Ever found yourself trying to build something only to find that the layout calls for an obscure resistor value that you don’t have on hand? Well this super simple hack is for you!
When starting out, I’d often find myself sitting down to start building something only to find that the layout I was building called a rarely used resistor value.
For example, a layout might call for an 820k resistor which you may not have on hand. You do, however, have a 390k and a 430k resistor. If you add 390k + 430k you get… 820k. So rather than run an 820k resistor you can run a 390k and 430k resistor in series to get a total of 820k.
What does running resistors in series mean?
Series basically refers to things that run after one another. When you see the term ‘running resistors in series’ it refers to taking two or more resistor and connecting them one after another. So the total resistance equals the sum of all the resistors connected together.
In the example above a 390k resistor connected to a 430k resistor provides a total resistance of 820k and can therefore substitute for a 820k resistor.
The image below shows how I’ve joined resistors to run in series. There may be a neater, more professional, way to do this but it’s worked for me. When connecting them this way you can drop them in to a PCB and they’ll stand about as high as an average capacitor. Just connect the wires at the top, solder and trim the excess wire. Easy.
