Interesting facts and frequently asked questions about power soures, laboratory power supplies and laboratory power supply units
Power supplies, which belong to the power sources, supply a defined current, as the name suggests - the opposite of which are electronic loads or drains that consume power.
Unlike a normal power supply unit, a laboratory power supply unit has certain characteristics that set it apart. Put simply, compared to simpler power supplies, a laboratory power supply offers more setting options and enables a more flexible range of use.
As a rule, the output voltage and the current limitation can be adjusted. Furthermore, they have analogue or digital displays for output voltage and current. In addition, they have a display for the set current and voltage values.
Advantages of laboratory power supply units
As a rule, a high-quality laboratory power supply unit is characterised by the following features:
- Higher accuracy of the displays compared to usual power supplies
- The output(s) are normally protected against overload and short circuit
- They have an output that can be switched off
- Limit values for current, power and voltage can be set
- Voltage and current curves can be programmed
- An interface that enables control via PC
- A master/slave function that can be used to connect several units in series or parallel.
Where is a laboratory power supply used?
Laboratory power supplies are usually used in electronics development or in the testing and service sector. But the laboratory power supply is also frequently used among ambitious hobby electronics enthusiasts.
We distinguish the categories 0-100 V for lower power, up to 1000 V for more demanding applications, followed by most powerful devices up to 1 kV for use in electronics development.
What is meant by an adjustable power supply?
Adjustable or controllable power supplies offer the possibility to individually adjust the output voltage via a voltage regulator. Usually this amounts to 0-30V, but other max. output voltages are also possible with various adjustable power supplies.
Are laboratory power supplies controllable?
Laboratory power supplies always have a controller, so they are basically controllable power supplies. The output voltage (e.g. 0 - 30 volts) can usually be regulated, but in most cases the output current can also be regulated.
Current regulation in laboratory power supplies
High-quality laboratory power supplies are usually characterised by the fact that, in addition to voltage regulation, they also have current regulation (e.g. 0 - 5 A).
What is the difference between switching power supplies and linear power supplies?
What is the difference between a linear power supply, also called a transformer power supply, and a switching power supply? Each of these types of power supplies offers advantages and disadvantages that make them practical for the particular application.
Linear power supply
The linear power supply is technically simpler. First of all, the AC voltage is reduced to a lower value via a transformer. Then the AC voltage is converted into DC voltage and the energy is buffered. Finally, the voltage can be stabilised at a target value.
The advantages of a linear power supply are its simple construction and the fast and precise regulation of the output voltage. In addition, hardly any interference suppression measures are necessary.
The disadvantages lie in the size of the power supply unit itself and the size of the built-in transformer. As a result, they are bulky and heavy and have very high energy consumption.
Switching power supply
The more complicated switching power supply stores the AC voltage in a capacitor after rectifying it. Then an electronic switch supplies a small transformer with current in pulses. This leads to the DC voltage becoming AC voltage again, which is transformed in a transformer.
The voltage is filtered and stabilised via capacitors.
The advantage of a switching power supply is that it allows for a more compact design with the same energy and thus has less weight. At the same time, they are more effective and economical in terms of energy consumption. Disadvantages are the more complex circuitry and the higher sensitivity to high-frequency interference. Smaller irregularities quickly become noticeable as a disturbance at the output.
Power supply, power supply unit and co.
Terms such as por supply and power supply unit are often thrown together, usually used synonymously, which can lead to confusion here and there. One speaks of a power supply in the case of simple "plug-in power supplies", such as those that come with a certain electronic device. This usually only provides a certain output voltage (such as 6V or 12V) and an output current. A power supply unit, on the other hand, is a more sophisticated device, for example, one in which the voltage can be adjusted.
The term “power supply”, or PS for short, is also frequently used. This can be translated quite simply as power supply unit.