Learn these transformerless power supply circuits, use a capacitor instead, it smaller and lighter than transformer. There are circuits as follows.
Dual DC Regulator using +12V, -12V and Ground output
Multi voltage power supply circuit. There is 2 Dual output, The 12V are +12V,-12V, Ground. And also the 5V are +5V, -5V, Ground. All 1A max.
See two negative Voltage Regulator circuit ideas. Do you know? we can use PNP transistor and Zener diodes in these example circuit 12V,9V at 700mA output