There’s a lot of debate out there over the merits of asking someone what they want for Christmas. Does it defeat the purpose of buying thoughtful gifts which show how well you know someone? Or does it accomplish the real goal of giving presents which are truly useful and desirable? Well, I personally don’t have a problem with being asked what I’d like for a present. Particularly when I can request, and receive, a sweet power supply like the Agilent U8002A:
Santa my parents were very kind to me this Christmas. Finally, more than 15 months after considering a handful of different supplies, I have one to call my own. And interestingly, it wasn’t one of the supplies I discussed in my original list. But I think it still meets my original set of requirements fairly well:
- Output voltage: 0-30V, 10mV resolution
- Output current: 0-5A, 10mA resolution
- Output voltage ripple: 0.01% + 2mV (5mV @ 30V)
- Output current ripple: 0.02% + 2mA (3mA @ 5A)
- Cost: $396
So far I’m very pleased with this supply. My multimeter indicates that its voltage and current readings are spot-on. This is no surprise though, considering that it came with a calibration certificate from Agilent. I also attempted to measure its output voltage ripple using my Red2 IOBoard, but quickly discovered that I didn’t have the necessary ADC resolution (in other words, the output was so clean I couldn’t measure any ripple or noise).
The interface on the U8002A is quite nice. Simple yet powerful. I particularly like the fact that I can adjust its voltage and current limits before enabling the output. This is one feature that would have been missing in most of the cheaper power supplies I looked at.
Just out of curiosity, I ran one more test while I had my IOBoard out and connected. I connected up a 20Ω resistive load and enabled the output while logging data:
That little cut in the voltage just before the output reaches steady-state is a little odd. Not that I’ve looked at a lot of PSU transient responses though. It just seems like the control is doing something strange there. Perhaps some sort of filter capacitor gets switched in and we hit a brief current limit? Who knows… It’s not a problem though. I’d be more concerned if the voltage had overshot the limit, but that’s clearly not the case.
Overall, if you’re looking for a PSU with specs like this one, I’d highly recommend the U8002A. It’s made by Agilent, so you know it’ll be a quality piece. And yet it’s reasonably priced (unlike most of their hardware). Let me know if you have any questions about it.