how do I switch between accumulator and steam/coal based machine?

[TheRangerLOL]

Actually you don’t need the combinator for this to work. In that example the combinator is changing the “A” signal to “GREEN”. Simply eliminate the combinator and set the switch to operate when “A” < n (where n is your threshold).

Hmm, i guess so huh. I use the green signal for other things so I didn't even notice, haha.

[Theikkru]

[...]

Your main power grid should be whatever is connected to your factory. The boilers are going to be backup power from now on, right?

yess. so is this connection correct? (ill ask regarding the programming again once the connection already in place)
Screenshot (1292)_LI.jpg
[...]

There are 2 parts to this question, and unfortunately, the answer to both is no. The first part is how you make the connections for power and circuit logic. TheRangerLOL's post answers this part of the question.

The second part of the question is what you connect, and this needs to be split in 2 parts too:

First, you need to make sure the power connections are on the correct sides of the switch. In your screenshot, it looks like you have steam power and your base connected to one side of the switch, but solar power, your accumulators, and the circuit control are all not connected:

SSedit.png (1.87 MiB) Viewed 1247 times

In order to use steam as a backup, the power switch must be able to disconnect it from everything else, so steam power must be by itself on one side of the switch (with the control circuit, so the control circuit always has power), and everything else (base, solar, accumulators) needs to be on the other side:

bakdemoedit.png (371.54 KiB) Viewed 1247 times

After that, you have to figure out how to set up the control circuit. How you connect the circuit wires will depend on which logic circuit you use. There are basically 3 different kinds of logic most commonly used, and 2 have been presented in this thread. You need to choose one in order to figure out how to connect the circuit:

Type 1 logic is the simplest, because it doesn't need any combinators (though it may use 1). However, this logic only lets you set 1 threshold for when to turn the backup on and off, and will cause thrashing (fast, repeated switching) of the switch when it reaches that threshold. Type 1 logic is shown in these posts:

[...]

[...]

Type 2 logic requires 1 decider combinator and 1 arithmetic combinator, and allows you to set 2 power thresholds, 1 to turn on, and 1 to turn off, but it requires some math to calculate the thresholds, and can still cause thrashing of the switch under certain circumstances. Since it hasn't otherwise been described in this thread, I'll stop here:

t2demo.png (684.14 KiB) Viewed 1247 times

Type 3 logic is what I showed in my example post. This uses 3 decider combinators, and lets you set a low power threshold to turn the backup on, and a high power threshold to turn the backup off. Since the 3rd combinator helps the circuit remember its on/off state, the switch will not thrash:

bakstates.png (622.01 KiB) Viewed 1247 times

[MassiveDynamic]

Here is a simple no combinator setup using the power switch...

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Here is a simple no combinator setup using the offshore pump...

0eNqVk81ugzAMgF9l8hkqYEA3tMsOe4YdpgoFcFtL5EchqYaqvPsS0FC70f1cEE7sL/GHOUPTW1SahIHqDNRKMUD1doaBDoL1Yc2MCqECMsghAsF4iFjbWm57ZqQGFwGJDt+hSl30a6Xc74ej1Bgry9VFbeZ2EaAwZAjnK0zBWAvLG9QefgMRgZKDr5IinOlJcVZsigjG8JZuCn9ERxrbOaOMwPdotOzrBo/sRL4BX9aSbi2Z2u91C2tPejD1t35OpI31K8t95oz4OXQTBBoWbOZJiLhierJUwRO4OUHMlxkCMw0Pjd1lx+Sj3O2cCzq/WMiWUxUpjI2MD1pa0a1pyBcNidewAru/gv2MSNcR+epIrJCyT45b/wLSGmX/Z/vvNtMbNouFyrEjy2PsPU1TGyvZrwpJrp36mZ3Gu7r4jyLoWYO+B3jhqA8o2vHulRkMWk6ohwmXPaT5Nn/clts0KYvSuQ//IS2B

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Here is an SR latch version (emergency power turns on at A<40 and off at A>=90) using 3 combinators...

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