Using voltage regulators
Simplified DIY Transformers for tubes
DIY Transformers
250v + 6.3v for valves.
PIC DC/AC MkIII
PIC DC/AC MkII
Charger/PSU
PIC based DC/AC
Push-pull inverter
DC-AC 10W-1KW
Alternative Power
1-off timer
Voltage converter
Easy PSU
Bench PSU
Simple PSU.
NiCad charger