Help with control by wire - circuit needed

[TrailRat]

I am after a PWM circuit that can be used to help me build a two
wheeled carry cart. I will want to be able to control the the speed of
two motors so I can intiate turns. Skid steer is the term I think.
Forward and reverse also required. Control of cart will be done from a
handheld unit connected by umbilical. Unsure as to put circuits with
the switches in the handheld or in the cart with the batteries and
motors. Any advice or help would be useful. Please don't suggest
looking for help in the library or search engines as their seem to be
so many variations of the PWM circuits and I have no idea which would
suit my task.

Many Thank

Gadget

 

[Chris S.]

TrailRat wrote:

I am after a PWM circuit that can be used to help me build a two
wheeled carry cart. I will want to be able to control the the speed of
two motors so I can intiate turns. Skid steer is the term I think.
Forward and reverse also required. Control of cart will be done from a
handheld unit connected by umbilical. Unsure as to put circuits with
the switches in the handheld or in the cart with the batteries and
motors. Any advice or help would be useful. Please don't suggest
looking for help in the library or search engines as their seem to be
so many variations of the PWM circuits and I have no idea which would
suit my task.

Many Thank

Gadget

Any of those circuits you found would most likely fit your task. It's
really the circuit that is fed the PWM signal that is dependent on your
application. Depending on the size of your motors, you'll need to
amplify the power of the PWM signal to drive the motors, such as with an
H-bridge.

However, another aspect of the overall controller to consider is
complexity. You can make a PWM circuit using something as simple as some
555 timers, or as complicated as a microcontroller. Personally, I find
the microcontroller route far simpler in the end, as it allows you to
easily incorporate "intelligent" features into your design by simply
reprogramming the controller. I prefer Atmel's AVR micros and the SP12
in-circuit programmer.

 

[John Jardine]

TrailRat <Gadgetfreak_2000@hotmail.com> wrote in message
news:90322cbd.0408060708.3a9adb42@posting.google.com...

I am after a PWM circuit that can be used to help me build a two
wheeled carry cart. I will want to be able to control the the speed of
two motors so I can intiate turns. Skid steer is the term I think.
Forward and reverse also required. Control of cart will be done from a
handheld unit connected by umbilical. Unsure as to put circuits with
the switches in the handheld or in the cart with the batteries and
motors. Any advice or help would be useful. Please don't suggest
looking for help in the library or search engines as their seem to be
so many variations of the PWM circuits and I have no idea which would
suit my task.

Many Thank

Gadget

Most of the simple PWM circuits you come across will be OK. Even something
like a 555 feeding a TIP Darlington is quite capable of running a big
golf-cart motor, so a couple of these types of PWM could do the job.
Electronic reversing would need an H bridge. Much easier though with relays.
regards
john

 

[hamilton]

TrailRat wrote:

I am after a PWM circuit that can be used to help me build a two
wheeled carry cart. I will want to be able to control the the speed of

Do you mean a two wheeled balancing robot ??

http://www.geology.smu.edu/~dpa-www/robo/nbot/

Or do you mean a two motor tracked robot

http://www.srl.org/shows/ntt/track.html

or do you mean a three wheeled robot, where there is an idler wheel ?