Differences

This shows you the differences between two versions of the page.

--- dig:servos [2013/03/04 09:39] – tobi
+++ dig:servos [2024/02/29 07:28] (current) – external edit 127.0.0.1
@@ Line 9: / Line 9: @@
 You cannot control the torque, rate, or anything else; as soon as the servo's electronics detects the pulse width (which can require several pulses) it tries to get the servo to the new position as quickly as possible.  You also cannot sense the servo's position, current or anything else; control is open-loop as far as the servo is concerned; all control is handled inside the servo.
 {{http://4.bp.blogspot.com/-RoXuyoxFQXI/UN953PdeCqI/AAAAAAAAAHs/MCyAovmWcwY/s1600/servo_pwm_pulses.gif|Servo PWM control}}
 The wiring of servo motors is also simple: 3 wires consisting of power, ground, and signal - see below. The input signal is a positive digital pulse of at least 2V. The power supply can range from 4V to 7V. Even higher voltages can be used but may burn out the servo if it stalls. The higher the voltage, the faster the servo.  Let's use the 5V VBUS USB power here, which is available on the AVR32 board. If we overload VBUS, we will cause a fault on the USB host adapter. We also need to watch out for the large fluctuations in VBUS which can affect the ADC reference voltage.
@@ Line 18: / Line 16: @@
 {{dig:servoconnections.png|Servo connections, from http://fatlion.com/sailplanes/servos.html}}
-To supply power to your servo from USB, use the part of the schematic below to build a semi-isolated servo power supply
+To supply power to your servo from USB, use the lower left part of the schematic below to build a semi-isolated servo power supply. Do you see why it helps isolate the sensitive supply voltage for the ADC that converts the microphone signal?
 {{:dig:micamp.png?800|Microphone preamp and servo power supply}}