This cicuit allows you to test a servo. The angle of the servo can be set by means of the 10k potmeter. Perhaps you will not be able to reach all positions with this circuit. Playing with other resistors may help.
Part component;
1 555 timer IC
1 BC547 transistor
1 10k Ohm potentiometer
2 10k Ohm resistors
2 100nF condensators
1 220k Ohm resistor
1 15k Ohm resistor
1 BC547 transistor
1 10k Ohm potentiometer
2 10k Ohm resistors
2 100nF condensators
1 220k Ohm resistor
1 15k Ohm resistor