I am working on a circut for a Lockup torque converter. Simply put its a 12vDC on selinoid. The problem is we need to be able to delay the on state for about 3-5 seconds after the 4th gear switch is made. I guess you could call it a simple delay on make relay, but I cannot seem to find a inexpensive solution. we also use a brake switch off relay in teh system, but that is easy to handle. I just need to be able to delay the on state for a few seconds every time the circut is opened. probably a simple issue, but I am no eltronics guy so I am stuck. Any body know a simple/ inexpensive way to handle this???



Charlie

 

Do you have a schematic? There are a few ways but we need to see what you're already doing to have an idea of what is available.

 

You need an on-delay timer; the contacts change state after it times out following the input signal [from the 4th gear switch]. For starters, check out Potter & Brumfield CB series CMOS timers. They have a 12 VDC model. Do a Google search for Potter & Brumfield. You'll also need an octal socket for this model.

 

I don't have any way to post a schematic here that I know of. Its a simple circut actualy 12v key on power to a NC relay (its opened by pushing the brake pedal) to a NO pressure switch (closed when the tranny reaches 4 th gear) to a selinoid which is already grounded. The problem is that when the selinoid activates the torque converter locks imediatly which since its at the same time as 4th coming on, requires a large fluid load on the hydralic circut.

I did think about the timer and socket, but the overall cost is a issue, WE do a hundred or so a year, and would like to be able to keep the cost in the 10-25$ bracket for the whole harness. I was wondering if a resitor or a capacitor in the circut would slow the apply? or if there is already a delay on make automotive relay. OR?? posibly a way to make a turn signal style relay stay latched?? The current draw is around .5 amps so its in the same range as a cpl turn signals (don't laugh I am a transmission guy not an eletronics one

 

So you need the relay to activate after the 5sec delay, then hold?
Or a signal comes and the relay holds for 5 sec?

 

Come on and hold. we use the brake light relay or the 4th gear pressure switch to unlock the circut when it need it. Either slowing down via brakes or loss of 4th gear opens the circut again.

 

Hmm, I still don´t understand what do you need from the circuit. Could you explain the function like "when a +signal comes, the relay does This, when the + signal gets lost the relay does This"?

 

when all the conditions are met, key on, pressure switch closed in 4th gear, and foot off the brake, 12 volts is run to the selinoid which activates the clutch, the goal is to delay the clutch on until the hydralic circut has stabilized, the current system turns it on as soon as the 4th gear switch is closed completeing the circut. The goal is to delay that about 3-5 seconds.

( if you have any suggestions on how to draw it on here let me know)

 

So without all the irrelevant things like 4th gear and such, you need a circuit that when 12V applied, turns a relay on after 3-5sec, and without 12V immediately turns relay off.
Is that correct?

 

Yes thats correct, it can be in front of or after the relay or part of it. Just some place in teh circut to provide a delay.