The AIM-TTI QPX750SP is a powerful bench power supply, capable of providing a maximum of 750W DC power within a wide voltage range of 0-80 V. It is a professional instrument I got for testing as part of the AIM-TTI Bench Power Supply RoadTest.

This blog post is the 1st one from a series of blog posts, in which I will try to thoroughly evaluate the unit.

With this occasion, I would like to thank AIM-TTI and Element14 for providing this power supply. I'm confident it will be very useful for many of my future projects.

1. Motivation

A good bench power supply is an essential tool of an electronic hobbyist.

Most hobbyist (including me ) however do not pay too much attention on what (bench) power supply they are using.

For example, I usually choose one of the bellow "power supplies" depending on the needs:

• RD Tech DPH5005, a relatively cheap 50V / 5A current limited DC-DC buck-boost power supply
• old ATX power supply converted to bench supply, providing 12V, 5V and 3.3V DC
• various 12V DC adapters
• various power adapters for laptops, usually 16-19V DC
• 3.3V and 5V generated with a random Arduino board
• LiPo batteries connected in different configurations

Now, the above "power supplies" are either low-end bench power supplies, or not suited for testing / development purposes at all. The reason I still use them is that probably I do no really understand (yet) the limitation of the above supplies, and the benefits of a decent bench power supply.

The AIM-TTI QPX750SP Bench Power Supply will be an ideal replacement for my collection of low-end power supplies. The QPX750SP has way better specs than all of the above "power supplies". Additionally, it has some features like LAN (LXI) and GPIB interfaces, which allow some interesting application featuring remote monitoring / control.

My goal for this Road Test is to gain general knowledge about power supplies, and also help other hobbyists to do so.

The plan for this road test is to do a practical comparison between the AIM-TTI QPX750SP Bench Power Supply and my collection of dubious "power supplies".

2. Power Supplies

As I mentioned earlier, the AIM-TTI QPX750SP will be tested against my collection of "bench" power supplies, I usually use to supply power to my projects.

So, here is the list of power supplies I will evaluate in this road test:

Power Supply	Description
AIM-TTI QPX750SP	Single output lab DC power supply with a maximum power output of 750W.   Voltage: 0 - 80 V Current: 0 - 50 A Power: 0 - 750 W   Operating Modes: constant voltage (CV), constant current (CC), constant power (CP)   Features: over voltage protection (OVP), over current protection (OVC) LAN and USB connectivity (product page)
RD Tech DPH5005	Lab supply / DC-DC buck-boost converter with a DC input.   Voltage: 0 - 50 V Current: 0 - 5 A Power: 0 - 250 W   Operating Modes: constant voltage (CV), constant current (CC)   Features: optional USB / Bluetooth connectivity   (product page)
Modified ATX Power Supply (Premier LC-8460BTX)	ATX power supply modified to be used as a primitive lab supply.   Voltage: 3.3, 5, 12V, -12V Current: 22 / 15 / 16 A (max)   Specs:
IBM Laptop Charger / Supply (16V)	Voltage: 16 V Current: 3.36 A (max) Power: ~ 54 W (max)
ASUS Laptop Charger / Supply (19V)	Voltage: 19 V Current: 3.42 A (max) Power: ~ 60 W (max)
Mean Well Power Adapter (12V)	Voltage: 12 V Current: 2.5 A (max) Power: ~ 30 W (max)
LiteOn Power Brick (19V, designed for NVIDIA)	The power supply of a Jetson AGX Xavier development kit.   Voltage: 19 V Current: 3.42 A (max) Power: ~ 60 W (max)
LTE Power Brick (12V, designed for Xilinx?)	The power supply of a Xilinx ZCU104 evaluation kit.   Voltage: 12 V Current: 5 A (max) Power: ~ 60 W (max)
Arduino Like Boards	Commonly used to provide 3.3 V and 5 V for testing.   Voltage: 3.3 / 5 V Current: ~ 1 / 1.5 / 2 A (max)
LiPo Battery (Turnigy Bolt 1800)	High performance LiPo battery with 4 cells and a 1800 mAh capacity.   Voltage: 15.2 V (17.6 V fully charged) Current: 65 - 130 C (~117 A continuous / 234 A peak)

3. Dummy Loads

As you may have already guessed, I don't have a programmable electronic load to properly test these power supplies.

Instead, we will use a set of DIY loads to simulate different kind of devices that could be powered with a power supply:

4. Test Equipment

To examine the power supplies behavior under different conditions the following test equipment will be used:

5. Test Plan

The Road Test review will consists in multiple blog posts and the final road test review.

The Road Test will focus on different aspects of the power supplies, and they will also include experiments targeting:

• operating modes - constant voltage, constant current, constant power
• output ripple and noise
• settings resolution - voltage, current
• protections - over voltage, over current, short circuit
• load handling characteristics - resistive / inductive / capacitive loads, dynamic load
• etc.

The next blog post will focus on behaviour of the tested the power supplies under static loads (resistive / inductive / capacitive). Then, the following blog posts will focus on aspects like dynamic load handling, protections, and others.

In the final Road Test Review I will do a recap comparison between the tested power supplies, and I will also take a look on the different features of the AIM-TTI QPX750SP.

Stay tuned!