Archive of posts from March 2023

  • Solar Panel Project Update - Part 3

    In my previous post I explained how I improved the accuracy of my DC sensors using ADS1115. But there is one problem though. The ADS1115 gives accurate reading even when the supply voltage keeps changing. Yet, the sensor values will not be correct. The reason is that if the supply voltage is changing, the reading on the sensor will also change, but the accuracy of the reading will be stable because ADS1115 is independent of power supply voltage fluctuations. For example, let’s say the supply voltage is 2.5V, then when there is no current, the DC current sensor will read 2.5V, and in the code we assume the current is 0 at 2.5V. Now if the supply voltage drops to 4V then the sensor will read 2V, which is still the mid point and indicates 0 current. But in the code we have a hard coded number that 2.5V is the midpoint and we mistakenly assume that some current proportional to -0.5V is passing through the wires. That is the problem.

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  • Tax Loss Harvesting

    There are lots of legitimate ways to reduce taxes and tax loss harvesting is one of them. However, in practice, it is much harder to execute. But before we get ahead of ourselves, let me explain what tax loss harvesting is in case you don’t know. Tax loss harvesting is nothing but selling your investments for a loss when the value is below your invested amount. Then use the losses to offset any other capital gains or income that you might have. Generally tax loss harvesting works well with equity markets because there is a possibility that the markets fall and your investments could be worth less than what you invested.

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  • Solar Panel Project Update - Part 2

    This is a continuation of my previous post giving updates about my solar panel setup. As you will probably remember from that post, I found a good sensor that would measure AC voltage and current accurately and I was satisfied and very confident about the data coming from the sensors. However, I cannot say the same about my DC measurements. Many components in the system should be measured in DC including solar panel current, battery voltage and current etc. My initial set of sensors were not accurate and used to drift quite a bit with supply voltage and ambient temperature. So I set out to find better sensors and upgraded them and I cover part of that story in this post.

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