Category: Embedded Development

Lab PSU 0-30V / 10A – Part 2

In part 1 I created an analogue linear regulator that can be used stand-alone as is. But, the drawback with a linear regulator is that it regulate by splitting voltage out between the load and the transistors. This means that if you short-cut the load you have 36V * 10A = 360W heating up the…

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Lab PSU 0-30V / 10A – Part 1

I desperately need more lab PSU’s and I have a bunch of LM723 and TIP3055 transistors that are excellent for creating an old-fashioned Linear PSU module. Thinking a bit ahead I want to create the analogue regulator as a small, separate module with knobs on the front, heat-sink & transistors on the back and connectors…

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Water Detector

This drawing illustrate a water detector. A water detector is basically a standard ADC reading between two resistors where the 2nd resistor is a PCB as illustrated above. As the water raises the PCB will start leading current and the ADC reading will move from 3.3V to GND. This is the same principle as used…

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PLC Sensors and Actuators

One major issue is how to identify units in a network. I used STM32F030F4 on these and I absolutely love this little MCU costing 50 cent in TSSOP20 package, but it lack the serial number that is burned into other STM32 MCU’s. This serial number is crucial as it present a factory set ID allowing…

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PLC Cottage Surveillance

My grandparents passed away some years ago leaving a beautifully mountain farm behind. As no-one lives up there we have to leave the farm unattended for months at the time. This is a challenge in winter time as we fear the water pipes with freeze. The farm actually got internet installed so it is possible…

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On-Line Documentation

I just uploaded a design doc for the Universal Motor Controller on the downloads page. I used LibreOffice 5.3 since it could export to PDF, but believe me this is the last time I use that. I had so many problems importing drawings that I ended up importing everything to Word and then copy &…

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Universal Motor Controller

I designed this universal motor controller capable on driving DC-, Stepper-, BLDC- and even AC – motors earlier. The design parameters was 12-24V at 15A. This is quite a capable controller, but I did a mistake that limit the controller to 12-20V since I connected the Gate Drivers to the Motor PSU directly. To compensate…

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Fast ADC

The build in 12 bit ADC will give a resolution of 0.007V if I use it to control a 30V Lab PSU, so I was looking for something with a higher resolution. I did find something that could handle 24 bit @ 2.4Msps, but it required a NDA to see the price – I think…

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