LM317 based voltage converter to get the voltage of ±5V from the input voltage of ±12V.
http://www.hobby-elec.org/e_ckt21.htm
The input voltage is +5 V, the output voltage is +30 V and can get the about 20-mA output current.
http://www.hobby-elec.org/e_ckt28.htm
steps up to about +30V from +5V power supply.
http://www.hobby-elec.org/e_ckt27.htm
This circuit will generate a smaller DC output voltage from a larger DC input voltage.It is quick and simple to make and by changing the value of the zener diode, the circuit can be universally adapted to provide other output voltages. The circuit and all
http://www.mitedu.freeserve.co.uk/Circuits/Power/dcdc_con.htm
o get a more precise output voltage, replace zener diode Z1 with 10V and R1 with a 1Kilo ohm potentiometer.
http://www.uoguelph.ca/~antoon/circ/car912.htm