I want to use a Voltage divider and i need to divide 5v to ~3.3 so I ordered 10K resistors on eBay, but the voltage divider needs a 20K and a 10K, can i use 2 10K's parralel as a 20K
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3 Answers
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Creating a 3.3 V voltage potential output from a 5 V voltage source using 10K resistors could be done using the following diagram of a simple voltage divider, using the following equation.
\$ V_{out} = V_{1} \cdot \frac{R_2 + R_3}{R_1 + R_2 + R_3} = 5 V \cdot \frac{20 k \Omega}{30 k \Omega} = 3.33 V \$
simulate this circuit – Schematic created using CircuitLab
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Two 10ks in parallel are equal to 5k, so if you did it that way your voltage divider would look like this:
answered Oct 18, 2014 at 17:53
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\$\begingroup\$ Both versions work, the difference is the current flowing through the resistors and the current you may draw from the 3.3V output. For example, if the load current is 50µA, first version provides 2.83V, second one 3.08V. \$\endgroup\$– GrabulCommented Oct 18, 2014 at 18:24
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\$\begingroup\$ How did you arrive at those numbers? \$\endgroup\$ Commented Oct 18, 2014 at 22:21
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\$\begingroup\$ 1st(series) : 5V - 10k*(5V/30k + 50µA) = 2.833V , 2nd(parallel/series) : 5V - 5k*(5V/15k + 50µA) = 3.083V \$\endgroup\$– GrabulCommented Oct 18, 2014 at 23:06
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Two 10Ks in parallel make 5K. For 20 K, you need to connect them in series.
answered Oct 18, 2014 at 15:50