The problem of choosing a case equipped with a modern high-quality power supply unit, which, in turn, has decent electrical and ergonomic parameters, is quite relevant. Often, cases are equipped with power supplies based on the principle of minimum sufficiency - "works and well". However, given the fact that completing the case with a power supply unit is not at all free for the buyer and the user, and the requirements for testing such power supplies should be corresponding.
Chassis testing will consist of two parts: testing the chassis itself and testing the complete power supply, and the latter will be tested according to a standard methodology, the same as for power supplies sold separately. This decision is also due to the fact that often the power supply unit that comes with any case can be seen on sale separately under its own name.
Today we are going to take a look at the ISO-450PP power supply included with the case. This PSU is manufactured by ISO Electronics (Mingbo) Co. LTD, part of the CWT Group, which is headquartered in Taiwan and has two power supply and converter factories in China.
Let's go directly to the external examination.
General description of the power supply
The power supply is housed in a steel casing with a thickness of about 0.6 mm, the edges are well processed, but not perfect. There are some pretty sharp edges that you can scratch or cut on. Burrs, edge chips and other unacceptable defects are absent. The PSU case has a standard gray color, no visible surface defects were found either.
On the external panel of the power supply unit are located:
- mains switch
- standard power cord connector
- marking of the permissible supply voltage (AC 230V)
- stamped air vent 75 x 75mm.
I would like to additionally note the well-known drawback of stamped hole grids compared to ventilation holes covered with mesh or wire - this is more high level noise arising from the passage of air through them, and also, often, a reduction in the usable area of the ventilation hole itself.
The back panel contains:
- a hole for the output of power wires with a plastic gasket that protects the wires from abrasion on the power supply case
- 23 ventilation holes 28 x 3 mm.
Additional ventilation holes for cooling the passive PFC module are located on the top, relative to the main printed circuit board, and one of the side walls of the PSU case.
- 24 pin ATX connector - monolithic. The length of the wires to the connector is 33 cm, after 24 cm from the body, a plastic tie is installed on them.
- 4-pin ATX12V connector, the length of the wires to the connector is 35 cm, the plastic tie is installed at a distance of 24 cm from the PSU case
- 1 SATA power connector, the length of the wires to the connector is 34 cm, the cable tie is installed at a distance of 24 cm from the power supply case.
- 2 connectors of the Molex type - the length of the wires up to the 1st connector is 34 cm, up to the 2nd - 14 cm, the tie is installed at a distance of 24 cm from the block body
- 2 Molex connectors plus a power connector for FDD - the length of the wires up to the 1st connector is 34 cm, up to the 2nd - 14 cm plus another 14 cm to the FDD connector, the tie is installed at a distance of 24 cm from the power supply case
- In total, the following are provided for powering devices inside the system unit:
- 4 Molex connectors
- 1 power connector for SATA devices
- 1 x FDD power connector
A common plastic tie is installed on all wires directly near the PSU housing.
The wires for connecting external devices and ATX connectors are used with a cross section of 18 AWG, which is quite enough for this power.
This model of the power supply uses a fan based on a sliding bearing manufactured by Xinruilian model with a maximum current consumption of 0.11A and a nominal rotation speed of 2500 rpm.
The fan wire is connected via a two-pin connector to the main PCB. No fan speed control circuits were seen.
One of the parts of the surge protector is soldered on an additional board installed on the radiator of the key transistors with the elements down and fixed with two self-tapping screws, the second part is on the main printed circuit board.
The high-voltage part of the PSU uses two 680μF capacitors manufactured by Teapo, designed for a maximum temperature of 85 degrees
The radiators of the key transistors and diode assemblies are the same, their base is 2 mm thick, the radiators are 7 cm long, 5 cm high, the cross-sectional size is 1 cm.In general, they do not shake with their dimensions, God forbid, that they are enough for normal cooling power supply elements during operation. The direction of the fins coincides with the rotation axis of the fan, which should have a positive effect on the heat dissipation. The radiators are standard F-shaped with double-sided fins. The block provides for the installation of a passive PFC module, it is located on the top cover. A microcircuit of the type is used as the main controller.
The output circuits are equipped with Teapo capacitors designed for a maximum temperature of 85 degrees with a capacity of 2200 mkF and 1000 mkF.
No places for unsoldered elements were found on the board.
The installation is quite neat, however, the wires connecting some of the power supply elements create an untidy look, despite the use of nylon ties.
Power supply testing
So, let's move on to testing.
The ripple test was performed at 75% of the declared maximum output power in accordance with the manufacturer's recommended load current distribution. Ripple was also measured at maximum load on the 12V channel.
| 3.3V | 5 in | 12 in | Power |
| 12 A | 20 A | 10 A | 260 watts |
| 6 A | 6 A | 16 A | 244 watts |
In general, ripple values are low and within acceptable limits. So, the maximum ripple value for the 5V channel was 9mV in the first case and 4mV in the second (the allowable limit is 50mV), and for the 12V channel - 6mV in the first case and 8mV in the second (the allowable limit is 120mV).
The voltage stability test was carried out on a number of output load currents, calculated according to the principle of their combination within the parameters declared by the manufacturer, but in the original proportions of 33, 66 and 100% for each channel of the calculated limit value, taking into account the maximum power consumption on the 12V line. Additionally, measurements were carried out in two arbitrary load combinations. As usual, voltages were measured with True RMS multimeters.
There are no complaints only about the 5V channel, voltage deviations in most cases are within three percent. The voltage deviations on the 12V channel can be considered, on the whole, satisfactory, although a couple of times they exceeded the permissible five percent threshold. The voltage value of 3.3V, as a rule, left the range of permissible values when the load of this line was more than 6A. In general, the power supply can be considered suitable for use in systems with low power consumption.
At the end of this stage of testing, the temperatures of the radiators were around 50 degrees, and the temperature of the power case was 32 degrees.
To assess the temperature regime of the power supply, additional measurements were carried out with fixing the temperatures of its structural elements. Testing was carried out with the top cover of the PSU closed.
Noteworthy heat radiators of power elements at a load very far from the maximum for this unit, and the 80mm fan rotated all the time at 2500 rpm and provided a very powerful air flow and, unfortunately, no less noticeable noise. Based on the test results, we can conclude that the design of the radiators is not well thought out, in other words, these radiators are not suitable for such operating modes.
For the next stage of testing, a computer with the following configuration was used:
- AMD Athlon 64 3000+ processor
- Cooler
- Matplata
- RAM Patriot LL 512 MB
- Gigabyte GV-N66256DP Graphics Card
- Hard drives: 2 HDD Samsung SP 0812C in RAID 0, HDD WD 1600JD
- Housing
There were no problems when installing into the case.
For testing we used: the utility in Demo mode (90 minutes) and the FarCry game (60 minutes). During testing, there were no freezes, reboots, errors, in a word, the system worked stably. The BP temperature was around 40 degrees. In general, the power supply worked for two days without any particular complaints. The only remark concerns increased level noise caused by the fact that the fan rotates at maximum speed all the time.
Deviations of voltages from the nominal within the normal range.
conclusions
This power supply should not be used with systems that consume more than 250W peak. The disadvantages of the design are small radiators, as well as the absence of fan control circuits, as a result of which a high noise level is observed.
The best scheme of a standard ATX PSU
ATX POWER SUPPLY DTK PTP-2038 200W
TL494
Features of the:
- Complete set of PWM control functions
- Output Sinking or Sinking current of each output 200mA
- Possibility to work in two-stroke or single-stroke mode
- Built-in double pulse suppression
- Wide adjustment range
- Output reference voltage 5V + -05%
- Simple organized sync
general description:
The TL493 / 4/5 microcircuits, specially designed for the construction of IVP, provide the developer with extended possibilities in the design of IVP control schemes. TL493 / 4/5 instruments include an error amplifier, built-in variable oscillator, dead time comparator, control trigger, 5V precision reference and output stage control circuit. The error amplifier outputs a common-mode voltage in the range of –0.3 ... (Vcc-2) V. The dead time control comparator has a constant offset that limits the minimum dead time to about 5%.
Synchronization of the built-in generator is allowed by connecting the R terminal to the reference voltage output and supplying the input sawtooth voltage to the C terminal, which is used when several IVP circuits work synchronously.
Independent transistor output formers provide the ability to operate the output stage according to a common emitter circuit or an emitter follower circuit. The output stage of the TL493 / 4/5 microcircuits operates in single-ended or push-pull mode with the ability to select the mode using a special input. A built-in circuit monitors each output and disables push-pull double pulse output.
Devices with the L suffix guarantee normal operation in the temperature range -5 ... 85C, with the C suffix guarantee normal operation in the 0 ... 70C temperature range.
Structural scheme:
Case pinout:
Limit values of parameters:
Supply voltage ………………………………………………………… .41V
Amplifier input voltage ……………………………………… ... (Vcc + 0.3) V
Collector output voltage ………………………………………… ...… 41V
Collector output current ……………………………………………….… 250mA
Total power dissipation in continuous mode ……………………… .1W
Ambient operating temperature range:
With the suffix L ……………………………………………………………… -25..85С
With the suffix C ……………………………………………………………… ..0..70С
Storage temperature range ……………………………………… ..- 65… + 150С
Repair of a switching power supply. Any person with basic electronic skills can independently repair a power supply or voltage converter. Proceed to identify the problem and rectify it. (10+)
We repair the switching power supply ourselves, with our own hands. Malfunctions
Attention! Some elements of the power supply are under mains voltage during operation. Make sure you are qualified to safely repair the switching power supply.
Diagnostics and repair of a switching power supply in most cases can be performed with basic skills in electronics.
Power supply device, step-down converter of mains voltage
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& nbsp & nbsp This page contains several dozen electrical schematic diagrams, and useful links to resources related to the topic of equipment repair. Mostly computer. Keeping in mind how much time and effort it sometimes took to find the necessary information, a reference book or a schematic diagram, I collected here almost everything that I used during the repair and that was available in electronic form. Hopefully someone will find something useful.
Utilities and reference books.
Capacitor 1.0 - The program is designed to determine the capacity of a capacitor by color marking (12 types of capacitors).
startcopy.ru - in my opinion, this is one of the best sites on the Russian Internet, dedicated to the repair of printers, copiers, multifunctional devices. You can find techniques and recommendations to fix almost any problem with any printer.
Power supplies.
ATXPower.rar - Diagrams of power supplies ATX 250 SG6105, IW-P300A2, and 2 diagrams of unknown origin.
colors_it_330u_sg6105.gif - NUITEK Power Supply Scheme (COLORS iT) 330U.
codegen_250.djvu - Power supply circuit diagram Codegen 250w mod. 200XA1 mod. 250XA1.
codegen_300x.gif - Power supply circuit diagram Codegen 300w mod. 300X.
deltadps200.gif - Power supply circuit diagram Delta Electronics Inc. model DPS-200-59 H REV: 00.
deltadps260.ARJ - Power supply circuit diagram Delta Electronics Inc. model DPS-260-2A.
DTK_PTP_2038.gif - DTK PTP-2038 200W power supply circuit.
FSP145-60SP.GIF - Power supply diagram of FSP Group Inc. model FSP145-60SP.
green_tech_300.gif - Green Tech power supply circuit. model MAV-300W-P4.
HIPER_HPU-4K580.rar - Power supply circuits HIPER HPU-4K580
hpc-360-302.pdf - Power supply circuit diagram SIRTEC INTERNATIONAL CO. LTD. HPC-360-302 DF REV: C0
hpc-420-302.pdf - Power supply circuit diagram SIRTEC INTERNATIONAL CO. LTD. HPC-420-302 DF REV: C0
iwp300a2.gif - Power supply circuits INWIN IW-P300A2-0 R1.2.
IW-ISP300AX.gif - INWIN IW-P300A3-1 Powerman power supply circuits.
JNC_LC-B250ATX.gif - JNC Computer Co. LTD LC-B250ATX
JNC_SY-300ATX.pdf - JNC Computer Co. LTD. SY-300ATX Power Supply Diagram
JNC_SY-300ATX.rar - Presumably the manufacturer of JNC Computer Co. LTD. SY-300ATX power supply. The diagram is hand-drawn, comments and recommendations for improvement.
KME_pm-230.GIF - Power supply circuits Key Mouse Electronics Co Ltd model PM-230W
Power_Master_LP-8_AP5E.gif - Power Master power supply circuits model LP-8 ver 2.03 230W (AP-5-E v1.1).
Power_Master_FA_5_2_v3-2.gif - Power Master power supply circuits model FA-5-2 ver 3.2 250W.
MaxpowerPX-300W.GIF - Schematic diagram of power supply unit Maxpower PX-300W
microlab350w.pdf - Power supply circuit diagram Microlab 350W
