Using a beam sensor to activate a relay to reverse polarity on a linear actuator

Thread Starter

DonLitz

Joined Jun 9, 2017
7
This project is a race game for customer built Lego Cars.
I have a linear actuator that controls the start gate of the game. The kiddie places his car at the start line, hits the button and the actuator lowers the bar to release the car down the track. At the end of the track is a light beam sensor(s) that registers which lane is the winner and flashes an LED sign and audio cheering the winner. It is at this point that I need the start gate to move back into the start position and ready for the next race.

I would like to stay away from mechanical limit switches and or timers to perform this function, instead use the completion of the cycle to send a signal via relay to the actuator to go back up.

Any help would be greatly appreciated.
 

MaxHeadRoom

Joined Jul 18, 2013
18,863
Why not use a contact on the LED sign relay to trigger the actuator back to up position?
What is stopping the actuator when it lowers the bar at start right now?
Max..
 

Thread Starter

DonLitz

Joined Jun 9, 2017
7
Why not use a contact on the LED sign relay to trigger the actuator back to up position?
What is stopping the actuator when it lowers the bar at start right now?
Max..
I believe we were just going to allow it to go down to its built in limit. I like the idea of the contact on the relay. I am not an electrical engineer, but I did play one on tv. lol. is there anyway you can diagram this solution for me. Thanks
 

MaxHeadRoom

Joined Jul 18, 2013
18,863
So when the start button is pressed, does this pick up a relay for the actuator that stays on until the bottom actuator limit is seen?
IOW what is the present circuit for the start button?
Max,
 

Thread Starter

DonLitz

Joined Jun 9, 2017
7
Ok you're losing me.
In this order,
1. Actuator is in extended position placing gate in up position above track.
2. Kids place cars against gate and hit button on top of game to start race.
3. Cars speed down track past light beam sensor
4. Winners LED Banner flashes and sound card cheers.
5. System resets with Actuator back in extended position.

I need to figure out the entire circuit so I can procure hardware needed.
Hope this explains it better
Thanks
 

MaxHeadRoom

Joined Jul 18, 2013
18,863
Ok you're losing me.
In this order,
1. Actuator is in extended position placing gate in up position above track.
2. Kids place cars against gate and hit button on top of game to start race.
3. Cars speed down track past light beam sensor
4. Winners LED Banner flashes and sound card cheers.
5. System resets with Actuator back in extended position.

I need to figure out the entire circuit so I can procure hardware needed.
Hope this explains it better
Thanks
I assume this is your desired result, and if I read you correctly the description in the OP is purely the desired result, nothing of that is what you have now?
You say he places the car in the start position and hits the button , but this is not already in place I now gather?
IOW you want the complete circuit from scratch?
Max..
 

Thread Starter

DonLitz

Joined Jun 9, 2017
7
Yes, this is a project that we have done before and our "engineers" solution was very clumsy and has not stood up to time. We are trying to simplify the mechanical components, thus the actuator on the new race track.
 

MaxHeadRoom

Joined Jul 18, 2013
18,863
It would help to know if you intend working with other existing devices such as the light beam sensor, LED's etc, IOW what is there presently that needs integrating?
Max.
 

Thread Starter

DonLitz

Joined Jun 9, 2017
7
Ok Max, Thanks. I will create a diagram this weekend and post it. Appreciate your help.
 

MaxHeadRoom

Joined Jul 18, 2013
18,863
Also confirm that if the actuator does have internal limits, is it just two wire control, i.e. just reverse polarity on the pair to reverse?.
Max.
 

Bernard

Joined Aug 7, 2008
5,227
Most linear actuators ( ? ) reverse directions by reversing supply polarity. This simple circuit might work .
The beam break shown will not work as 555 reset needs a hard ground to reset & R2 would be in multi k range,
but when we know your beam break circuit we can adjust. 555 is used as a latch & relay driver. Initial condition
is U2 reset, gate up. SWitch is pressed setting U2, pin 3 high, relay, Ry, engaged, L-A lowers the gate. When a car breaks the lane beam, U2 is reset, L-A reverses, raising the gate.Gate Control #2 00000.jpg
Pin 6 should go to ground, pin 2-to R3 & SW, other end of R3 to +V.
 
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