Servo motor control

• Circuit measures currents in dc servo motor - This simple circuit design lets you measure all components of a current flowing in a dc servo motor. The rectified output of the circuit uses ground as a reference, so you can measure the output by using a single-ended A/D converter.   
• Controlling RC servos   
• Hacking a Servo - what is inside typical RC servo and how to modify it   
• motiontoolbox.com - engineering focused website ith a searchable growing database of servomotors, drives and, motion controllers and precision gearheads, site has also article archive   
• Pulse Width Position Servo   
• Servo Control Facts - A handbook explaining the basics of monition. This handbook is in pdf format.   
• Servo Control of a DC Brush Motor - This application note examines the use of the PIC17C42 as a DC brush motor servo controller. The servo system discussed in this application note uses a PIC17C42 microcontroller, a programmable logic device (PLD), and a single-chip H-bridge driver. Such a system might be used as a positioning controller in a printer, plotter, or scanner.   

RC servo control circuits

• About.com Guide to Radio Controlled Vehicles   
• AVR microcontroller makes improved motor controller - This circuit provides a novel method of reading the pulse train using an   
• Centronics port generates narrow pulse widths - Variable-pulse-width signals are useful in control circuitry for positioning and holding purposes in robotics and power electronics. Frequently, the need arises for pulses with width less than 1 msec. Delays less than 1 msec are usually not available in most programming languages, so generating such pulses can be a problem. To generate a fractional-millisecond delay you can use a PC's 8254 16-bit timer (Counter 2), which normally controls the PC's speaker. The desired pulse is available at the PC's Centronics port through a buffer stage, which protects the port from overload damage.   
• Controlling Hobby Servos with 0-10 volts - Generally hobby servo's require a pulse having a variable width from 1 to 2 milli seconds, with 1.5mSec as the center position. This schematic is a simple 0-10 volt voltage to pulse width circuit. It doesn't get more basic than this, all components are fairly common. The main draw back is that this circuit is not real linear.   
• Futaba compatible servo tester - This is a simple RC servo motor tester/controller based on CD4001. A potentiometer controls the servo position.   
• Futuba Servo Data - information on tens of RC servo models   
• Hacking A Servo For Continuous Rotation   
• Hacking a Servo - This document describes how servo motors work and hot to convert a servo motor to a really nice compact gearhead motor with built in electronics.   
• How-to: Forward / Reverse Micro ESC   
• How RC Works - This document gives view to a typical RC signal transmission.   
• How Radio Controlled Toys Work   
• KIT102 Servo-Motor Driver - All the work controlling the servos is done in the preprogrammed PIC micro-controller (uC). As such the kit provides a text-book example of how a uC can replace a handfull of IC.s & other glue chips. Everything is done in software (some source code included to text).   
• Mounting Secure Servos - All hobby servos have the standard mounting holes, but there are times when the standard mounting holes do not fit the way you want to mount them. It seems, especially when it comes to robotic applications. This document proposes an alternate method of mounting servos. This document deals with mounting one servo to the shaft of another, although the method can be adopted for many other mounting requirements. In a nutshell we will (1) dismantle the servo, (2) drill a hole to place a screw from the inside of the servo, (3) drill a hole to allow the screwdriver access to the screw's head, (3) mount the servo to the desired mount while dismantled, and finally (4) reassemble the servo while it is mounted.   
• Parallel Port Interface to Servos - includes example program for PC written in BASIC     
• Parallel Port Servo Controller - gives you 256 different positions over the full range of the servo   
• PIC Based Serial Port Servo Controller - This Servo Controller uses a PIC16F84 microcontroller from Microchip to drive servo motors and digital outputs. It receives commands from a host computer via a standard RS232 serial interface. This circuit supports 4 servo motors and 4 digital outputs. Circuit can be modified for 8 servo motors.   
• PIC R/C Servo Control Code   
• RC Electronics Projects - lots of projects published in the UK magazine Radio Control Models and Electronics   
• R/C Web Directory   
• Servo Motor H-Bridge replacement - TTL driven from the TTL DIR level, based on 7404 ICs and will provide about 150ma of current   
• Six transistor H-Bridge PCB replacement for tower hobbies servo - How many times have you looked at that dead servo on the corner of your bench and wished that you did not have to buy another? This is a replacement driver board for a standard Tower Hobbies servo using the 6 transistor H-Bridge. Replaces the existing PCB inside the Tower Hobbies servo as sold by Solarbotics with the standard positive input transistor H-Bridge circuit.   
• Servo Chart - Here's a partial list of the major brands of servos and comparative data.   
• Servo Connector Wiring & Command Chart - wirings and signal used with RC servo motors   
• Servo pulse to PWM converter - Radio-controlled cars, boats, airplanes, etc use servos to control steering and other functions. The interface is well defined and the servos are quite affordable, so they are also used for robotics and other clever purposes. The circuit presented on this page attemps to be an interface to convert pulses such as provided by R/C receiver to a dual PWM(Pulse Width Modulation) signal required by an   
• Servos 101 - basics of RC servo motor operation described   
• Servo Lead Pinouts   
• Servo-Motor 101 - introduction to RC servo technology and some ideas for servo modifications   
• Servo Motor Driver - based on PIC16C71, kit from   
• Servos Wiring Diagram - This document give you introduction to RC servos (both analogue and digital). It also describes the pinouts of most common servo motor models.   
• Simple 555 based servon control circuit   
• Simple RC Switch - Simple switch which may be used instead of servo and mechanical micro- switch. Works on all Futaba compatible RC systems. This switch can be used in proportional or 2/3- way channel. Connect IN to receiver signal output and a relay etc to OUT to suit your needs.   
• The RC Transmission! - text explains what kind of signals are sent from the TX to the RX of an "FM" radio control set, how they are decoded, and ideas about producing it yourself   
• Using Servomotors with the PIC Microcontroller   
• Variable Speed Control Modification to the Futaba S3003 RC Servo   
• Various Information on Servos - RC servo related information and circuits   
• Various Information on Servos - RC servo motor cross reference and example circuits   
• Hitec Servos Data   
• Some Observed Data about Servos - This article has general comments on SC servos on the market, comments are based on testing 50 servos from several manufacturers   

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