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  #45748 Posted 1 Year, 4 Months ago
27ace27
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what is the formula? like if 3V before a 150K resistor, how many volts would there be after the resistor?
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  #45773 Posted 1 Year, 4 Months ago
njorange
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You do not have enough information. you would need to know the resistive load. In your example if RL is load then the voltage following the 150K resistor would be 3V x RL / (150K + RL)
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  #45785 Posted 1 Year, 4 Months ago
27ace27
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how do you calculate load?
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  #45814 Posted 1 Year, 4 Months ago
njorange
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You have to know the load to calculate the voltage drop. It might be specified or you could measure it with a resistanace meter. If you don't have a resistance meter you could probably calculate the load by putting different series resistors and measureing the voltage drop. This would only work for a purely fixed resistive load. Loads like a light bulb would change with different voltage applied.
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