I need to add temperature sensors to my MC4X15A Motor Controller so I can monitor HEXFET temperature and cut the H-Bridges to protect the HEXFET’s. I have 2 analogue input’s designed for temperature sensors, but I also have a bunch of DS18B20 laying around. DS18B20 is a one-wire protocol device and you use it’s…
I need a load for testing and fancy a programmable load. My first idea was to use a resistor array and a relay operated switch board as illustrated below. Next as I looked into more intelligent techniques I also realize how easy it is to make one using a DAC and power transistors. The…
I don’t get much sense out from the INA210 at 0 – 2A. Firstly I realize that I use a far to large Shunt resistor. I use a 0.1R by mistake. 100mA would give 10mV that amplified with 200 should be 2V. At this size the Shunt become my weak point. At 3A it starts…
I fancied testing my MC4X15A motor controller as the driver for a PSU. The code is very simple as I bit-bang a PWM with 50% duty and use filter consisting of a 100uH coil and 1000uF capacitor. The result was quite good. I did however notice some input ripple. As I also scoped the Lab…
I am so far happy with the MC4X15A PWM channel with the exception of the current sensor. I have 3 more channels to solder up, so I will do the next without the low pass filter for comparison. I did not like the scope pictures, but will be interesting to see what I can do…
This model is not complete, but it gives an idea. I still lack the battery and the TF Card. The objective here is that I need a low cost CAN Adapter with Wifi to create an adapter that always work as an Analyzer as well.
These are the two different PSU’s used on MC4X15A – notice the supercap X20. I mounted a 0.33F Supercap for the purpose of keeping the MCU alive during powercut’s + act as a spike absorber on 3.3V. I am impressed – the PWM cut instantly, but Led’s and MCU keeps going for several seconds.
The first thing I noted was that my current readings went into negative voltage, so a bit research and I moved the ref pin 1 to ground – it seems to work better. I won’t know for sure before I activate the ADC and print readings. INA210 is supposed to have gain 200, but I…
These two scope pictures stunned me before I realized the mistake that stunned me even more. The first picture show HEXFET Output in yellow, Logic High/Low Cyan and Purple and BEMF voltage in Blue. The upper picture is with no load and the 2nd is with a DC motor as load. Why do my High…
This schematics show the PWM driver stage of MC4X15A. IRF7862 is rated at 17-21A continuous current and pulses as high as 170A, but yesterday I took out two simply because I replaced IR2103 with IR2101 and did not realize that the later have no short-cut protection – so the MCU switched on both High and…