Negative voltage from multi-tap transformer
Is it possible to use two of the taps to generate negative voltage and use other taps for positive voltage?


Not that way.



Figure 1. The common GND on the two rectifier outputs places a short-circuit on the transformer via two rectifier diodes.







simulate this circuit &ndash; Schematic created using CircuitLab

Figure 2. Two standard ways to do it. (a) Half-wave rectification. (b) Bridge rectification.