A simple voltage converter built with a 555 timer can be made using this electronic circuit diagram. Since the converter does not contain any adjustable element, output voltage is, dependent of load. Theoretically, the output is twice than the input voltage, but, because losses can not reach this level. The main losses occur in semiconductor junctions of transistors and the rectifier diodes
IC1 oscillator generates a signal frequency of about 10 kHz, depending on IC1's output level T1, or T2 is in conduction.
Circuit does not contain critical components: IC1 can be any version of 555, bipolar or CMOS, while transistors are cheap low-frequency types.
Converter consumes a current of 5 mA (555) plus twice of the input power.