MEP EP#240: Disturbed Solder Accuracy
Parker
Got a fully automatic screen printer!ESE US-2000XPotentially lower our minimal paste sizeTwitch Live Stream podcasts?Amazon multimeter probesHigh voltage low current measurementDon't want to break the connection so a traditional ammeter isn't going to workSticking with the read both sides of a resistor methodCaddock 1776-C681 high voltage high resistance high tolerance divider1/100 so 0 to 500v becomes 0 to 5vADC - MCP3551-E/SN22 bitSPI2.4 meg ohm input impedanceIdeally the voltage divider has a “gain” of 0.01 but if the ADC is directly attached to the divider the gain is around 0.0096Full scale would be 4.8V instead of 5VSolution: add a bufferAD8244BRMZQuad buffer Typical offset voltage of 100uVGain error of 0.03% max on +/-15v rails 10T ohm and 4pf input resistance/capacitance - 10^12Gain error is now 0.009999999901 - Close enough