MEASUREMENT AMPLIFIER

Diplomska naloga obravnava načrtovanje vezja merilnega ojačevalnika z dvema ojačevalnima stopnjama, katerima je možno nastaviti skupno ojačanje do 1000000. Ojačevalni stopnji sta realizirani z instrumentacijskima ojačevalnikoma INA-128. Podana je razlaga delovanja instrumentacijskega ojačevalnika ter kakšne so njegove prednosti v primerjavi z operacijskim in diferencialnim ojačevalnikom. Podane so sheme kako je vezje sestavljeno in katera so dodatna vezja, ki jih potrebujemo, da je delovanje ojačevalnikov natančno in da je njegov izhodni signal karseda uporaben za nadaljnjo uporabo. Opravljene so meritve na ojačevalni stopnji in predstavljene karakteristike končnega vezja, kjer so vidne podobnosti in razlike s podanimi proizvajalčevimi karakteristikami. Kot pomembni podatki naloge so skrajne meje, ki jih lahko dosežemo s takšno konfiguracijo vezja, meja šuma ter frekvenčna karakteristika.The thesis deals with design of the circuit measuring amplifier with two amplifier stages, which you can set the overall gain of the one million. Amplifier stages are realized by instrumentation amps INA-128. There is interpreted how the instrumentation amplifier works, and what are its advantages compared to operational and differential amplifier. There are electrical scheme of circuit, how is assembled and which additional circuits are needed for proper function of amplifire. This is circuit for adjusting offset voltage and power sorce which have very stable output voltage so there is no aditional noise. For amplifier are made different measurements of which they are presentet characteristics of the final circuit and similarities and differences between the manufacturers caracteristi