ZS1100A Power Meter

by ZSCircuits

A USB-based power supply that can accurately estimate the energy consumption of IoT devices

View all updates Sep 14, 2020

Rev4 Boards Recieved, Tested, Minor Bugs Fixed

by Prajay Madhavan

We received the assembled Rev4 boards which had some changes made to fix bugs and some additional features. Based on the tests performed so far, the changes work as expected.

The following features and performance have been tested:

  • Programmable output resistance: Checked the change in the output resistance from near 0 to about 10 Ohm. The output shows a linear drop with the output current with the slope equal to the output resistance. No stability issues seen as the resistance setting is added in the feedback loop

  • Output over voltage protection: If the output voltage goes above 7.2V, the protection circuits kicks in and turns Off the output relay. This ensures that the tool is protected from external high voltages. Short spikes of high voltage are suppressed by ESD protection

  • Output current limiting: The output current limiting feature is tested from limits ranging from 50mA to 2A and seems to work fine. The output remains constant till the limiting current and beyond that limit, the voltage drops off rapidly to clamp the output. This keeps the current at constant levels.

  • Short circuit protection: The output gets automatically cutoff when a short circuits is detected (current > 2.5A).

  • Reverse current protection: Checked the feature and does as expected.

Based on these tests, we have made some minor modifications to the final PCB and BOM.

We will order the final set of boards shortly and start the assembly for the final delivery in the coming weeks. We will get one prototype for EMI tests in the meanwhile.

If all goes as per plan, we are just in time to make the deliveries in the middle of Oct 2020.

About the Author

Prajay Madhavan

$12,024 raised

of $11,000 goal

109% Funded! Order Below

Product Choices


ZS1100A Power Meter

One ZS1100A, two banana-to-alligator clip cables, eight jumper wires for the front-facing I/O, a USB cable, a flash drive with software, and a quick start guide. Power supply sold separately.


AC-DC Switching Power Supply

From the Crowd Supply Basics project.

Switching Adapter, Level VI, Desktop, 70 Watt, 90-264VAC Input, ITE & Industrial, 15VDC Output, 5.5x2.1x12mm, Straight, DC Cable 1220mm. By Cincon.



Main area of expertise are Electro-magnetics, RF & Mixed signal board designs, RF test and characterization, Debugging board level problems like spurious emissions, noise coupling analysis, Noise reduction in electronic Systems. In addition we design software and firmware solutions for our products.

Prajay Madhavan

Mouser Electronics

Component Provider


PCB Assembly

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