Factorio Forums

I've seen some nuclear throttles/controllers that are a bit complicated, or not as reliable as I would like. So, I'd like to take a stab at it:
The very basic gist: Request only as much fuel as you want per round of nuclear fueling in a requester chest. Enable the requester chest when steam is > a set point and enable the inserter when steam is < a set point. That's it.

With this setup, only the amount of fuel you requested is sent to the reactors, and the requester chest is not re-filled until the inserter is disabled.

Now some details of the basic throttle: Since requester chests cannot be enabled/disabled based on a signal condition, you have to use one decider combinator and a constant combinator. The constant combinator will have the number of uranium fuel cells you want. And the comparitor will send this signal to the requestor chest when steam is above the desired setpoint. In my setup, the chest is enabled when steam in a particular tank is >10k, and the inserter is enabled when steam is <9.9k (for a little hysteresis)

A little detail on my setup. The second requester chest is an "emergency backup" This one always requests four uranium fuel cells, and is always on (I used the constant combinator to set the requested value). If steam drops below a critical point (4k steam in my setup), the inserter is enabled, and fuel is sent as fast as the requester chest is re-filled until steam is good again.

In Practice This is my first play through, and I just recently got nuclear, so YMMV. I've used this controller on a 2x2 (4) nuclear reactor setup, and it seems to work fine. The biggest problem I've run into so far is that sometimes instead of the 4 fuel cells I requested, I get 5, which means one reactor runs twice as long. NBD really, but I would like it "PERFECT"

Let me know if you have any feedback!

You get more than you requested because of the robot worker cargo bonus.

Fiddling with the requester chest still seems overly complicated. The cleanest is to only remove the spent fuel cell when there isn't enough steam, read the hand contents of the output inserter, and only put in the new fuel cell when it's holding a spent one. You can override the inserter stack bonus to 1

I tried that, but when there isn't enough steam, the reactor is emptied of all spent cells and filled up with new ones. I want to be able to put 1 at a time. Once a single fuel cell is used up, the reactor is still hot enough to make steam for quite a while, so even 2 cells in the reactor at one time is a waste. So, ideally, insert one fuel cell, the reactor heats up, then wait for the reactor to get back down to 500c, then add another fuel cell, repeat. This was the best way I could find to do that.

Bacon117 wrote: ↑Tue Apr 02, 2019 6:46 pm I tried that, but when there isn't enough steam, the reactor is emptied of all spent cells and filled up with new ones. I want to be able to put 1 at a time.

Sounds like you didn't quite do what Serenity suggested, then, because that method does work (lots of people use this method, it's used in many of the reactor designs posted on the forum). You need two parts set up:

1) Set the inserter which removes empty cells from the reactor to only be enabled when steam is low. This way, when there's enough steam, the empty cell will just sit there inside the reactor's output slot.

2) Set the inserter which puts fresh cells into the reactor to only be enabled when the output inserter is holding a spent cell. This means that each time an empty cell is removed a new cell is inserted to replace it.

You then start the process up by manually putting one fresh cell into the reactor. Since the system can only insert a cell while one is being removed, the number of cells inside the reactor should never change: if you started with one cell in there, it will only ever put one cell in there.

If you still can't get it to work, post a blueprint of your setup and someone can tell you what's wrong

You then start the process up by manually putting one fresh cell into the reactor. Since the system can only insert a cell while one is being removed, the number of cells inside the reactor should never change: if you started with one cell in there, it will only ever put one cell in there.

That's where I went wrong. I didn't realize you had to "prime" this setup with only one cell. I enabled the throttle after I fired up the reactor for the first time, so the reactor was already full of cells, not one cell.

You can also automate the insertion of the first fuel cells. With a kind of monoflop that inserts one cell when you turn on a constant combinator. Basically create one pulse of a spent fuel cell signal. After that the inserter logic takes over. But it's somewhat complicated and needs a few combinators