OK, I am reasonably adept at soldering and such but have brain failure when it comes to understanding relays. Give me a the tools and I can swap out a clutch in a car in short order but this one has me stumped.

I have a car, 1994 Lotus Esprit S4, which I want to add remote trunk unlock to. The hatch (boot since an English car) has two large pins which are held in place when closed by spring loaded latches. The trunk is normally opened via a handle attached to a cable in the passenger compartment which unlatches both spring loaded latches. The hatch then pops up a bit by way of the struts attached to it.

I recently installed a remote lock/unlock unit for the doors which includes a button for trunk release. What I would like to do is have a linear actuator I will mount in the boot which would pull on the spring loaded latches thus releasing the boot lid.

The remote unit works such that when the trunk release button on the remote is pressed a pulse + signal is sent. Since the pulse is obviously not long enough to power the linear actuator, and does not provide enough voltage, I got a pair of Directed Electronics 528T relays. They are DPDT relays with an adjustable timer. The timer can be set to either A. specify how long power is supplied through the relay or B. to pause for the specified time before power is sent via the relay. I also have a linear actuator which has a built in limit switch/clutch so no worries on that front.

What I envisioned, but my limited brain cell activity to make happen, is for the following to occur:
1. Trunk button on remote is pressed, which sends pulse to 528T which then sends power to the linear actuator and retracts it. After say 10 seconds, the 528T timer (adjustable via an adjustable pot) stops sending power.For this step + would be to + and - to - on the linear actuator.

2. The same pulse upon pressing trunk button is also sent to the other 528T in step 1 is sent to the other 528T and after 15 seconds (so no overlap) it sends power so the linear actuator is extended again.

Of course for step 2 the +/- sent to the linear actuator must be reversed and once the actuator has been extended again the polarity must be such that the next time the trunk release button is pressed it will repeat step 1.

Make sense?

I have looked at using microswitches, limit switches, etc. but still not getting a picture of what needs to be done, etc. Schematics I might add are not my friend at all!

THANKS!!!

 

Many actuators have internal limit switches so that when extended. SW opens. On reversing V, act. closes until closed SW opens. One relay for timed power. one for direction.

 

Many actuators have internal limit switches so that when extended. SW opens. On reversing V, act. closes until closed SW opens. One relay for timed power. one for direction.

The linear actuator I have has built in limit switch so cannot be overdriven but still remains my quandry on how to wire up relays, etc.

 

I may have found a more "mechanical" solution (since my brain works better with mechanical things)

have a On/On switch which reversese polarity which is mounted so that when the liniear actuator is extended it sends + to + and - to - wires on the actuator. Then when the actuator is retracted it flips the switch to send + to - and - to + wires on the linear actuator.

The 528T is triggered by way of the pulse from the remote unit and provides power to the + via the switch. The actuator retracts and hits the switch and reverses the voltage triggering the second 528T which waits 10 seconds and then extends it again. On full extension it physically trips the switch and since the pulse from the first 528T has not been triggered it is ready for the next time the remote trunk release button is pressed.

Thoughts?

Here is a crude diagram:
A - Linear actuator
B - linear actuator rod which extends and retracts
C - Piece of metal which flips the On / On switch, side view.
D - On / On switch

Top image is actuator extended, lower retracted. They show how D manually flips the switch.

 

The bottom image C in the image posted prior is the attached piece which flips the switch as a side view.