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  • Turn 9V Battery to 5V Battery (simplest and cheapest way)

    No.(Well, maybe just in an emergency, for some short calls.)Take a phone battery - a common one like the iPhone 5s has a capacity of 1560mAh.Even a (very expensive - like 10US$ apiece) lithium 9V battery has only 1000mAh (the fact that it has 9V instead of just 5V doesn't matter, those 4 volts get converted to heat by the regukator...) an alkaline battery is more like 500mAh and a zinc-carbon like 250 mAh...And don't forget that the regulator has no heat sink at all. Remember those 4V voltage difference? Multiply the current needed (and a charging smart phone may want like 2A) with thos 4V to get the power this teeny tiny regulator has to convert to heat. Any more than 200mW (or 50mA) - I'm just guessing here as the data sheet says nothing about the IC in mid air - will probably fry the...

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    No.(Well, maybe just in an emergency, for some short calls.)Take a phone battery - a common one like the iPhone 5s has a capacity of 1560mAh.Even a (very expensive - like 10US$ apiece) lithium 9V battery has only 1000mAh (the fact that it has 9V instead of just 5V doesn't matter, those 4 volts get converted to heat by the regukator...) an alkaline battery is more like 500mAh and a zinc-carbon like 250 mAh...And don't forget that the regulator has no heat sink at all. Remember those 4V voltage difference? Multiply the current needed (and a charging smart phone may want like 2A) with thos 4V to get the power this teeny tiny regulator has to convert to heat. Any more than 200mW (or 50mA) - I'm just guessing here as the data sheet says nothing about the IC in mid air - will probably fry the chip.This circuit may be okay for small loads - a few 10s mA - but keep in mids that the data sheet states a minimal load of 10mA for a stable regulation...

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  • verence commented on 7q2's instructable How to Tie Your Shoelaces2 years ago
    How to Tie Your Shoelaces

    Or do it like this guy.

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  • verence commented on Hafsah Aamer's instructable The Diameter Puzzle2 years ago
    The Diameter Puzzle

    Why so difficult? Fold the circle in half - done. Doesn't even need a pencil ;-)

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  • How to Find Smallest and Largest Number in Array

    What are your tmp variables for? The are not used anyhow.Start your loop with the second element. The first one is already in small and large.for (int i = 1; i < arr.Length; i++)Why a second loop through all of the array to count the appearances of the smallest value? Do it in the first loop.if (small > arr[i]) { indexAmountSmallestNumber = 1; small = arr[i];}else if (small == arr[i] indexAmountSmallestNumber++;In that case, you'll have to initialize the indexAmountSmallestNumber to 1.Getting arr[i] four or more times can be costly. Get it once into a temporary variable and use that, or use a foreach loop.Remove your comments. They are less than helpful. For example://large == 4, arr[i] == 5Well, maybe the one time you checked it in the debugger. But will that help you to unde...

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    What are your tmp variables for? The are not used anyhow.Start your loop with the second element. The first one is already in small and large.for (int i = 1; i < arr.Length; i++)Why a second loop through all of the array to count the appearances of the smallest value? Do it in the first loop.if (small > arr[i]) { indexAmountSmallestNumber = 1; small = arr[i];}else if (small == arr[i] indexAmountSmallestNumber++;In that case, you'll have to initialize the indexAmountSmallestNumber to 1.Getting arr[i] four or more times can be costly. Get it once into a temporary variable and use that, or use a foreach loop.Remove your comments. They are less than helpful. For example://large == 4, arr[i] == 5Well, maybe the one time you checked it in the debugger. But will that help you to understand the code in two years? Good comments do not say, what the code does - good readable code does this itself. Good comments tell you why it does it this way.

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