Nobody needs to bother about that, I´ve found, build and tested the next scheme, and it´s fully operational
I´ve used this circuit, one for each futaba s148 servo, I added some minors mods to have a bigger wide in the servo movemnt:
Simple servo controller
Description
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.
Partlist
1 x 555 timer IC
1 x BC547 transistor
1 x 10k Ohm potentiometer (mod with 50k)
2 x 10k Ohm resistors
2 x 100nF condensators
1 x 220k Ohm resistor
1 x 15k Ohm resistor (mod with another 15k resistor in parallel)
You can feed the circuit with 6v maximum.
I didn´t implement yet the swift circuit, by the moment is manually changed with the pot.
Hope it helps!