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slow start n stop for gate opener

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ceolwynn

New Member
Hi fellow enthusiast ! :),

I am bulding a gate opener circuit to drive a 1/2 hp
24 v DC motor for our vehicle gate. the gate is 12 ft
long, 7 feet tall, wide and weighs about 200 pounds.
The sudden start and stop from my controller is really
stressing out the mechanical parts. another challenge
is that it is not quite on level ground, there is a slight
downslope on the closing run so I need at least a 3
second decel from 100% to 30% to handle the down
slope additional momentum on the "close" run.

so I need to add to this, a circuit that can take
about 2 seconds to go from a .5v output, to a 10 v
output, run until a limit switch either closes or opens,
and then ramp down from the 10 v to .5 volts in
about 3 seconds.

The motor controller I am using is a Dart 65E40
and it has 2 methods of control, 100% on / 0% off,
or a 0 -to- 10 volt speed control input. at zero
volts it runs the motor at 30% and at 10volts 100%.

The annoying part is that the designers included in
this controller a 0 -to- 10 second adjustable
acceleration adjustment, but only a fixed .5 second
deceleration mode ??? rats... I tried it and it is too
short for decel to be useful on the close mode especially !

I have been studying and collecting the many
versions of the Slow on / Slow off light dimmer
controller, to see if I could use it as a staring point
but I don't have the level of design experience to
modify the existing slow on / slow off circuits to
do the ramp up / run / ramp down pattern I need.

Since I am using dual 12v bateries to run it all
I also have the option to cut-out one of the batteries
as a slow down method as well when the motor gets
shut down to only 12 volts. but even on 12v it still
needs the soft start n stop.

who might know of any basic circuits that could
do this ramp up / run / ramp down pattern ?

or maybe a few separate circuits I could run in
series ?

thanks ... // Tom \\ Dallas Texas
 

ceolwynn

New Member
slow start n stop for gate opener - PS: -

I forgot to mention where I am at now...

I have been trying to use a quad 555 timer
with a 2 second one, and the end a 3 second one,
and using two of the quad timers as a missing pulse
detector to pick up on a closing / opening limit
switch to trigger the final 3 second ramp down
timer.

on the outputs of the ramp timers I am trying to
use a basic RC pair that can take the 2 and 3
second times to slowly saturate . it is not working
out so good :p

NOTE: the motor controller also has Pots for
max speed, and max amps. I have also been
experimenting with setting those Pots to Highest
settings and bridging them with lower resistance
fixed resistors which connect via limit switches I
have been double sided taping onto the limit switch
track in the drive train frame.

but this still has a jerky effect on the motor
speed and the mechanics of the drive chain .

I feel that the smoothest operation is going to
come from using the 0 -to- 10 volt speed input
build into the controller.

I am also working on a reversing circuit that
will be triggered by a garage door impact detection
strip I have attached to the leading edge of the
gate, so if it bumps anything, the gate will stop
in any position, and then restart the opposite way
until fully open again.

// Tom \\
 

dougy83

Well-Known Member
Hi Tom.

Please excuse my ignorance, but how is the driver board told to start/stop/reverse/etc.? I had a quick look at a Dart 65E series brochure but could only see an on/off switch and an inhibit switch as a means to control the driver. Any chance you could draw up a quick sketch of how it's wired up?
 

user_88

Member
... Seems like your RC pair suggestion ought to be able to assist with the 0-10 volt interface to the motor controller. ...It may not give you a precisely linear increasing ramp, but it should moderate the increasing portion of the initial gate closure.
What does your RC circuit look like .... what values are you using?

For the decel portion of the gate closure, would you be able to activate or enable a second RC circuit, as it is applied to the 0-10 volt gate signal?

You might take a look at the LT Spice circuit simulator program. This could help in determining RC values for your circuit modifications. ... Also, it is easier to see what you are doing if there is a diagram available.
 

jpanhalt

Well-Known Member
Most Helpful Member
Have you considered a dedicated motor controller? I have used the TPIC2101, and such functions are effectively built in and controlled with resistors. I suspect there are newer chips available.

As for stopping under load, I had a 50X18 ft steel bi-fold door that opened up and down. I addressed the braking mechanically by using a worm gear to belt drive for my speed reduction. The worm gear provides substantial and relatively soft self-braking.

If you want instant reversal at intermediate positions (i.e., for safety) but slow starts and stops at the end positions, a microcontroller might end up to be the easiest solution.

John
 

ceolwynn

New Member
Hi Tom.

Please excuse my ignorance, but how is the driver board told to start/stop/reverse/etc.? I had a quick look at a Dart 65E series brochure but could only see an on/off switch and an inhibit switch as a means to control the driver. Any chance you could draw up a quick sketch of how it's wired up?
================================================
// Tom \\
since I am not using the 65E40's reversing function, the 65E40
driver Board has no idea of direction, all it knows is 2 second start,
run, 3 second decel, stop ... the limit switches I added to the
original frame will signal the decel-begin point. every single start up
regardless of gate position should have the 2 second soft-start.

sketch ? sure :) I will hook it up like the Manual diagram,
here is the online manual showing the standard Motor reversal
hookup via a 3PDT Relay... I got this 30 amp one from Grainger
Relay,Power - Relays - Relays - Electrical : Grainger Industrial Supply ...
I got a Couple of DPDT ones too for battery isolators.

The reversal relays will be set via Limit Switches on the actual
mechanical worm gear attached to the chain drive axle at the extreme
limits to the gate movement, I am basically using the original ones
still in the commercial frame.. the orginal one that the lightning fried.
Allomatic

but I removed the still-working 120v AC motor and stashed it
for some later project, and installed this 24v DC one a couple
weeks ago ... Motor,1/2 HP,24 Vdc - DC Permanent Magnet Motors - General Purpose Motors - Motors : Grainger Industrial Supply

I measured and rated everything before buying this one. it is
the same hp, and within 200 RPMs of the original AC motor and only
2 inches longer. it fit in the mount fine and the pulleys and belts are
all ready to go. I will have to install a bulge on the weather cover.

I will activate the gate and garage door with these radio sets.
I LOVE LOVE These things !!!
Oatley Electronics
Oatley Electronics
The range is incredible ! anyways, they out put a +5v signal
that is momentary while transmitter button is pressed. this 5v signal
will go through 6 or 7 Diodes to make it 1.2 v, then into the LED of
this Optical coupler -- QUAD CHANNEL PC817XJ000F -- which can
easily handle the 24v DC on its transistor side to drive my relay coils.
( Rated up to 80v ) then the relays latch of course.

The reversing relay coil will be latched on, and de-latched by the
opening of the original limit switch on the gate system frame. at which
point the reversing relay sets up for the opposite direction.

I have not started on the batteries monitoring circuits yet. but
I know what I want done. probably will take a MCU for that.

When the gate radio receiver ( or garage door ) gets a signal,
the battery charger disconnects 1st, then the gate motor driver
gets signaled and is free to power up. when the gate cycle finishes,
the battery charger relay times out after about 10 minutes and
then re-connects the charger to the batteries.
The charger is this dual-bank version....
Battery Tender 2 Bank Battery Charger Model 022-0165-DL-WH
it is supposed to NOT cause trickle charger sulfation damage.
but I want a monitoring circuit watching the two batteries so that
every 10 days I can have the battery charger stay disconnected till
the batteries reach about 80 %, then reconnect and function as
before until another 10 days passes.

I am also collecting circuits that will detect when the motor has
stopped before allowing "reverse-direction" ... if the system reverses
while the 24v DC motor is still moving, the 65E40 board could get fried. !
so far I like this one as a starting point idea :)...
Welcome to Jameco Electronics! Great Products, Low Prices.

but the main thing I need now, is the circuit that will let me set
a 2 second analog voltage ramp up from .5v -to- 10 volts, run,
then activate a 3 seconds ramp back down to .5 v upon the
closing / opening of a limit switch... I would like this to be
adjustable to within a 2 - 5 second range on each side.

I have found many user adjustable ramp up / down circuits, and
this one so far is perfect in programming design and output pattern.
Welcome to Jameco Electronics! Great Products, Low Prices.

Here is the manula where it shows the adjustable ramp up / down
pattern of output ... ( Page 14 )
https://www.electro-tech-online.com/custompdfs/2009/10/manual_k8029.pdf

but I am unable to figure out how to modify it to be powered with
24v DC ??? and so far even though I have got two emails about
this circuit from the design company, they have not told me yet if
it's output is analog voltage shift, or Pulse Width Modulation ?

but even if it is pwm, I can use a simple "Frequency -to- voltage"
converter to fix that :)... and there are a few OpAmp setups
I have found to change voltage range "A" into voltage range "B" :p

if someone could help me figure out how to get that soft on /off
dimmer kit to be powered with 24v DC I would have that challenge
about 80% done !!!

I have had a good time researching and learning for this project !
and really hope to learn and teach what I can from here ! :)

// Tom \\
 

ceolwynn

New Member
Existing Kit for Soft Start / Stop ...

...
What does your RC circuit look like .... what values are you using?
===============================================
// Tom \\
I will not be sure until I have the rest assembled and hook up my
resistor bank box to it. but I am not putting much time into that
since I am hopefully trying to convert the Velleman K8029 from
120v AC to a DC Supply ??? ...




For the decel portion of the gate closure, would you be able to activate
or enable a second RC circuit, as it is applied to the 0-10 volt gate signal?
===============================================
// Tom \\
I hope to find a way to convert this kit to use in my project.
Velleman Inc.

it is awesome easy to program the ramp up and down settings as
you can read in the little manual ! ( pg 11 )
https://www.electro-tech-online.com/custompdfs/2009/10/manual_k8029-1.pdf


1st hurdle is to figure out where to inject a DC supple between the
existing 120v AC section and the working parts of the circuit.

since it is a micro processor circuit, i am sure it is not a 120v
AC powered MPU ?? :p ... weird ... so somewhere at some
point, the circuit is 5v I suspect. so, here is what I am already
doing...

The 24v DC supply from my batteries is turned into 5v DC by
these very convenient DC Supplies... I always have a few on
hand, Switching voltage regulators - 7805 replacements
so, from my 5 volt supply, where do I power the K8029
Velleman kit with DC, ??? and what parts then can I toss out ?

I have one but I may have damaged the MPU already trying to
extract the AC Supply parts / Insert the DC parts... I ordered 2
more that I should have by friday hopefully :) the next one I
will get DC / AC Voltage Meter readings at every single juction first.

attached is the circuit I need to power with a DC supply... also, the
primary circuit output, at R7 feeding a Triac, I want to translate
into a .5 -to- 10v analog output signal. I don't need the triac :)

// Tom \\
 

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dougy83

Well-Known Member
Ok, that manual's a bit more informative than the brochure I saw. I don't have time to work it out at the moment, but you can probably connect a resistor from U3-2 pin 5 to 12V, which will give you acceleration and deceleration control. I'd try a value between 270k and 470k for starters.
 

dougy83

Well-Known Member
Better yet, replace R16 & R17 with 220k. Use a 10k pullup from U3-2 pin 5 to 12V. That should give you roughly equal acc / deacc. rates adjustable up to ~6seconds.
 

dougy83

Well-Known Member
Might not work if you set the speed pot too low (i.e. <6V), but otherwise should be ok..
 
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