Relay Logic

Beefy

Beefy

Worst gambler ever
So, today, as per usual, I'm thrown into a job with no information and a task to do.

I have a 4 pull, double throw relay that I need to integrate into a room with a duress button.

I have a Duress, a door strike with a trigger, a strobe and a mushroom button to activate the strike. So the way its supposed to work is that an officer sees trouble, and presses the duress button. Once he presses it, the strobe lights start to pulse and the mushroom button lights up so that when the officer leaves the room, he can push said button and lock the door. The door remains locked, via the strike, until the duress button is reset through a key.

Givens:

All wires are run back to the power supply and head end, meaning all relay wiring is done in the same place.

There's a relay in the door strike, called a trigger, that is powered by the mushroom button, which is tied into the normally open side of the 4 pull, double throw relay, of which the common is tied to power.

The duress button is a normally open that makes a circuit when pressed to activate the 4 pull relay.

The Strobe is on a normally open as well. Closes when the duress it pushed.

How do you wire this?
 
Sounds like you need some logic gates. It's hard to tell what exactly you're trying to do, but it sounds like simple NAND gate functioning (AND gate with logic inverter) if you're trying to get the strobe to go when both buttons are activated.
 
ib1yysguy said:
Sounds like you need some logic gates. It's hard to tell what exactly you're trying to do, but it sounds like simple NAND gate functioning (AND gate with logic inverter) if you're trying to get the strobe to go when both buttons are activated.
Click to expand...

relays are used as logic gates/

Beefy, you did not complete the function description.
do the lights keep flashing after door is locked?

What is the order to unlock the door?

darned incomplete requirements.
 
ib1yysguy said:
Sounds like you need some logic gates. It's hard to tell what exactly you're trying to do, but it sounds like simple NAND gate functioning (AND gate with logic inverter) if you're trying to get the strobe to go when both buttons are activated.
Click to expand...

relays are used as logic gates.

Two relays wired right will make and and/nand or or gate.
Inverters are simple too.

Beefy, you did not complete the function description.
do the lights keep flashing after door is locked?

What is the order to unlock the door?

darned incomplete requirements.
 
you have to take the belfour converter and hook it up to the restrictor module. then you wire a simple trip connection for the main duress switch. Also make sure to check the harness bolts and transistor frame. Shouldn't take very long.
 
uscitizen said:
relays are used as logic gates.

Two relays wired right will make and and/nand or or gate.
Inverters are simple too.

Beefy, you did not complete the function description.
do the lights keep flashing after door is locked?

What is the order to unlock the door?

darned incomplete requirements.
Click to expand...

Here's the chain of events.

In a small interview room, there is a duress button in case the interviewer feels threatened.

The button gets pushed, causing a piezo and a strobe light outside the door, as well as strobes throughout the office to turn on. It also powers up a led in a push button outside the door. When the interviewer exits the room and pushes that button, the door strike powers up and recedes, thus locking the door and the led in the push button turns off. The strobes and piezos continue to be active. Once the situation is rectified, a key is used to reset the duress button, at which point the entire system goes back to normal.

The duress button is simply a normally open latching contact.

It took me some time to figure this out, but it was good to finally get it. The key is that pushing the duress button is one half of the double throw relay firing, and the push button is what actually energizes it. Here's a little twist too. There are two rooms that were there to begin with with this system, but none of the wires were labeled and the relay was totally different, rendering it impossible to simply copy, and I had to add two new rooms. But each room had to fire the strobe only outside its door and ones on the ceiling throughout the office. I used two RIBs to do this.
 
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Grind said:
did you check the transistor frame?
Click to expand...

Actually, the reason I had to use RIBs was because diodes were unavailable. As for transistors, unnecessary, but rectifiers would have allowed me to go directly through the double throw relay as I was going from 24VAC to 12VDC. But I had neither diodes nor rectifiers. Transistors would have complicated the effort, if not entirely useless.
 
Beefy said:
Here's the chain of events.

In a small interview room, there is a duress button in case the interviewer feels threatened.

The button gets pushed, causing a piezo and a strobe light outside the door, as well as strobes throughout the office to turn on. It also powers up a led in a push button outside the door. When the interviewer exits the room and pushes that button, the door strike powers up and recedes, thus locking the door and the led in the push button turns off. The strobes and piezos continue to be active. Once the situation is rectified, a key is used to reset the duress button, at which point the entire system goes back to normal.

The duress button is simply a normally open latching contact.

It took me some time to figure this out, but it was good to finally get it. The key is that pushing the duress button is one half of the double throw relay firing, and the push button is what actually energizes it. Here's a little twist too. There are two rooms that were there to begin with with this system, but none of the wires were labeled and the relay was totally different, rendering it impossible to simply copy, and I had to add two new rooms. But each room had to fire the strobe only outside its door and ones on the ceiling throughout the office. I used two RIBs to do this.
Click to expand...


Don't you just love having to figure out how something works so you can either repair or expand it?
 
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