Lab Power Supplies: 5 Things To Consider When You Invest In Them

The lab power supplies are used so that they can act as a voltage regulation or current regulation power supply. The range of voltage regulation is from 0V to 30V and the range of current is from 0A to 5A. The output by these power supplies are set by the rotary switches with the value displayed on a LCD display. These lab power supply products have low ripple and noise and high reliability as well as high accuracy.

To choose the best or most appropriate lab power supply for a particular application, one must determine the answers to certain important questions and understand the basics of how power supplies are specified. So while looking for a lab or bench power supply, a person must consider some of the important points in order to save substantial time as well as money in the system configuration process.

Things to consider while investing on lab power supplies:

1.Power, voltage and current requirements for the devices which are under test

The power envelopes vary from one power supply to another. In the rectangular power envelope type of supply, any load current is supplied which does not depend on the voltage level.
Another variety has multiple rectangular envelopes for various ranges of voltages and that also offers the option of higher values of one perimeter at the expense of another perimeter.
Then there are those which are capable of delivering hyperbolic envelopes that provide even more continuous transition than multi-range power supplies, in this kind of power supply, one parameter is inversely proportional to the other parameter. The high-power output supplies tend to have either a multi-range or a hyperbolic envelope.

2. Parameters
Accuracy: The accuracy provides the information regarding the closeness between the regulated parameter and its theoretical value. The uncertainty in output is mostly because of error terms in case of digital-to-analogue converter (DAC). The accuracy of the setting is tested by measuring the regulated variable with a traceable, precision measurement supply that can be connected to the output of the power supply.

Resolution: The smallest change in voltage or current setting that can be selected on power supply is known as resolution. The different specifications of resolution, can limit the number of discrete levels that can settle, a DAC which has more bits can produce finer resolution.

But the resolution can be less than the number of bits in the DAC if there is any requirement of correction for offset and gain errors. Setting resolution is either expressed as an absolute unit value or a percentage of full value.

Accuracy of readback: This provides the information regarding how accurate the internally-measured values are compared to the theoretical value of the output voltage.

Stability: The performance of the power supply will change inevitably as it ages. So you must choose a lab power supply which can work properly for a longer time period and for maintaining long term stability regular verification and calibration is required.
Temperature stability: There is a specific temperature range between which the accuracy of power supply is specified. The temperature generally ranges between 20 degree C and 30 degree C.

3. Required output accuracy level: It is important for an individual to review the power supply’s output accuracy and readback specifications for the accurate control of the voltage at the load for experimentations of researches or even characterizations of devices.

4. Level of noise in the systems output: Noise from any external source might cause problems for very low voltage circuits that use or measure very low currents such as transducer detectors. The power supply itself creates a lot of noise and the noise breaks down into two modes which are normal mode and common mode. So, in case there is a requirement for minimizing noise, choose a power supply based on the power requirements.

5. Number of outputs required: There are some applications that require sourcing of more voltage or current beyond the capacity of single output, some parallel outputs are allowed by some multi-output power supplies. To ensure flexibility, look for a multi-output power supply with isolated outputs.
These are some common things that need to be considered while investing in lab power supplies.

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