Timeline for Change input reference to 1 - 5 V
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 23, 2015 at 3:24 | comment | added | Russell McMahon | Use a 2nd opamp section to make a unity gain buffer (OA out to OA-) use this to buffer a pot that you adjust to 1V (Pot feed OA+,OA out to V1. ) || Make One of the R3's adjustable using a bigger value pot than R3 fixed. eg if R3 = 10K make pot say 15K so you can adjust it either side of 10k slightly. This is used to make gain of V1 & V2 inputs track. || Overall accuracy is limited by balance of resistors so use 1% or better still 0.1%. (may not need pot above if R's are matched well enough). IF you want to avoid having to supply matched R's buy an "instrumentation amplifier" IC. | |
| Jun 22, 2015 at 13:00 | comment | added | Majenko | 0-4v is 1-5v with 1v subtracted as the answer says. V2 is your signal at 1-5v, v1 is 1v reference voltage. V1 is subtracted from V2 (so 1-5 becomes 0-4) and then amplified by R3/R1 to make 0-4 into 0-5. | |
| Jun 22, 2015 at 11:55 | vote | accept | KoenR | ||
| Jun 22, 2015 at 11:54 | comment | added | KoenR | I like the differntial amplifier answer. But, what are V1 and V2? Why are you talking about 0-4 to 0-5 when I have a 1-5? Thanks in advance! | |
| Jun 22, 2015 at 10:44 | history | answered | Joris Groosman | CC BY-SA 3.0 |