--- In Electronics_101@..., "wombat_eagle" <wombatt@...>
wrote:
--- In Electronics_101@..., John Popelish <jpopelish@>
wrote
Probably 5 or 6 volt as they're using motors from old tape or disc
drives, I'd guess 1 amp or less and should be reversable but that can
be handled by a DPDT switch.
What I'd like to find right now is a simple PWM circuit using either
gates or op-amps, any suggestions as to where to look would be
appreciated. I'm working with a group of high school engineering
students, we're building a robot and need soime motor controls.
I just uploaded to the files section (Popelish folder) a simple
schematic for a circuit that uses mostly dirt common parts and
converts a DC control voltage to PWM output for a small DC motor. The
only unusual part is the output switching transistor, which is a high
current, high gain device in a small package. It runs about $9 for 10
pieces from Digikey.
Here is the data sheet:
The LM393 is a dual comparator with an open collector output.
You probably want the P or N suffis part, for a through hole (or
socketable) part.
The B section is a triangle wave generator and the A section compares
this to the DC control voltage, and turns the PWM on any time the
control voltage is more positive than the triangle.
