AC / DC - Power Supplies

DC-Power Supplies / Voltage Sources

The spectrum of DC power supplies ranges from simple power adapters with only one output voltage to complex controllable power sources. Power adapters, often also called plug-in mains adapters, are mainly used for small electrical appliances (such as telephones, strings of light, notebooks, etc.) in private households. They are included in the scope of delivery of the product and only serve to supply power with a defined output voltage of 6 V or 12 V, for example. The output power is usually limited to < 200 W due to the simple design.

The range of more powerful power supply units extends from the handy desktop unit to units designed for installation in 19” racks.

They have

  • adjustable, constant output voltage (CV) or
  • a constant current (CC).

Depending on the application and configuration, these two operating modes alternate at different loads; this is called crossover operation.

The input and output values can be set and read exactly via a display. For universal use in the industry, these power supply units are often equipped with multiple channels and can be combined with each other. Therefore, output voltages of several kilovolts and output powers in the megawatt range can be realised in parallel operation.

You will find an extremely powerful DC power supply product series in our shop, for example, in the programmable MT product family by Magna-Power.

Basically, a distinction is made between clocked and linear regulated power supplies.

With linear power supplies, the alternating voltage is transformed down to a smaller value via a transformer, rectified and stabilised. The advantages lie in the technically simple design. In addition, hardly any interference suppression measures are necessary. The disadvantages are the size and weight of the transformer. This makes them unwieldy and heavy. The efficiency is very low because a lot of energy is converted into heat under load.

In switched-mode power supplies, the rectified input voltage is converted into a higher frequency (typically 10 to 300 kHz) by means of a switching regulator (chopper) and then transformed to a lower output voltage by a transformer. Due to the higher frequency, a smaller transformer can be used for the same power. Therefore, switched-mode power supplies not only have a considerably more compact design, but also have a higher efficiency due to lower power consumption. After the transformation, the AC voltage is rectified and stabilised again. However, the more complex circuitry and the associated greater probability of failure have a disadvantage. The higher sensitivity to mains irregularities, e.g. surge/burst events, quickly become noticeable as a fault at the output.

AC-Power Supplies / Voltage Sources

AC power supplies usually provide a sinusoidal output signal. Due to variably adjustable frequencies, these voltage sources are used for testing devices that are used worldwide and must comply with certain country-specific standards.

With multi-phase AC sources, the angle between the individual phases can also be varied. In addition, network disturbances, e.g. voltage fluctuations (dips) and voltage interruptions (interrups), as well as abrupt changes in voltage, frequency or waveform, so-called transients, can be simulated. Therefore, all existing power supply systems worldwide can be simulated.

For testing avionics equipment, special AC sources have been developed that can cover a frequency range in the kHz range.

At LXinstruments you will find a wide range of AC power supplies from various manufacturers, e.g. the high-precision, programmable high performance laboratory power supply by APM Technologies: Programmable AC Laboratory Power Supply | 5000 V.

This is how you can reach us directly:

Klaus Diederich
Christian Korreng

Mail:
Tel.: +49 (0)7032 / 895 93-0