dc speed control auto reverse

[ink]

Can anyone point right direction
I what to create a conveyer, when the conveyer reaches a certain point(limit switch) it will reverse direction and return home and stop.
I also what to control the speed. Already have a pwm work.

I am newbie but can read circuit.

 

[ink]

This will use a hobby dc motor not large scale.
i was hoping to use relays

 

[Misterbenn]

You wan to research 'H-bridge' or 'H-bridge motor control' and you'll find all the information you need.

Use relays if you want but I'm not sure why you would want to? I'd go solid state then you could just 'AND' the direction logic signal with your PWM signal to drive the motor.

 

[audioguru]

..... it will reverse direction and return home and stop.

A guy at the park had a toy quad-copter that flew pretty far away in the wind then he pushed a button on the transmitter and put it down.
Then the helicopter "reversed direction and returned home and stopped". Of course the helicopter carried a tiny video camera to record the pretty young ladies sunbathing far away.

 

[JimB]

Thank you for your insight into the expression:

reverse direction and return home and stop

Just so we are completely clear, was it you in the park watching the pretty ladies and playing with his joystick?
Enquiring minds need to know.

JimB

 

[audioguru]

Thank you for your insight into the expression:

Just so we are completely clear, was it you in the park watching the pretty ladies and playing with his joystick?
Enquiring minds need to know.

JimB

No, the pretty young ladies were fairly far away sunbathing in the park wearing only bits of green masking tape. They didn't see me coming.
No, they were not playing with my joystick, yet.

 

[alec_t]

I what to create a conveyer, when the conveyer reaches a certain point(limit switch) it will reverse direction and return home and stop.

When the limit switch operates you need to allow a delay period for the motor to stop before you reverse it.

 

[ink]

OK! I have the h bridge, but how would I stop motor and change direction automatically.

 

[KMoffett]

Using relays instead of an H-bridge....I did this once. You would have to add PWM to the motor supply for speed cotrol.

Ken

 

[4pyros]

My first thought was to use a LEGO controller. Look up LEGO Mindstorm.

 

[Misterbenn]

What H-bridge do you have?

To stop the motor you'll want all the H-bridge switches off, and to change direction you just need to change the switching pair.

try reading up on H-bridge motor control, there is plenty of resource on the web and it's really really simple! When you have an idea of how to control the motor we can help with the circuit design details.

 

[ink]

What would be the best option h bridge or relay.
from what I have most bislike pwm through relays.

 

[KMoffett]

What would be the best option h bridge or relay.
from what I have most bislike pwm through relays.

More details about the motor (voltage/current) and timing and frequency of operation would help.

Ken

 

[Misterbenn]

Yep we need more detail. What motor do you have? What h-bridge? How fast do you need the motor?

 

[KeepItSimpleStupid]

I need to ask if your having any trouble with braking and will that be a problem?

I did a hobby type of control once, but I had to brake the motor to stop it, otherwise it would coast out of position.

 

[ink]

Operates on 8 - 20 VDC Extremely high torque output -Rated at 6 oz. in. Stall torque at 12 VDC and 14 Amperes is over 30 oz. in. No load speed of 6600 RPM No load current @ 12 VDC -330 mA Torque output at 12 VDC and 2.5 Amperes is 6 oz. in. 5 pole armature

I need to use it about 100 time aday.
I am usure at what speed until I dod some test but that is more thab enough.

 

[KeepItSimpleStupid]

Does your H-bridge provide "brake" and do you need it?

 

[KMoffett]

Another issue...is this for personal use?...or an industrial function where safety is an issue?

Ken

 

[ink]

No brake it have 2 push button one forward one back I will post plan later today.

It will be used personal in a small business

 

[KeepItSimpleStupid]

The brake question:

When you stop the motor, does the motor coast and stop past where it's supposed to?

The reason is whether or not one has to employ dynamic braking? I think dynamic braking in this case is best done with the H-bridge. Not all H-Bridges have a "Brake" input.

e.g. the modes
coast
brake
fwd
rev
stop

or

coast
fwd
rev
stop