ADWSystems
Member
Long story short. I need to build a load bank of variable load. I was thinking R2-R ladder style with SIP SPST relays would do nicely. I even have (had) everything laid out on the PCB. Then I went to find the parts numbers for the resistors. Problem is 5% resistors have nominal values 10% apart. The first load is 100 ohms. Great they (actually) make that value. 50, 25, 12.5, etc. they don't. They don't have values that are 2x apart from each other. I considered just buying a bunch of 100 ohm resistors and paralleling them, 1, 2, 4 OK. 8, I supposed. 16 and 32, I don't think so.
Question to the lot, how would you go about making an R2-R ladder from standard resistor values? (1/2W resistors, avg 5% precision)
Question to the lot, how would you go about making an R2-R ladder from standard resistor values? (1/2W resistors, avg 5% precision)