13 replies to this topic

[dondi]

I noticed some PinCab build communities using 24V AC contactors in lieu of 24V DC contactors (mainly the Pincab Passion guys and the Monte ton Cab FB Group guys). These contactors have a deeper/stronger "thump" vs. the more-common Siemens 24VDC versions. I am considering using six of these for the bumpers + two 12V 60N Solenoids for slingshots and two Siemens 24VDCs for the flips.

Here is the 24 AC Contactor

 

In reading the PinScape Build Guide, I want to ensure I am thinking about this correctly.
I am assuming I need a 5V Relay to power the six AC Contactors? (I will be using MikePinball's PinScape AIO as the controller)
Something like this for the relay to the six AC Contactors, or will the PinScape AIO be able to handle feeding 24VDC to these Contactors? When there is no SainSmart involved, a MOSFET4 card is used between the contactors and a KL card.

 

Here is the snippet from MJR's Build Guide I am referencing. 

 

I believe the guys using these AC contactors already have a SainSmart (no AC relay needed), so maybe someone can guide me in the right direction and let me know if I would need the six relays for six 24VAC Contactors to work with a PinScape AIO controller.
 

Edited by dondi, 06 January 2020 - 11:04 AM.

[MikePinball]

No Pinscape cannot handle driving AC Loads. You will need either AC capable relays or SSRs that also support AC. Note that the AC relay board you show is NOT the same as the relay board other people use for their DC toys.

 

I think you are solving the problem the wrong way. First of all you don't know how good or bad it is until you try it out. There are several other "fixes" to getting a bigger thump:

1. The contractor washer trick where you put a small washer inside to get a more metallic thump (I'm doing this)
2. Use a different kind of DC contractor. Other people use starter solenoids for cars or refrigerators
3. Use solenoids or even Pinball solenoids.

[dondi]

Had a conversation with Olivier Servais (one of the "Pro" Pincab Builders on PinCab Passion & Monte ton Cab who is using 24V AC Contactors). He says they are using the MOSFET4 boards between the FreeScale and the AC contactors, feeding 24V DC in the usual way.

 

Here is a snippet of the schematic they follow, but instead of 24V DC Contactors, many of them are using 24V AC Contactors.

 

Olivier did say, 

yes I supply 24VDC and no problem unless the coil is supplied for a very long time, there is a risk of overheating, it never happened.

 

Aren't there MOSFETs on PinScape AIO Power Outputs (4A max I believe)? Wouldn't this setup be the same as what these French guys are doing? Basically there is no AC current is going through the schema; just DC voltage feeding an AC contactor. 

 

Basically, there are three distinct sounds I am wanting to differentiate; the slingshots, the flippers and the bumpers. I am aware of the washer "trick" with the Siemens Contactors. May consider that for the two Siemens flippers.
The claim is that the 24V AC contactors slam more than 10X louder than the 24V DC Siemens versions (the internal mechanism is different; one is a spring and the other is a magnet from what I understand). I've seen test videos that confirm the difference. This is why I have chosen them for the six bumpers; they have a lower, more-solid-sounding sound. I have disqualified the auto starter solenoids as an option because of burn-out issues. Yes, they are cheap, but seem to need replacement more often. Also, Zeb had stopped supplying them with his AIO feedback kit a while ago.  For the slingshots, I'm going with 12V solenoids that have a 60N throw on them, so they slam fairly hard with a higher note. 

Edited by dondi, 06 January 2020 - 06:54 PM.

[MikePinball]

Aren't there MOSFETs on PinScape AIO Power Outputs (4A max I believe)? Wouldn't this setup be the same as what these French guys are doing? Basically there is no AC current is going through the schema; just DC voltage feeding an AC contactor. 

The Pinscape All-in-One has thicker traces (2oz copper instead of the standard 1oz) and can cope with up to 8A. The MOSFETs can cope with even more.

 

The original append was about AC voltages. Providing you are using only DC voltages then you can drive any device you like up to a maximum of 50V DC. The fact that it is in fact a AC contractor is immaterial. I have no experience of doing this myself. But it sounds like other people have had some success.

[dondi]

I edited the above post to 4A after I had 8A in there. Went to the AIO thread and a few posts in, it said 4A, although I know you re-worked V2 with a bettern backplane later on.

Anyways, @MikePinball, it looks like I can do this running DC through the AC contactors. Getting good feedback from the French guys. However, they are suggesting using ChimeLogic for the outputs. I guess this is referencing the overheating mentioned above. I was looking at my schematics and see that I have only 5 Timed Outputs available (knocker & my Chimes use-up the other four).

 

Can I still wire these six AC contactors to the Power Output side and select ChimeLogic within the PinScape software?

[MikePinball]

However, they are suggesting using ChimeLogic for the outputs. I guess this is referencing the overheating mentioned above. I was looking at my schematics and see that I have only 5 Timed Outputs available (knocker & my Chimes use-up the other four).

 

Can I still wire these six AC contactors to the Power Output side and select ChimeLogic within the PinScape software?

 

Yes that was my guess too. It looks like feeding DC current to a coil meant for AC will need both more current and could cause earlier burnout. The ChimeLogic is software based and therefore is not foolproof unlike the true Chime outputs that have dedicated timers.

 

Given that these outputs are used a lot, it might be better to use timed outputs for all 6 (plus 3 for Chimes). That means moving the knocker to a standard output which might be just fine as it is not used that often. This is a risk but I think a smaller one than using the AC contractors with DC MOSFET drivers.

 

Pinscape AIO also supports adding Power Output boards and Chime boards. You would need someone to build and test a Chime board (even if it only had a few outputs fully populated). Or you could build a single dedicated single Chime timer circuit just for the one extra output that is needed and drive it from one of the existing other outputs on the Pinscape AIO.

[MaMikee]

Please don't drive AC coils with DC!  They will be in an over-current situation which is dangerous.  AC coils have very low ohmic resistance and rely on AC impedance to limit current.

 

If I published an Arduino circuit which used a servo to dump ether into your car's intake for additional power most people would steer clear.  Something about the invisibility of electricity doesn't create the same caution level.  "Sure, it's hot but my house is still here..."

 

I'm not sure why people are even considering this.  Louder?  Sure, put 100VDC on a 24VDC coil and it will be louder, but...  Plus even doing it with the correct voltage/frequency for the coil requires relays.  That would kill any cost savings and relays suck.

 

My DOF haptic coils are pretty loud, you can find them on eBay.  People really like them, very beefy.

 

 

[MikePinball]

My DOF haptic coils are pretty loud, you can find them on eBay.  People really like them, very beefy.

 

I couldn't find them. Do you have a link and more information?

[dondi]

My DOF haptic coils are pretty loud, you can find them on eBay.  People really like them, very beefy.

 

@MaMikee Didn't realize when you said "My DOF haptic coils...", that you meant you actually sell these on Ebay. I found the listings. Very interesting. I will echo MikePinball and ask if you have more information on these things? A video or something as well? Seems like a new animal to consider.

[MikePinball]

Please don't drive AC coils with DC!  They will be in an over-current situation which is dangerous.  AC coils have very low ohmic resistance and rely on AC impedance to limit current.

 

My DOF haptic coils are pretty loud, you can find them on eBay.  People really like them, very beefy.

I believe the guys who are using the AC coil approach have high wattage resistors in series which simulate the AC impedance to reduce the current. I'm not sure of the exact value but I could imagine a 62 Ohm 10W wirewound resistor ($0.80 ea) which reduces the current down to a more manageable 390mA. However I don't know how loud it is at this wattage and there is a huge amount of wasted power (and heat) in the resistor. BTW the 24V DC contactors operate at about this current too (~350mA).

 

Here is the ebay site for MaMikee's coils (thanks Dondi).

[MaMikee]

Good to know they limit the current somehow.  If they are getting more noise then they are still probably running more watts through the coils then they were designed for.  We all have different risk tolerance.

 

I'm sure my coils would be safe at 30 VDC and somewhat louder.  Much beyond that and you're on your own.  Many CPU chips run at 60 C or 140 F and are safe, but they would have trouble igniting.  I think coils would probably be safe at 120 F so maybe someone could see what voltage takes the coil to that temperature under constant use with an IR thermometer.  Still, that is "out of band" usage.

 

I think you can get better results by taking the "Bose" approach and working on mounting methods.  Like bass porting, you can mechanically amplify the sound you start with to change the user experience.  I haven't done too much in this area because each VPIN is basically a homebrew one-off.

[MikePinball]

Good to know they limit the current somehow.  If they are getting more noise then they are still probably running more watts through the coils then they were designed for.

Dondi said this: "The claim is that the 24V AC contactors slam more than 10X louder than the 24V DC Siemens versions (the internal mechanism is different; one is a spring and the other is a magnet from what I understand). I've seen test videos that confirm the difference."

 

Do you have a link to this video?

[dondi]

Do you have a link to this video?

 

Olivier upped the videos directly to FB, although it isn't a direct SiemensDC-to-AC contactor comparison. The videos are of the AC contactor and the 12V 60N solenoid. Here is the post to his Pincab Passion FB build log (where he starts talking about the AC contactors, "Test Position 10 x AC contactors" 6w back and I question him about them). Immediately after this, he posts two videos with the AC contactors in action.

Here is a direct Facebook discussion link I posted with the Monte ton Cab guys where I was asking about the AC contactors and how they were wiring them

 

Also, here is a direct link to Olivier's YouTube posted videos where he has done a bunch of solenoid/contactor testing videos

Edited by dondi, 11 January 2020 - 04:56 PM.

[MikePinball]

Olivier upped the videos directly to FB, although it isn't a direct SiemensDC-to-AC contactor comparison. The videos are of the AC contactor and the 12V 60N solenoid. Here is the post to his Pincab Passion FB build log (where he starts talking about the AC contactors, "Test Position 10 x AC contactors" 6w back and I question him about them). Immediately after this, he posts two videos with the AC contactors in action.

Here is a direct Facebook discussion link I posted with the Monte ton Cab guys where I was asking about the AC contactors and how they were wiring them

 

Also, here is a direct link to Olivier's YouTube posted videos where he has done a bunch of solenoid/contactor testing videos

 

 

I didn't see any mention of series resistors so they must be drawing a huge current for the AC contractors which is somewhat worrying.

 

I looked at several of Oliver's Youtube videos. This one in particular was just downright scary. He is testing the Ford starter solenoid 30 seconds in and blows his power supply and has to reset it. Then you can see visible sparks and smoke from the way he is manually connecting it. I mean if you are going to demonstrate something at Youtube, you should do it safely.

 

Not surprisingly the 60N and 80N solenoids have a hefty bump and might be a good long term replacement instead of using real Pinball coils. But the usual things apply about having reversed biased diodes, fuses, and hardware timer (e.g. Chime) circuits where possible.