How does an unregulated DC power supply work?
Very basic DC power supplies, called unregulated, just step down the input AC (generally the DC you want is at a much lower voltage than the wall power you plug the supply into), rectify it to produce DC, add a output cap to reduce ripple, and call it a day. Years ago, many power supplies were like that.
How is the output voltage of a DC power supply determined?
In these kinds of supplies, the output voltage is dictated by the turns ratio of the transformer. This is fixed, so instead of making a fixed output voltage their output is mostly proportional to the input AC voltage. For example, such a “12 V” DC supply might make 12 V at 110 VAC in, but then would make over 13 V at 120 VAC in.
Can a DC power supply be used in a computer?
A DC power supply can be hard to find and expensive. With features that are more or less hit or miss for what you need. In this Instructable, I will show you how to convert a computer power supply into a regular DC power supply with 12, 5 and 3.3 volt outputs. For about $10! Why use a computer (ATX) power supply?
What’s the minimum load for a DC power supply?
Some power supplies, generally older switchers, have a minimum load requirement. This is usually 10% of full rated output current. For example, a 12 volt 2 amp supply with a minimum load requirement of 10% isn’t guaranteed to work right unless you load it with at least 200 mA.
What to do if your power supply is fluctuating?
If the problem is with your property wiring or equipment, you’ll need to pay for it to be repaired. Our qualified electricians can come and inspect your wiring and advise on the causes of fluctuating power supply. In many cases, a loose or poor connection can be the issue and can be fixed while we’re on site.
What causes a power supply to malfunction?
High voltage and current surges can be the cause of multiple component failures, including fuses, bridge rectifiers, diodes, and FETs. Even if the PSU is equipped with an MOV (surge protection) and an NTC thermistor (inrush current protection), it can still malfunction, especially if the voltage or current surge is too high.
Why is my DC power supply in CV mode?
Upon powering a DC power supply of this type, with nothing connected the default mode should be in CV mode. This means that the power supply will have voltage control of the output power. These power supplies also allow you to set a current value, which is often referred to as the current limit.
What happens when power supply exceeds input voltage?
If the input voltage decreases to the point where the power supply drifts into this region (known as the capacitive region), the power supply can malfunction or fail completely. Some non-isolated converters, including the boost converter used in a PFC circuit, only converts in one direction, up or down.
Why does a DC-DC converter need to be adjusted?
For instance, many microprocessors can operate at a low voltage to save power, and then operate at a high voltage for increased processing power. Switching between these operating modes requires adjusting the output voltage of a DC-DC converter.