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maxxsinner

All about contactors

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There are some who do use 12v contactors. Availability is a problem out here in the US. 24v are plentiful, thus a lot cheaper.
Sorry for the thread necromancy, but I thought the main reason for using 24V contactors is because of the current requirement of the ledwiz. Don't 12V coils require over 500 miliamps?

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To have the same power as 24V coils, wouldn't 12V contactors require double the current? Maybe ohm's law doesn't apply to pinsim force feedback.

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No, you're right about ohm's law, but I'm pretty sure mechanically they make some adjustments to keep the power requirements much the same. Dropping a 12v coil into a 24v contactor may have the effect that you describe.

FWIW, I just measured the draw on a Siemens 3RT1016-1BB41 and its pulling 154ma @ 24vdc

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Someone mentioned that the contactors could draw up to 3A for a brief moment when the coil activates, is this correct?

If they only draw 154mA then they should be pretty safe to connect directly to the ledwiz?

@ maxxsinner, thanks for your answer :)

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That is correct. Inrush current can be very high.

But as for connecting them straight to a ledwiz, it depends on what else is connected.

I have connected a few of mine straight to the ledwiz, but the contactors I use are electronic as well as a standard coil so it is build to reduce the inrush current as well as the holding current.

Ledwiz is design for controlling relays an LED's so I cannot recommend connecting them directly unless you know what chances you are taking.

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I'm sorry for the stupid questions, but if the contactors can draw up to 3A, if 5 contactors activate at the same time during multiball or some other event, they could draw up to 15A? What would happen to my poor 6.5A power supply?

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No such thing as a stupid question Blashyrk. Only seems that way at the start of a steep learning curve and we have ALL been there.

Contactors are a coil of wire that when electricity is supplied to each end, makes a magnetic 'pull' to pull the contacts together. This is called an inductive 'load' to the power supply, load meaning power consumer.

The thing about an inductive load is it resists the change in current flow; so a tap that doesn't like turning on... or off.

So when they turn on, they turn on with a split second spike of current flow. But the key part is the time - only a split second. So even if they are all on at the same time, the sum of your contactors would be less than an amp. And almost all power supplies handle inrush current without a problem. This is how Zebs booster boards work off a normal PC power supply. In regards to them not liking turning off, this is where the diode becomes important. The coil creates a spike a in voltage when it's turned off, so it needs the diode to help dissipate this voltage so it doesn't cause problems in the power supply or elsewhere.

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I have a couple of questions about contactors....

I'm definitely gonna be using Siemes contactors as they seem to be the best quality and don't lag. I've seen the 12V DC ones on Wolfsoft's site but they seem expensive compared to the 24V ones.

I understand I need a separate power supply to wire up the 24V ones. Would this work out much cheaper and is it any easier?

I also want to ensure that the contactors for the flippers do not activate while in Hyperpin menu mode. I understand there is a way to wire an octocoupler in with the contactor and LEDWiz to keep a circuit open to achieve this.

Does anyone have any wiring info on this please? Do I definitely need 2x octocouplers for both flippers in conjunction with the LEDWiz?

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The 12 volt ones are less common that the 24 so they are more expensive but I don't believe there is any difference in the sound. No real difference in wiring either other than instead of connecting 12 volts to the A1 of the contactor, you are wiring 24 volts. The LEDwiz controls the negative A2 side so it doesn't care if they are 12 or 24 or 48 Volt even.

If you want your contactors to not operate in Hyperpin menu mode, you just need to hook them up to a LEDwiz/booster board the normal way.

If you use the optocoupler setup, it will fire the contactors with the Hyperpin menu as the optocoupler wiring shifts control of the flipper contactors directly to the flipper buttons, rather than the LEDwiz.

Hope that helps.

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