Power supplies of personal computers type ATX powerful, stable, and built on a pulse schemes, in the form of the finished unit in a metal case with the radiator and fan, they are light in weight. Besides, often buy very cheap or even almost nothing block disassembly morally outdated computer, and the price of the new block is not so high. Therefore, it is very it is tempting to use power supplies of personal computers in Amateur designs. For example, from 400-watt unit bus +12V can be a very good powerful enough to nourish the car transceiver in stationary conditions.
So, the litany ATX is a metal box with harness wires and panel with socket for connecting the power cord. On this panel sometimes the main power switch or connector cord monitor's power.
The wires in the harness are displayed on the four-pin connectors and one 20-pin connector. There may be other additional connectors. Flat 4-pin connectors bred red, black and yellow wires. Red is +5V, black is ground, yellow is +12 V.
20-pin connector coming out and other wires. Blue -12 V, -5 In white, orange and brown +3.3 V, crimson +5VSB for duty power. It has voltage when the power supply is switched off in standby mode, as well as other wire to communicate with the motherboard of a personal computer.
The ATX power supply can work outside of the computer. But when you enable it in the network the voltage will be only on the crimson wire +5VSB (standby power). To to enable the ATX unit in working condition necessary for it to run. For this purpose, 20-pin connector there is a green wire (point PS-ON). This wire you need to wire in General, that is, almost any black wire (just there is such in the neighboring pin 20-pin connector). The bloc runs and can be used to power something not a computer.
It should be noted that some blocks ATX, for example, to enable COMPAQ require circuit wire PS-ON +5VSB standby source. In General, start with circuit common. If the unit does not turn on, try shorting the PS-ON the duty +5VSB.
It is desirable to turn on the PSU without a load. Load something at least circuit +5V (red wire).
As for output currents, so it is usually written on a paper label on the casing. Depending on the power supply, the current through the circuit +5 V can be up to 50 And, on the circuit +12 V to 20 A. On circuits negative voltages the currents are small.
In some very old computers used power supplies AT, they ATX characterized by the absence of chains +3.3 V and duty +5VSB, and the lack during this mode, and the fact that they have "great connector" is not a 20 pin, and either 12-pin, or consists of two 6-pin connectors. By the color of the wires in General the same. To enable the block AT only need to apply the voltage. It should be remembered that there used to turn off a normal network the switch, which is mounted on the front panel of the system unit personal computer and connects to the four-wire power supply cable in insulating PVC tube. If there is such a cable, but the switch it is not hanging, then switch to connect or just jumper wire so that the voltage from the power terminal has entered a block diagram of (not difficult to understand). Typical circuit blocks ATX and AT shown in the figures.
Fig. 1. Pinout connector
Fig. 2. Typical scheme 200-watt ATX power supply
A typical diagram of the power supply AT
Author: S. Andreev