |
| 13 | 3.3V | Orange | +3.3 VDC | |
| 14 | -12V | Blue | -12 VDC | |
| 15 | COM | Black | Earth | |
| 16 | /PS_ON | Green | Power Supply On. To turn on the power supply, you need to short-circuit this contact to ground (with a black wire). | |
| 17 | COM | Black | Earth | |
| 18 | COM | Black | Earth | |
| 19 | COM | Black | Earth | |
| 20 | -5V | White | -5 VDC (this voltage is used very rarely, mainly to power old expansion cards.) | |
| 21 | +5V | Red | +5 VDC | |
| 22 | +5V | Red | +5 VDC | |
| 23 | +5V | Red | +5 VDC | |
| 24 | COM | Black | Earth |
Power supply diagram ATX-300P4-PFC (ATX-310T 2.03).
ATX-P6 power supply diagram.
API4PC01-000 400w power supply diagram manufactured by Acbel Politech Ink.
Power supply diagram Alim ATX 250Watt SMEV J.M. 2002.
Typical diagram of a 300W power supply with notes about functional purpose individual parts of the circuit.
Typical circuit of a 450W power supply with the implementation of active power factor correction (PFC) of modern computers.
API3PCD2-Y01 450w power supply diagram manufactured by ACBEL ELECTRONIC (DONGGUAN) CO. LTD.
Power supply circuits for ATX 250 SG6105, IW-P300A2, and 2 circuits of unknown origin.
NUITEK (COLORS iT) 330U (sg6105) power supply circuit.
NUITEK (COLORS iT) 330U power supply circuit on the SG6105 chip.
NUITEK (COLORS iT) 350U SCH power supply circuit.
NUITEK (COLORS iT) 350T power supply circuit.
NUITEK (COLORS iT) 400U power supply circuit.
NUITEK (COLORS iT) 500T power supply circuit.
PSU circuit NUITEK (COLORS iT) ATX12V-13 600T (COLORS-IT - 600T - PSU, 720W, SILENT, ATX)
PSU diagram CHIEFTEC TECHNOLOGY GPA500S 500W Model GPAxY-ZZ SERIES.
Codegen 250w mod power supply circuit. 200XA1 mod. 250XA1.
Codegen 300w mod power supply circuit. 300X.
PSU circuit CWT Model PUH400W.
PSU diagram Delta Electronics Inc. model DPS-200-59 H REV:00.
PSU diagram Delta Electronics Inc. model DPS-260-2A.
Power supply circuit DTK Computer model PTP-2007 (aka MACRON Power Co. model ATX 9912)
DTK PTP-2038 200W power supply circuit.
EC model 200X power supply circuit.
Power supply diagram FSP Group Inc. model FSP145-60SP.
PSU standby power supply diagram FSP Group Inc. model ATX-300GTF.
PSU standby power supply diagram FSP Group Inc. model FSP Epsilon FX 600 GLN.
Green Tech power supply diagram. model MAV-300W-P4.
Power supply circuits HIPER HPU-4K580. The archive contains a file in SPL format (for the sPlan program) and 3 files in GIF format - simplified circuit diagrams: Power Factor Corrector, PWM and power circuit, autogenerator. If you have nothing to view .spl files, use diagrams in the form of pictures in .gif format - they are the same.
Power supply circuits INWIN IW-P300A2-0 R1.2.
INWIN IW-P300A3-1 Powerman power supply diagrams.
The most common malfunction of Inwin power supplies, the diagrams of which are given above, is the failure of the standby voltage generation circuit +5VSB (standby voltage). As a rule, it is necessary to replace the electrolytic capacitor C34 10uF x 50V and the protective zener diode D14 (6-6.3 V). In the worst case, R54, R9, R37, microcircuit U3 (SG6105 or IW1688 (complete analogue of SG6105)) are added to the faulty elements. For the experiment, I tried installing C34 with a capacity of 22-47 uF - perhaps this will increase the reliability of the duty station.
Power supply diagram Powerman IP-P550DJ2-0 (IP-DJ Rev:1.51 board). The standby voltage generation circuit in the document is used in many other models of Power Man power supplies (for many power supplies with a power of 350W and 550W, the differences are only in the ratings of the elements).
JNC Computer Co. LTD LC-B250ATX
JNC Computer Co. LTD. SY-300ATX power supply diagram
Presumably manufactured by JNC Computer Co. LTD. Power supply SY-300ATX. The diagram is hand-drawn, comments and recommendations for improvement.
Power supply circuits Key Mouse Electroniks Co Ltd model PM-230W
Power supply circuits L&C Technology Co. model LC-A250ATX
LWT2005 power supply circuits on the KA7500B and LM339N chip
M-tech KOB AP4450XA power supply circuit.
PSU diagram MACRON Power Co. model ATX 9912 (aka DTK Computer model PTP-2007)
Maxpower PX-300W power supply circuit
PSU diagram Maxpower PC ATX SMPS PX-230W ver.2.03
Power supply diagrams PowerLink model LP-J2-18 300W.
Power supply circuits Power Master model LP-8 ver 2.03 230W (AP-5-E v1.1).
Power supply circuits Power Master model FA-5-2 ver 3.2 250W.
Microlab 350W power supply circuit
Microlab 400W power supply circuit
Powerlink LPJ2-18 300W power supply circuit
PSU circuit Power Efficiency Electronic Co LTD model PE-050187
Rolsen ATX-230 power supply circuit
SevenTeam ST-200HRK power supply diagram
PSU circuit SevenTeam ST-230WHF 230Watt
SevenTeam ATX2 V2 power supply circuit
An integral part of every computer is power supply unit (PSU). It is just as important as the rest of the computer. At the same time, purchasing a power supply is quite rare, since a good power supply can provide power to several generations of systems. Taking all this into account, the purchase of a power supply must be taken very seriously, since the fate of the computer is directly dependent on the performance of the power supply.
The main purpose of the power supply issupply voltage generation, which is necessary for the functioning of all PC blocks. The main component supply voltages are:
- +12V
- +3.3V
There are also additional voltages:
- −12V
To implement galvanic isolation It is enough to make a transformer with the necessary windings. But to power a computer you need a considerable power, especially for modern PCs. For computer power supply it would be necessary to manufacture a transformer that would not only be large in size, but also weigh a lot. However, with increasing frequency of the transformer supply current to create the same magnetic flux Fewer turns and a smaller cross-section of the magnetic core are required. In power supplies built on the basis of a converter, the frequency of the transformer supply voltage is 1000 or more times higher. This allows you to create compact and lightweight power supplies.
The simplest pulse power supply
Consider a block diagram of a simple switching power supply, which underlies all switching power supplies.
Block diagram of a switching power supply.
The first block implements conversion of AC network voltage to DC. Such converter consists of a diode bridge that rectifies alternating voltage and a capacitor that smoothes out ripples of the rectified voltage. This box also contains additional elements: filters mains voltage from ripples of the pulse generator and thermistors to smooth out the current surge at the moment of switching on. However, these elements may be omitted in order to save on cost.
Next block - pulse generator, which generates pulses at a certain frequency that power the primary winding of the transformer. The frequency of generating pulses of different power supplies is different and ranges from 30 to 200 kHz. The transformer performs the main functions of the power supply: galvanic isolation from the network and reducing the voltage to the required values.
The alternating voltage received from the transformer is converted by the next block into direct voltage. The block consists of voltage rectifying diodes and a ripple filter. In this block, the ripple filter is much more complex than in the first block and consists of a group of capacitors and a choke. In order to save money, manufacturers can install small capacitors, as well as chokes with low inductance.
First pulse block nutrition represented push-pull or single-cycle converter. Push-pull means that the generation process consists of two parts. In such a converter, two transistors open and close in turn. Accordingly, in a single-ended converter one transistor opens and closes. Circuits of push-pull and single-cycle converters are presented below.
.
Let's take a closer look at the elements of the circuit:
X2 - connector power supply circuit.
X1 is the connector from which the output voltage is removed.
R1 is a resistance that sets the initial small bias on the keys. It is necessary for a more stable start of the oscillation process in the converter.
R2 is a resistance that limits the base current on the transistors; this is necessary to protect the transistors from burning out.
TP1 - The transformer has three groups of windings. The first output winding generates the output voltage. The second winding serves as a load for the transistors. The third generates the control voltage for the transistors.
At the initial moment of turning on the first circuit, the transistor is slightly open, since a positive voltage is applied to the base through resistor R1. A current flows through the slightly open transistor, which also flows through winding II of the transformer. The current flowing through the winding creates a magnetic field. The magnetic field creates voltage in the remaining windings of the transformer. As a result, a positive voltage is created on winding III, which opens the transistor even more. The process continues until the transistor reaches saturation mode. The saturation mode is characterized by the fact that as the applied control current to the transistor increases, the output current remains unchanged.
Since the voltage in the windings is generated only if there is a change magnetic field, its increase or decrease, then the absence of an increase in the current at the output of the transistor will, therefore, lead to the disappearance of the EMF in windings II and III. A voltage loss in winding III will lead to a decrease in the degree of opening of the transistor. And the output current of the transistor will decrease, therefore, the magnetic field will decrease. Decreasing the magnetic field will create a voltage of opposite polarity. The negative voltage in winding III will begin to close the transistor even more. The process will continue until the magnetic field completely disappears. When the magnetic field disappears, the negative voltage in winding III will also disappear. The process will begin to repeat itself again.
A push-pull converter works on the same principle, but the difference is that there are two transistors, and they open and close in turn. That is, when one is open, the other is closed. The push-pull converter circuit has the great advantage of using the entire hysteresis loop of the magnetic conductor of the transformer. Using only one section of the hysteresis loop or magnetizing in only one direction leads to many undesirable effects that reduce the efficiency of the converter and degrade its performance. Therefore, a push-pull converter circuit with a phase-shifting transformer is generally used everywhere. In circuits where simplicity, small dimensions, and low power are needed, a single-cycle circuit is still used.
ATX form factor power supplies without power factor correction
The converters discussed above, although complete devices, are inconvenient to use in practice. The converter frequency, output voltage and many other parameters “float”, changing depending on changes in: supply voltage, converter output load and temperature. But if the keys are controlled by a controller that could carry out stabilization and various additional features, then you can use the circuit to power the devices. The power supply circuit using a PWM controller is quite simple, and, in general, is a pulse generator built on a PWM controller.
PWM – pulse width modulation. It allows you to adjust the amplitude of the signal passed through the LPF (low pass filter) by changing the duration or duty cycle of the pulse. The main advantages of PWM are the high efficiency of power amplifiers and great application possibilities.
This power supply circuit has low power and uses a field-effect transistor as a switch, which allows you to simplify the circuit and get rid of additional elements required to control transistor switches. IN high power power supplies PWM controller has controls (“Driver”) for the output switch. IGBT transistors are used as output switches in high-power power supplies.
The mains voltage in this circuit is converted into direct voltage and is supplied through a switch to the first winding of the transformer. The second winding serves to power the microcircuit and generate voltage feedback. The PWM controller generates pulses with a frequency that is set by an RC circuit connected to pin 4. The pulses are fed to the input of the switch, which amplifies them. The duration of the pulses varies depending on the voltage on leg 2.
Let's consider a real ATX power supply circuit. It has many more elements and additional devices are present in it. The power supply circuit is conventionally divided into main parts by red squares.
ATX power supply circuit with a power of 150–300 W
To power the controller chip, as well as generate the standby voltage +5, which is used by the computer when it is turned off, there is another converter in the circuit. In the diagram it is designated as block 2. As you can see, it is made according to the circuit of a single-cycle converter. The second block also contains additional elements. Basically, these are chains for absorbing voltage surges that are generated by the converter transformer. Microcircuit 7805 – voltage stabilizer generates a standby voltage of +5V from the rectified voltage of the converter.
Often, low-quality or defective components are installed in the standby voltage generation unit, which causes the frequency of the converter to decrease to the audio range. As a result, a squeaking sound is heard from the power supply.
Since the power supply is powered from an AC network voltage 220V, and the converter needs power constant voltage, the voltage needs to be converted. The first block rectifies and filters alternating mains voltage. This block also contains a filter against interference generated by the power supply itself.
The third block is the TL494 PWM controller. It carries out all the main functions of the power supply. Protects the power supply from short circuits, stabilizes output voltages and generates a PWM signal to control transistor switches that are loaded on the transformer.
The fourth block consists of two transformers and two groups of transistor switches. The first transformer generates the control voltage for the output transistors. Since the TL494 PWM controller generates a low power signal, the first group of transistors amplifies this signal and passes it to the first transformer. The second group of transistors, or output ones, are loaded onto the main transformer, which generates the main supply voltages. This more complex output switch control circuit was used due to the complexity of controlling bipolar transistors and protecting the PWM controller from high voltage.
The fifth block consists of Schottky diodes, which rectify the output voltage of the transformer, and a low-pass filter (LPF). The low-pass filter consists of electrolytic capacitors of significant capacity and chokes. At the output of the low-pass filter there are resistors that load it. These resistors are necessary to ensure that the power supply capacity does not remain charged after turning off. There are also resistors at the output of the mains voltage rectifier.
The remaining elements not circled in the block are chains and form “ service signals" These chains protect the power supply from short circuits or monitor the health of the output voltages.
Now let's see how to printed circuit board 200 W power supply elements are located. The picture shows:
Capacitors that filter output voltages.
Place of unsoldered output voltage filter capacitors.
Inductors that filter the output voltages. The larger coil not only plays the role of a filter, but also acts as a ferromagnetic stabilizer. This allows you to slightly reduce voltage imbalances when the load of different output voltages is uneven.
WT7520 PWM stabilizer chip.
A radiator on which Schottky diodes are installed for voltages of +3.3V and +5V, and for voltages of +12V there are ordinary diodes. It should be noted that often, especially in older power supplies, additional elements are placed on the same radiator. These are voltage stabilization elements +5V and +3.3V. In modern power supplies, only Schottky diodes for all main voltages or field-effect transistors, which are used as a rectifying element, are placed on this radiator.
The main transformer, which generates all voltages, as well as galvanic isolation from the network.
A transformer that generates control voltages for the output transistors of the converter.
Converter transformer generating standby voltage +5V.
The radiator on which the output transistors of the converter are located, as well as the transistor of the converter that generates the standby voltage.
Mains voltage filter capacitors. There don't have to be two of them. To form a bipolar voltage and form a midpoint, two capacitors of equal capacity are installed. They divide the rectified mains voltage in half, thereby forming two voltages of different polarity, connected at a common point. In schemes with unipolar power supply one capacitor.
Network filter elements against harmonics (interference) generated by the power supply.
Diode bridge diodes that rectify AC mains voltage.
Power supply 350 W arranged equivalently. What immediately catches your eye is the large board size, larger radiators and larger converter transformer.
Output voltage filter capacitors.
A radiator that cools the diodes that rectify the output voltage.
PWM controller AT2005 (analogous to WT7520), which performs voltage stabilization.
The main transformer of the converter.
A transformer that generates control voltage for output transistors.
Standby voltage converter transformer.
A radiator that cools the output transistors of the converters.
Mains voltage filter against power supply interference.
Diode bridge diodes.
Mains voltage filter capacitors.
The considered circuit has been used in power supplies for a long time and is now sometimes found.
ATX format power supplies with power factor correction
In the considered circuits, the network load is a capacitor connected to the network through a diode bridge. The capacitor is charged only if the voltage across it is less than the mains voltage. As a result, the current is pulsed in nature, which has many disadvantages.
We list these disadvantages:
- currents introduce higher harmonics (interference) into the network;
- large amplitude of current consumption;
- significant reactive component in the consumption current;
- mains voltage is not used during the entire period;
- The efficiency of such circuits is of little importance.
New power supplies have an improved modern circuit, it has one more additional block - power factor corrector (PFC). It improves the power factor. Or more in simple language eliminates some of the disadvantages of the mains voltage bridge rectifier.
S=P+jQ
Total Power Formula
Power factor (PF) characterizes how much of the total power there is an active component and how much is reactive. In principle, one can say, why take into account reactive power, it is imaginary and has no benefit.
Let's say we have a certain device, a power supply, with a power factor of 0.7 and a power of 300 W. It can be seen from the calculations that our power supply has a total power (the sum of reactive and active power) greater than that indicated on it. And this power should be provided by a 220V power supply. Although this power is not useful (even the electricity meter does not record it), it still exists.
That is, internal elements and network cables must be designed for a power of 430 W, not 300 W. Imagine a case where the power factor is 0.1... Because of this, GORSET prohibits the use of devices with a power factor of less than 0.6, and if such are detected, a fine is imposed on the owner.
Accordingly, the campaigns developed new power supply circuits that had PFC. Initially, a high-inductance inductor connected at the input was used as a PFC; such a power supply is called a power supply with PFC or passive PFC. Such a power supply has an increased KM. To achieve the desired CM, it is necessary to equip power supplies with a large choke, since the input resistance of the power supply is capacitive in nature due to the capacitors installed at the output of the rectifier. Installing a choke significantly increases the mass of the power supply, and increases the KM to 0.85, which is not so much.
The picture shows the company's power supply 400W FSP with passive power factor correction. It contains the following elements:
- Output voltage ripple filter capacitors.
Rectified mains voltage filter capacitors.
Throttle performing power factor correction.
Main converter transformer.
Transformer that controls the keys.
Auxiliary converter transformer (standby voltage).
Mains voltage filters against power supply ripples.
A radiator on which the output transistor switches are installed.
A radiator on which diodes are installed that rectify the alternating voltage of the main transformer.
Fan speed control board.
A board on which the FSP3528 PWM controller is installed (analogous to KA3511).
Group stabilization choke and output voltage ripple filter elements.
Due to the low efficiency of passive PFC, a new scheme PFC, which is built on the basis of a PWM stabilizer loaded onto a choke. This circuit brings many advantages to the power supply:
- extended operating voltage range;
- it became possible to significantly reduce the capacitance of the mains voltage filter capacitor;
- significantly increased CM;
- reducing the weight of the power supply;
- increasing the efficiency of the power supply.
There are also disadvantages to this scheme - these are decrease in power supply reliability and incorrect work with some uninterruptible power supplies I when switching operating modes battery / network. The incorrect operation of this circuit with a UPS is caused by the fact that the mains voltage filter capacitance in the circuit has significantly decreased. At the moment when the voltage disappears for a short time, the PFC current required to maintain the voltage at the PFC output increases greatly, as a result of which short circuit protection (short circuit) in the UPS is triggered.
If you look at the circuit, it is a pulse generator, which is loaded onto the inductor. The mains voltage is rectified by a diode bridge and supplied to the switch, which is loaded by inductor L1 and transformer T1. A transformer is introduced to provide feedback from the controller to the key. The voltage from the inductor is removed using diodes D1 and D2. Moreover, the voltage is removed alternately using diodes, either from the diode bridge or from the inductor, and charges the capacitors Cs1 and Cs2. Key Q1 opens and the required amount of energy is accumulated in throttle L1. The amount of accumulated energy is regulated by the duration of the open state of the key. The more energy accumulated, the more voltage will give up the throttle. After the key is turned off, the accumulated energy is released by the inductor L1 through the diode D1 to the capacitors.
This operation makes it possible to use the entire sinusoid of the alternating voltage of the network, in contrast to circuits without PFC, and also to stabilize the voltage supplying the converter.
In modern power supply circuits, they are often used dual channel PWM controllers. One microcircuit operates both the converter and the PFC. As a result, the number of elements in the power supply circuit is significantly reduced.
Let's consider the circuit of a simple 12V power supply using a two-channel PWM controller ML4819. One part of the power supply generates a constant stabilized voltage+380V. The other part is a converter that generates a constant stabilized voltage of +12V. The PFC consists, as in the case considered above, of switch Q1, inductor L1 of feedback transformer T1 loaded on it. Diodes D5, D6 charge capacitors C2, ° C3, ° C4. The converter consists of two switches Q2 and Q3, loaded onto transformer T3. The pulse voltage is rectified by diode assembly D13 and filtered by inductor L2 and capacitors C16, ° C18. Using cartridge U2, the output voltage control voltage is generated.
Let's consider the design of a power supply that has an active PFC:
- Current protection control board;
- A choke that performs the role of both a voltage filter +12V and +5V, and a group stabilization function;
- Voltage filter choke +3.3V;
- A radiator on which rectifier diodes of output voltages are located;
- Main converter transformer;
- Transformer that controls the keys of the main converter;
- Auxiliary converter transformer (forming standby voltage);
- Power factor correction controller board;
- Radiator, cooling diode bridge and main converter switches;
- Line voltage filters against interference;
- Power factor corrector choke;
- Mains voltage filter capacitor.
Design features and types of connectors
Let's consider types of connectors, which may be present on the power supply. On back wall power supply there is a connector for connecting network cable and a switch. Previously, next to the power cord connector, there was also a connector for connecting the monitor's network cable. Optionally, other elements may be present:
- indicators of mains voltage or power supply operating status
- fan operating mode control buttons
- button for switching input mains voltage 110 / 220V
- USB ports built into the USB hub power supply
- other.
Fans that extract air from the power supply are increasingly placed on the rear wall. Increasingly, the fan is placed at the top of the power supply due to the larger space for installing the fan, which allows you to install a large and quiet active cooling element. Some power supplies even have two fans installed, both on top and on the back.
Coming out from the front wall wire with motherboard power connector. In some modular power supplies, it, like other wires, is connected through a connector. The figure below shows.
You can notice that each voltage has its own wire color:
- Yellow color - +12 V
- Red color - +5 V
- Orange color - +3.3V
- Black color - common or ground
For other voltages, wire colors may vary from manufacturer to manufacturer.
Connectors are not shown in the figure. additional food video cards, since they are similar to the processor's additional power connector. There are also other types of connectors that are found in branded computers from DelL, Apple and others.
Electrical parameters and characteristics of power supplies
The power supply has many electrical parameters, most of which are not noted in the data sheet. On the side sticker of the power supply, only a few basic parameters are usually marked - operating voltages and power.
Power supply power
Power is often indicated on the label in large font. The power of the power supply characterizes how much it can deliver electrical energy devices connected to it (motherboard, video card, hard drive, etc.).
In theory, it is enough to sum up the consumption of the components used and select a power supply with a little more power for reserve. For power calculation These recommendations are quite suitable in the video card passport, if any, processor thermal package, etc.
But in reality, everything is much more complicated, because the power supply produces different voltages - 12V, 5V, −12V, 3.3V, etc. Each voltage line is designed for its own power. It was logical to think that this power is fixed, and their sum is equal to the power of the power supply. But the power supply contains one transformer to generate all these voltages used by the computer (except for the standby voltage +5V). True, it is rare, but you can still find a power supply with two separate transformers, but such power supplies are expensive and are most often used in servers. Conventional ATX power supplies have one transformer. Because of this, the power of each voltage line can float: it increases if other lines are lightly loaded, and decreases if other lines are heavily loaded. Therefore, the maximum power of each line is often written on power supplies, and as a result, if they are summed up, the power will be even greater than the actual power of the power supply. Thus, the manufacturer can confuse the consumer, for example, by declaring too high a rated power that the power supply is not capable of providing.
Please note that if your computer has Insufficient power supply, this will cause the devices to not operate correctly ( Freezes, reboots, clicking hard drive heads), to the point of impossibility turning on the computer. And if the PC has a motherboard installed that is not designed for the power of the components that are installed on it, then the motherboard often functions normally, but over time the power connectors burn out due to their constant heating and oxidation.
Standards and certificates
When purchasing a power supply, first of all you need to look at the availability of certificates and its compliance with modern international standards. The following standards can most often be found on power supplies:
- CCC - China Certificate of Safety, Electromagnetic and Environmental Compliance
RoHS, WEEE – does not contain harmful substances
UL, cUL – certificate of compliance with its technical specifications, as well as safety requirements for built-in electrical appliances
CE - a certificate that shows that the power supply meets the strictest requirements of the European Directives
ISO – international quality certificate
CB - international certificate of compliance with its technical characteristics
FCC - Electromagnetic interference (EMI) and radio frequency interference (RFI) compliance from the power supply
TUV - certificate of compliance with the requirements of the international standard EN ISO 9001:2000
There are also computer standards of the ATX form factor, which define the dimensions, design and many other parameters of the power supply, including permissible voltage deviations under load. Today there are several versions of the ATX standard:
- ATX 1.3 Standard
- ATX 2.0 Standard
- ATX 2.2 Standard
- ATX 2.3 Standard
The difference between the versions of ATX standards mainly concerns the introduction of new connectors and new requirements for the power supply lines of the power supply.
Recommendations for choosing a power supply
When does it occur need to buy a new power supply ATX, then first you need to determine the power that is needed to power the computer in which this power supply will be installed. To determine it, it is enough to sum up the power of the components used in the system, for example, using a special calculator. If this is not possible, then we can proceed from the rule that for an average computer with one gaming video card, a power supply with a power of 500–600 watts is sufficient.
Considering that most of the parameters of a power supply can only be found out by testing it, the next step we strongly recommend that you familiarize yourself with the tests and reviews of possible contenders - power supply models, which are available in your region and satisfy your needs at least in terms of power provided. If this is not possible, then you need to choose according to the power supply’s compliance with modern standards (the higher the number, the better), and it is desirable to have an APFC circuit in the power supply. When purchasing a power supply, it is also important to turn it on, if possible right at the place of purchase or immediately upon arriving home, and monitor how it works so that the power source does not make squeaks, hums or other extraneous noise.
In general, you need to choose a power supply that is powerful, well made, has good declared and actual electrical parameters, and also turns out to be easy to use and quiet during operation, even under high load. And under no circumstances should you save a few dollars when purchasing a power supply. Remember that the stability, reliability and durability of the entire computer mainly depends on the operation of this device.
The power supply is the most important part of any device, especially when it comes to a computer power supply. At one time I was involved in their repair, so I have accumulated some diagrams that can help you understand and, if necessary, repair them.
First, a little educational program on BP:
The power supply for a computer is built on the basis of a push-pull converter with a transformerless input. It is safe to say that 95 percent of all power supplies for computers are built precisely on this principle. The cycle for obtaining the output voltage contains several steps: the input voltage is rectified, smoothed and supplied to the power switches of the push-pull converter. The operation of these keys is carried out by a specialized microcircuit, usually called a PWM controller. This controller generates pulses supplied to power elements, usually power bipolar transistors, but recently there has been interest in powerful field effect transistors, therefore they can also be found in BP. Since the conversion circuit is push-pull, we have two transistors that must switch alternately with each other, if they turn on at the same time, then we can confidently assume that the power supply is ready for repair - in this case, the power elements burn out, sometimes the pulse transformer, it may also burn out something to load. The controller’s task is to ensure that such a situation does not occur in principle; it also monitors the output voltage, usually this is the +5V power supply circuit, i.e. this voltage is used for the feedback circuit and it is used to stabilize all other voltages. By the way, in Chinese power supplies there is no additional stabilization in the +12V, -12V, +3.3V circuits.
Voltage regulation is carried out using the pulse-width method: the pulse duty cycle usually changes, i.e. width log. 1 to the width of the entire pulse. The larger log.1, the higher the output voltage. All this can be found in special literature on power rectifier technology.
After the keys there is a pulse transformer, which transfers energy from the primary circuit to the secondary and at the same time carries out galvanic isolation from the 220V power circuit. Next, alternating voltage is removed from the secondary windings, which is rectified, smoothed and supplied to the output to power the motherboard and all computer components. This general description, which is not without its shortcomings. For questions about power electronics, you should refer to specialized textbooks and resources.
Below is the wiring layout for AT and ATX power supplies:
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To start the ATX power supply, you need to connect the Power Supply On wire to ground (black wire). Below are diagrams of power supplies for a computer:
ATX power supplies:
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File |
Description |
|---|---|---|
| 1 |
The diagram of an ATX power supply based on the TL494 chip is presented. | |
| 2 |
ATX POWER SUPPLY DTK PTP-2038 200W. | |
| 3 |