Autoranging power supplies are essential in product development and functional testing for a wide range of electronic devices and systems. For example, the device under test (DUT) draws constant power under variable input conditions such as DC motor drives and regulated DC-to-DC supplies. In such circumstances, the ability of the autoranging power supply source automatically increases the current at lower voltages. It makes testing more flexible, enabling you to use only one power supply. The wider range of an autoranging power supply gives the test engineer flexibility to install the same power supply in a future test system if a new DUT has a higher voltage rating.
A DC bench power supply that does not have autoranging features requires you to use larger power supply or multiple power supplies under varying input voltage conditions. Using either approach can consume substantial amounts of capital and physical space.
Autoranging Power Supply Output Characteristics
Autoranging power supplies provide a greater range of operations than a typical power supply. To determine if a bench power supply has autoranging capability, look at the maximum rated volts, amps, and output power. If the maximum volts times maximum amps are greater than the maximum power, you have autoranging capability.
For example, Figure 2 illustrates the output characteristic of an autoranging power supply, V1 represents the maximum voltage, and I1 is the corresponding current such that I1 = maximum power / V1.
I2 represents the maximum current, and V2 is the corresponding voltage, so V2 = maximum power / I2.
The area along the curve is the voltage and current limited by the maximum power.
The maximum voltage (V1) for the output characteristic is 50 V, which can draw current 2 A because this is a 100 W power supply. The maximum current you can draw is 10 A at a maximum voltage of 10 V (V2.)
The ratio of V1 / V2 is 5, so this is a 5:1 autoranging. As this ratio increases, you have a more flexible power supply because it can operate over a wider range.
Autoranging Bench Power Supply Benefits
The most important criteria for power supply selection are the requirements for supplying the maximum necessary power, voltage, and current.
Testing may require a wide range voltage of operations — an autoranging power supply gives you more flexibility with a smaller power supply. For example, a system integrator aiming to build a flexible tester may be more likely to invest in an autoranging power supply to acquire additional flexibility. With this higher investment, you can get the same effectiveness with fewer components in a much smaller rack space, saving costs and resources.
Keysight carries a wide range of DC bench power supplies with autoranging capabilities. For example, the Keysight E36200 Series autoranging bench power supply can power devices that typically require higher output power with higher power ratings. A single output E36200 Series autoranging bench power supply can power devices requiring up to 200 W. A dual output supply provides two independent 200 W outputs that can combine into a single 400 W output.
If your testing requires higher power, the Keysight E36150 Series autoranging benchtop DC power supply provides more current and higher power at all voltages, offering test engineers higher levels of flexibility and more applications. The E36150, with 800 W of power on a single channel output, supplies up to 60 V and 80 A. These capabilities give you more usable power to meet your testing needs.
A bench power supply with autoranging capabilities enables a power supply to cover more applications without resorting to a larger power supply. Autoranging power supplies enable sustaining full power over a wider current and voltage range. You can evaluate more applications with one unit, especially electronic devices that require testing at different voltages and may need multiple voltages turned on and off simultaneously.
Autoranging DC power supplies provide flexibility for future test systems should a new product have a higher voltage range than current products. Consequently, an autoranging power supply can address an existing application and offer flexibility for use in future applications.
The design features of the E36200, and E36150 Series autoranging power supplies manage an extensive list of applications. Our wide range of autoranging power supplies gives you more current at every voltage level to support your future test needs.