need help with dc motor controller using spst momenrary butt

[Sweetie Pinellas]

I am looking for a way to control two SPDT relays configured in a ground common configuration like in the link below, which will control the motor in three states. Normally it would use a SPTT toggle, but I want to have it operate on momentary spst push button. Push and hold it and motor turns clockwise, release and it stops, press again an hold it and motor turns counter-clockwise, and so on.

http://www.electro-tech-online.com/attachments/win-gif.91463/

 

[M Philbrook]

In article <ab44f71b-51b7-4863-86d2-3f83c9195f18@googlegroups.com>,
littleredvette79@gmail.com says...

I am looking for a way to control two SPDT relays configured in a ground common configuration like in the link below, which will control the motor in three states. Normally it would use a SPTT toggle, but I want to have it operate on momentary spst push button. Push and hold it and motor turns clockwise, release and it stops, press again an hold it and motor turns counter-clockwise, and so on.

http://www.electro-tech-online.com/attachments/win-gif.91463/

Look for flip-flop circuits.

Jamie

 

[Tim Wescott]

On Fri, 06 Nov 2015 12:13:37 -0800, Sweetie Pinellas wrote:

I am looking for a way to control two SPDT relays configured in a ground
common configuration like in the link below, which will control the
motor in three states. Normally it would use a SPTT toggle, but I want
to have it operate on momentary spst push button. Push and hold it and
motor turns clockwise, release and it stops, press again an hold it and
motor turns counter-clockwise, and so on.

http://www.electro-tech-online.com/attachments/win-gif.91463/

That circuit should work just fine with two pushbuttons -- unless I have
my head where the sun don't shine, if you should push both buttons the
motor will stop, just as if you leave both buttons off.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[M Philbrook]

In article <zIKdnVpyJvgcq6DLnZ2dnUVZ5vIAAAAA@giganews.com>,
seemywebsite@myfooter.really says...

On Fri, 06 Nov 2015 12:13:37 -0800, Sweetie Pinellas wrote:

I am looking for a way to control two SPDT relays configured in a ground
common configuration like in the link below, which will control the
motor in three states. Normally it would use a SPTT toggle, but I want
to have it operate on momentary spst push button. Push and hold it and
motor turns clockwise, release and it stops, press again an hold it and
motor turns counter-clockwise, and so on.

http://www.electro-tech-online.com/attachments/win-gif.91463/

That circuit should work just fine with two pushbuttons -- unless I have
my head where the sun don't shine, if you should push both buttons the
motor will stop, just as if you leave both buttons off.

The poster wants to flip flop it via a single button so each time the
button is pressed it just goes the other way, instead of using two
buttons

Flip-Flip with Clk.
Jamie

 

[Tim Wescott]

On Fri, 06 Nov 2015 18:37:45 -0500, M Philbrook wrote:

In article <zIKdnVpyJvgcq6DLnZ2dnUVZ5vIAAAAA@giganews.com>,
seemywebsite@myfooter.really says...

On Fri, 06 Nov 2015 12:13:37 -0800, Sweetie Pinellas wrote:

I am looking for a way to control two SPDT relays configured in a
ground common configuration like in the link below, which will
control the motor in three states. Normally it would use a SPTT
toggle, but I want to have it operate on momentary spst push button.
Push and hold it and motor turns clockwise, release and it stops,
press again an hold it and motor turns counter-clockwise, and so on.

http://www.electro-tech-online.com/attachments/win-gif.91463/

That circuit should work just fine with two pushbuttons -- unless I
have my head where the sun don't shine, if you should push both buttons
the motor will stop, just as if you leave both buttons off.

The poster wants to flip flop it via a single button so each time the
button is pressed it just goes the other way, instead of using two
buttons

Flip-Flip with Clk.
Jamie

I took "Operate on momentary spst push button" to be a non-native speaker
saying "one or many spst push button(s)".

If the OP cares, the OP will elucidate.

(So, how many relays does it take to make a toggle flip-flop? They
should be slow enough that switch bounce isn't an issue.)

--
www.wescottdesign.com

 

[Jasen Betts]

On 2015-11-06, Sweetie Pinellas <littleredvette79@gmail.com> wrote:

I am looking for a way to control two SPDT relays configured in a ground common configuration like in the link below, which will control the motor in three states. Normally it would use a SPTT toggle, but I want to have it operate on momentary spst push button. Push and hold it and motor turns clockwise, release and it stops, press again an hold it and motor turns counter-clockwise, and so on.

http://www.electro-tech-online.com/attachments/win-gif.91463/

sounds like you really want an alternating relay, the question now is
"buy" or "build".

--
\_(ツ)_

 

[Sweetie Pinellas]

sorta, I want two outputs that flip upon press, but also both be at ground when the button is released.

 

[Tim Wescott]

On Mon, 09 Nov 2015 05:56:30 -0800, Sweetie Pinellas wrote:

sorta, I want two outputs that flip upon press, but also both be at
ground when the button is released.

This would be really easy to do with logic. Are you bound and determined
to do it just with relays?

Actually, you could use an alternating relay to set direction, and
connect power to the motor relays when the button is actually pressed
(either through the button directly or through a relay). That should do
the trick.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[M Philbrook]

In article <79822028-ee83-46cf-bae2-22a54cf0e751@googlegroups.com>,
littleredvette79@gmail.com says...

sorta, I want two outputs that flip upon press, but also both be at ground when the button is released.

you can use two latching relays to drive the existing circuit you showed
before.

One relay loops around to the other using your momentary button
and the button needs to be SPDT so that when you press in it will
flip one relay, which in turn re-routes the path for the normally
closed contact when you release it. This will flip the other relay
so that the next time you press this button again, it has to first
pass through the second relay which has been switched from the last
operation and now activates opposite input to the first relay. When
the firt relay switches, it will also switch the second one, too and
so on.

During this time, you can use these signals to connect the two
relays you had before.

So in short, you have both a direct function and toggle function.

Back in the old days we had rachet relays, you press in and it simply
press the stroke arm forward and pushes on a claw to spin to the next
position. Releasing the stroke arm put it back in place for the next
move.

But those are not mechanically reliable, so the use of magnetic
latching relays work well in your application.

Jamie


Jamie

 

[whit3rd]

On Monday, November 9, 2015 at 5:56:36 AM UTC-8, Sweetie Pinellas wrote:
> sorta, I want two outputs that flip upon press, but also both be at ground when the button is released.

Buttons (momentary contact switches) have a lot of bounce. You can get
around that (use a SPDT button with 'break-before-make' character to
set/reset a relay) or rely on slow relays not being responsive to rapid fluctuations.

If the output toggles an odd number of times each button press, it'll LOOK like
it's working.

 

[Phil Allison]

Sweetie Pinellas wrote:

I am looking for a way to control two SPDT relays configured
in a ground common configuration like in the link below,
which will control the motor in three states. Normally it
would use a SPTT toggle, but I want to have it operate on
momentary spst push button. Push and hold it and motor turns
clockwise, release and it stops, press again an hold it and
motor turns counter-clockwise, and so on.

** DC motors do not take kindly to having the polarity reversed when spinning at high rpm and your proposed set up allows this to happen. Sudden reversals cause very large current surges that burns brushes and commutators. The damage is made worse if the motor has any kind of flywheel device attached- ie a prop or fan blade.

The motor should be made to stop before polarity reversal occurs, which might involve dynamic braking by applying a short or low resistance across the motor's terminals for a sufficient time.

..... Phil