relay order

I have three relays that I need to activate in a certain order. Should these be wired in series? Parallel? Some combination thereof? I need to make sure that Relay 1 switches before Relay 2, and Relay 2 before Relay 3.

What are you using to trip the relays? What exactly are you trying to do?

i am an idiot wrote:

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What are you using to trip the relays? What exactly are you trying to do?

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Building a type of remote starter. Relay 1 activates bypass, Relay 2 starts ignition and Relay 3 cranks starter. I have a momentary pulse of 5v that is put through a reed relay to have 1 12v+ available to drive the 3 relays.

Edit: Relay 1 and 2 will be double coil latching relays, relay 3 is SPST

I have never worked with a double coil latching relay before, I have a few questions. How many connections are there on the relay? How many for the coils and how many for the actual switching mechanism? Can you post a link to the relays? I can draw you a diagram that actually looks like the relay.   

Will the cycle be Bypass, ignition, start, and then off? Is there a negative pulse for off or will it too be a positive?

Are these latching relays available in DPDT format?

i am an idiot wrote:

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I have never worked with a double coil latching relay before, I have a few questions. How many connections are there on the relay? How many for the coils and how many for the actual switching mechanism? Can you post a link to the relays? I can draw you a diagram that actually looks like the relay.   

Will the cycle be Bypass, ignition, start, and then off? Is there a negative pulse for off or will it too be a positive?

Are these latching relays available in DPDT format?

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I'm having trouble sourcing bistable relays for a price I'm willing to pay, so I'm just going to use SPDT set up to latch. I spent a few minutes in paint and have a diagram:



I need R1 to activate first, bypass has to be active for the other two to work.

R2 has to activate second, accessories needs to be hot to crank.

R3 is last, and cranks starter.

The 12v pulsed is going to be hot for 2 seconds (when I start the car). This will activate R1, R2 and crank the engine for 2 seconds.

It's easy for me to extend the duration if that would help?

Link is broken somehow. Direct link:

https://img371.imageshack.us/img371/7987/relaycircuitwp5.png

I think we can do this with a lot less relays, if of course this situation will work for you. It is very easy to delay the triggering of a relay. How about this, touch the switch = bypass. Touch and hold 1 second = bypass then ignition. Touch the switch 2 seconds = bypass, Ign and then start.   If this will work let me know. If ignition is already on, you will still have to hold for 2 seconds to start. All off will be a but of a task, but I am going to sleep on it.

Hyperlink to your pic

https://www.avr-asm-tutorial.net/avr_en/index.html

Your best bet here would be to use a programmable microcontroller.  It will be more initial work, but a much cleaner system and much more reliable over the life of the car.  It will also be stable in extreme temps (RC circuits won't be).  This type of microcontroller is what the remote start manufacturers use for their timing and control.  Using a programmable logic controller will also give you the ability to incorporate much better features in to the entire system (like push to stop, automatic cranking, etc.) 

If you are going for a completely keyless operation system I would strongly recomend not using 20 relays to control the thing - it would be a nightmare to troubleshoot in 12 months when a relay fails or something else happens.

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Kevin Pierson

The activation circuit already uses two STAMP2's, I'll see about incorporating another. I hate coding assembly heh. Worst case I'll just use two switches to activate the bypass.

If you are already using two processors it should be much, much, much easier to incorporate the logic in a processor compared to trying to do it with relays.  Microprocessors were invented to replace relay logic - if you have the ability then use it - it will be a MUCH better system when done.

Simply coding up a one input and three output program should only take a few mintues, compared to hours of figiting with different resistor/capacitor values and relay configurations.  Plus, your overall cost will be significantly lower, and you won't have to worry about finding latching relays - you can latch in the logic.

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Kevin Pierson