Read (https://forktestlab.com/p-t)
If the energy usage of your device is very low, it is easiest to assemble a linear voltage stabilizer from literally two parts: the OA and the transistor. And use analog Fork output as a reference voltage.
This solution will allow the voltage to be adjusted between 0 and 10V. Maximum power is limited by the capabilities of the VT1 transistor and its cooling.
In our case, the debugging board STM32F0 is the test device. Its consumption/energy use is no more than 70 mA. Thus, the transistor will generate about 0.7 watts of heat, when it's powered by the 12V.
To control the serviceability of the device and possible short circuits - we will add a current-measuring shunt to the "ground." This, of course, reduces the actual supply voltage of the device. But with quite little resistance of the shunt, this influence is slight. In our case, the drop on the shunt will not exceed 70 mV.
For illustrative purposes, we have assembled a layout with UTC324D (LM324D analog) and 2SD882P.
The testing program gradually increases the supply voltage in 0.1V increments/pace. The R1 shunt voltage is then measured and if the threshold is exceeded, the power is cut out and the testing is over.
In order to reduce the impact of noise and random spikes of consumption, the RMS is measured over 16 dimensions rather than instantaneous current values.
As a result, the oscillograms obtained during debugging show how the voltage increases. In the range of about 2V, the tested device tries to start up, but there isn't enough power for that.
If the voltage is further increased, the debugging board goes into operation mode. Increases in consumption are visible when the LED is turned on.
And in case of short circuit (laboratory PU there is limited of maximum current: 150mA) the power supply is cut out.
The source code of the test program is available at this link.
Thus, using Fork and 3 additional parts, we have assembled a simple, and at the same time convenient stand for automated testing of the device power supply system with failure monitoring. In case if you have bunch of devices, this will save your time.
Read more https://forktestlab.com/
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