Built with a Renesas ISL81801 4-switch buck-boost controller. Uses 24V input. Output voltage is determined by an external DAC that wires into the feedback loop using a header pin. Output current is measured by a dedicated INA296 shunt monitor. The idea is to allow an external DAC/ADC to close the panel-emulation loop in real time by measure current, look up the I–V curve, and adapt DAC.
Lab-grade solar array simulators can easily cost USD 10,000. This is a JLCPCB-assembled board with the ISL81801 and 4 MOSFETs. External DAC/ADC is needed, which can be BenchPod (see BenchPod project on Hackaday).
Files
solar-array-simulator-schema.pdf
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08/24/2026 at 20:07
Did an initial bring-up of this board. All went well. I didn't connect Benchpod's ADC/DAC to it yet, as aI was first testing with 5V input and 3.3V DAC input to see if it's working properly. The INA measurements are a tiny bit off, because the resistors R25 and R26 are connected to the copper pour instead of traces, which adds some distortion. I should've just run traces for those 2 resistors instead of positioning them on the FET's copper pour with the shunt resistor.
All in all it works well and I'll continue testing, including with a real ADC/DAC (BenchPod's) to do a full solar cell simulation up to 48V (with 24V input).
I also realized I can use it as a battery simulator as well, just need to change the model in BenchPod from solar to battery and we should be good to go.