Voltage Divider

This is one of the most fundamental circuits in electronics and is our most often used calculator. We find it handy in determining the feedback resistor values for switching power supplies.

Inverting OpAmp

Widely used in audio circuits as well as conditioning signals for A/D converters, this circuit will output a negative voltage if a positive voltage is applied or a positive voltage if a negative voltage is applied. The magnitude of the output voltage is determined by the resistor values.

Noninverting OpAmp

Similar to the above circuit but you get a positive voltage output for a positive voltage input. The magnitude of the output voltage (or gain) is determined by the resistor values.