Power supplies to pair with Joulescopes

The Joulescope JS110 is a measurement instrument only. Most people add the Joulescope JS110 to their existing setup using whatever battery or power supply they usually use. On several occasions, we have been asked to recommend power supplies. I don’t have any strong recommendations, but I have provided guidance.

Joulescopes work with most power supplies, which can be a battery or bench supply up to +15V. You need to ensure the power supply has lower voltage and current noises than what you want to measure. Pure switching power supplies are generally too noisy for most Joulescope customers. The power supply can generally be a switching power supply as long as it has a linear regulator output.

Things to consider:

  • Maximum voltage
  • Maximum current
  • Voltage & current noise
  • Isolation (I typically recommend isolated supplies. It is easier to form ground loops with non-isolated supplies accidentally. Isolated supplies mean you have one less thing to worry about)
  • Size / portability

For an inexpensive bench supply, you can consider the Siglent SPD3303X or Rigol DP800. If you are looking for an inexpensive, more portable supply, we have a few happy customers using the MiniWare MDP-P905 with a low-noise adapter, like the iPower LN-0530. You can also use a USB battery pack for a fully portable setup with controlled output voltage.

What do you use and recommend?

I can recommend an expensive one :wink:

We use the Keithley 2280S-32-6 Precision DC Supply and its more capable sister, the 2281S-20-6 Precision DC Supply & Battery Simulator.

They can measure load current in the nanoamp to 6A range with high precision, so they demonstrate what a good job Matt did with the Joulescope!

They are benchtop units, but very heavy. The 2281S battery simulator is great, because you can generate a model of a rechargeable battery, then just use the simulated battery from that point forward - great for assessing your device performance under low battery conditions. You can set the unit to any state of charge and either run it dynamically (simulated battery depletes) or statically. The 2280S is identical except no battery simulator.

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