What's the difference...

What's the difference between a H-bridge and a E.S.C. for controlling motors? I'm just not experienced with this sorta thing or terminology.
Thanks in advance,
BAM
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Tallguy wrote:

------------ All ESC means is just an electronic speed control, so what do you mean and what kind of motor?
An H-bridge is a means of reversing current direction through any motor coil using 4 switching elements in an H-configuration. It's used for DC motors and for bipolar stepper motors coils, but a unipolar stepper only requires a bank of four power transistors to ground.
Another way to do without an H-bridge is to use a dual power supply and use two switching elements top and bottom as a totem-pole switch of the two supplies into the motor coil with reference to a common ground into the other side of the motor coil.
Speed control is often done in single coil motors with PWM by modulating the pulse width of the power supply using another switching element and an oscillator to drive it. Speed in steppers is controlled by the step rate.
-Steve
--
-Steve Walz snipped-for-privacy@armory.com ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Tallguy wrote:

ESC's are not necessarily H-bridges, and vice versa. An H-bridge allows for reversing direction of the motor, and an ESC may or may not have this ability. More ESCs are designed for a particular control input signal (such as the 1.0-2.0 ms pulses used in R/C cars), whereas H-bridges need a PWM signal best adapted to the kind of motor you are using.
Not all ESCs use fully electronic speed control. Some are mechanical, and are meant to be controlled by a small R/C servo. The servo turns a pot, which alters the output of the ESC. And of course some ESCs are meant for manual control -- the speed control on a Dremel, for example.
-- Gordon Author: Constructing Robot Bases, Robot Builder's Sourcebook, Robot Builder's Bonanza
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Typically an ESC takes a signal that indicated direction and speed, and H-bridge is just a switching element.
--Chuck

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.