Yes thats right on the 24VAC secondary.
It sounds like the resistors, though they give me the right voltage limit my current.
I'm leaning toward the LM317 option.

You input voltage must be a little high, because 24VAC would only peak out at about 34V. But that might be 24VAC under some level of loading, too.

 

Here is the relay

 

Here is the relay schematic

With 1100Ω of resistance in the coil circuit, I'm guessing these relays aren't intended to be operated from 36VDC. What is the spec on the relay coils? Is there a reason you aren't using relays that can be powered directly from 12V or something similar?

 

as well as 5 SPST relays (directly off of the the 36-37V DC supply),.

24vdc or 48vdc coil!.
Max.

 

Here is the relay

So which one, exactly, are you using. What is the rated coil voltage?

 

With the coil resistances in the spec sheet and the 1100Ω he's got in series, I'm guessing that it is either 12VDC or 24VDC coil. With either he's close to the spec'ed current.

 

I'm using 12VDC coils, and I was running them off of the 7812 but the 7812 with a heat sink on it was getting pretty hot, so I just ran the 36VDC through some resistors and upsized them to dissipate the heat. Now the 12V of the 7812 can go just to the arduino.

 

I was working on the breadboard first with components I had to see what worked, and then checking with the multimeter, then I went over and started doing the schematic. Maybe that is a little backwards

 

I'm using 12VDC coils, and I was running them off of the 7812 but the 7812 with a heat sink on it was getting pretty hot, so I just ran the 36VDC through some resistors and upsized them to dissipate the heat. Now the 12V of the 7812 can go just to the arduino.

So is there any reason that you can't get a transformer with a 12VAC output (or something similar)? It just seems a shame to be dumping so much power as heat unless there's no reasonable alternative.

 

No reason at all. I'm just using what I have currently to breadboard and learn with. I figure I can always refine with better design and components, but it costs money to get them here first, so that is why I wanted to ask some questions of all you generous folks first

 

I was working on the breadboard first with components I had to see what worked, and then checking with the multimeter, then I went over and started doing the schematic. Maybe that is a little backwards

Yes and no. Until you get confident in your design skills it is not uncommon at all to build up and test circuits so that you can play around with them and see what does and doesn't work. There will always be pieces of projects that will push your skills and an hour or two spent up front in the lab can save a huge amount of grief and wasted effort at the end.

 

No reason at all. I'm just using what I have currently to breadboard and learn with. I figure I can always refine with better design and components, but it costs money to get them here first, so that is why I wanted to ask some questions of all you generous folks first

Sounds reasonable. Just gives us a better feel for the constraints you are working under. Where is "here"?

 

Ballard Washington, so not like Iceland or something.

 

So I think what I have might work, but it is certainly not optimized.

The right component seems to be a big part of efficient design.

 

If I have a 24V transformer that is 40VAC, does that mean I can get a max 1.66 amps?

 

Roughly, technically there is de-rating when smoothing capacitor are used.
Max.

 

If I have a 24V transformer that is 40VAC, does that mean I can get a max 1.66 amps?

Do you mean 40VA?

If so, then yes and no. That 40VA rating is for a linear load such that the voltage and current are both sinusoids. In your case, you have a very non-sinusoidal current that is characterized by very high pulses of current twice each cycle. So some derating is in order. MaxHeadRoom probably has a much better feel for how far you can push a typical transformer.

 

Roughly, technically there is de-rating when smoothing capacitor are used.
Max.

Are there any guidelines for determining the de-rating that is appropriate?

 

Do you mean 40VA?

If so, then yes and no. That 40VA rating is for a linear load such that the voltage and current are both sinusoids. In your case, you have a very non-sinusoidal current that is characterized by very high pulses of current twice each cycle. So some derating is in order. MaxHeadRoom probably has a much better feel for how far you can push a typical transformer.

yes I meant 40VA.

 

Here is a link for derating the transformer.
http://www.hammondmfg.com/pdf/5c007.pdf