How to reverse a motor using a DPDT ... #2

Thread Starter

WaqarR

Joined May 5, 2021
5
Hi there!
I, as a part of a group, am working on a project to build a vehicle that reverses automatically after having a collision with wall.
One of the common solution is using a DPDT switch to reverse the polarity of a DC motor.
The problem that I am facing right now is what configuration of DPDT switch should I use and can you people think of any option other than a DPDT switch so that I have more than one solutions for this problem.
Thanks.
Kindly help me as it's urgent.

Mod: Link to other users Thread.E
https://forum.allaboutcircuits.com/...erse-polarity-of-dc-motor.168088/post-1489416
 
Last edited by a moderator:

Thread Starter

WaqarR

Joined May 5, 2021
5
This will do, but there's other questions. Current capability, voltage, time delay before you throw it in reverse..View attachment 237492
Actually I was thinking of a wiring a DPDT switch simply as you have represented in the above image.
As far as the time delay is concerned, I need to know whether there are push-button DPDT switches available so that when the vehicle strikes the wall, DPDT switch is pushed and the motor easily reverses?
 

Yaakov

Joined Jan 27, 2019
3,161
You need to consider the mechanics of actually operating the switch. If the vehicle strikes the wall at various angles will it work?

The usual method of doing this separates the collision sensor from the switching mechanism.
 

KeithWalker

Joined Jul 10, 2017
1,787
Switching the direction of rotation of a motor while it is running will cause a large surge of current through the switch contacts. Depending on the size of the motor, this could cause arcing that will damage the switch contacts. It is usual to power the motor down first and then reverse the direction after a short delay.
 

crutschow

Joined Mar 14, 2008
27,225
I suggest you consider a MOSFET H-Bridge to control the motor.
With that it's easy to momentarily stop the power to the motor before reversing.

What is the motor voltage and current?
 

Thread Starter

WaqarR

Joined May 5, 2021
5
I suggest you consider a MOSFET H-Bridge to control the motor.
With that it's easy to momentarily stop the power to the motor before reversing.

What is the motor voltage and current?
Actually it's my first engineering project. We have to make vehicle that operates by hand push and undergoes a straight line motion until it strikes a wall. Upon striking the wall, it should start moving in reverse direction.
The option I have in mind is an ON-ON push button type DPDT switch (mounted on the front side of vehicle). As soon as it collides with a wall, it reverses.
BUT
I want to use something different than DPDT switch as it's pretty conventional type of thing.
Now, I haven't decided the motor that we have to use.
Can you enlist some other options for me other than DPDT switch?
 

djsfantasi

Joined Apr 11, 2010
7,693
Actually it's my first engineering project. We have to make vehicle that operates by hand push and undergoes a straight line motion until it strikes a wall. Upon striking the wall, it should start moving in reverse direction.
The option I have in mind is an ON-ON push button type DPDT switch (mounted on the front side of vehicle). As soon as it collides with a wall, it reverses.
BUT
I want to use something different than DPDT switch as it's pretty conventional type of thing.
Now, I haven't decided the motor that we have to use.
Can you enlist some other options for me other than DPDT switch?
You mean like the solution you quoted?
 

MaxHeadRoom

Joined Jul 18, 2013
23,115
Presumably the motor has stopped revolving if it has hit a wall !!?
A collision SW and a pair of reversing relays would do it automatically
 

djsfantasi

Joined Apr 11, 2010
7,693
....

Can you answer the question please...it would be a great help
Now I’m necroposting. No, I couldnt answer the question in this thread. I would’ve answered the question if you created your own thread. The moderators even created your own thread for you and you ignored it.

When participating in a forum, there is a certain etiquette which is expected. You’ve continued to ignore etiquette and acted rudely. Some people have tried to help you regardless, but you would have possibly had your problem resolved if you weren’t so rude.
 

peterdeco

Joined Oct 8, 2019
357
What kind of vehicle are you making? A small model powered by a couple of AA batteries or a ride on vehicle with a gear motor and lead acid battery?
 

MaxHeadRoom

Joined Jul 18, 2013
23,115
If adding a automatic reverse via a collision switch, the automotive airbag collision method could be implemented.
This entails a inertia switch together with a collision contact point, switch.
In this case just the inertia SW could work.
.
 

LowQCab

Joined Nov 6, 2012
557
Here's a simple and yet sophisticated way you can do it ..................
Requires 6-Volts, ( 4-AA Cells ).
.
.
.
Low Power Motor Control FLAT .png
 
Last edited:

MrAl

Joined Jun 17, 2014
8,251
Yeah, DPDT is more of a conventional thing to use.
I want to know other solutions that I can avail.
I second the H bright nomination because with that you can do everything electronically with no switches. You can also use a relay with DPDT contacts but the H bridge will last longer.
 
Top