90 replies to this topic

[rasm]

I ordered used contactors at ebay.There are a lot of matching offers and it should be the same for Canada. The 24v versions are a bit cheaper in Europe - about 10 EUR per contactor (I got 4 for 35). If you want a cheaper option check out car starter solenoids and/or the Chinese solenoids.

[SteveTheGeek]

Hi everyone !

 

  So I will receive in a couple of days eveything I need to add my first two contactors for the flippers : sainsmart relay board, 24V power supply, diodes, siemens contactors...

 

  Can I kindly ask you to validate if I understand the wiring correctly ? I'm soooooo not sure lol !

 

  - 5V+ Power Supply -> Sainsmart Control V+

  - Sainsmart Control Pin For Each Relay -> Ledwiz Output

  

  - Sainsmart Relay NO -> Siemens Contactor A2- 

  - Sainsmart Relay COM -> 24V Power Supply Ground

  

  - Siemens Contactor A1+ -> Power Supply 24V+

  

  - And the diode accross A1+ and A2- on the Siemens contactor (with the diode marker line towards A1+)

  

  Thanks for your kind help !!!

  

Steve

[SteveTheGeek]

Hi again !

 

  I wired everything last night, for reference, I forgot in my list the ground from the 5V power supply to the Sainsmart board.

 

  Please note the diode also protects from interference with the iPac, mine was acting up randomly when the contactors without diodes were activated. So diodes are really a must even with the relay board I wanted to wait to solder diodes because of some material missing

 

  So I can also confirm the Sainsmart board works well with the ledwiz !

 

Steve

[dboyrecords]

I used a 12v laptop power supply for my first 2 solenoids. Now I want to add 4 more and was planning to use 2 more 12v power supplies. Should I get 2 or 5 amp?

[maestro300]

I used a 12v laptop power supply for my first 2 solenoids. Now I want to add 4 more and was planning to use 2 more 12v power supplies. Should I get 2 or 5 amp?

 

Which solenoids did you get?   The Chinese ones?   What do you think of them?

[dboyrecords]

My sainsmart is on a slow boat from China. I have 5 car starters but currently just 2 on flippers. They share a 12v laptop power supply just fine!

Hopefully next week or so I'll get it together. Been reading up on dof, kind of intimidating!

[jkimbrell]

This could be a dumb question but why would you need diodes on the actual solenoids when using the sainsmart relay board as it already has two protective diodes on each relay?  What function could the additional diode at the solenoid provide? The diodes on the relay board protect the "trigger" coming to/from the LEDwiz.  Please explain

[SteveTheGeek]

In my case, firing the contactors without a diode was randomly making my iPac fire random buttons once in a while, thus exiting the table. I've seen another post from Zeb confirming he's seen this happen too. He said it the contactor was creating some interference...

 

Adding the diode solved this on my side !

Edited by SteveTheGeek, 06 June 2014 - 06:38 PM.

[dboyrecords]

Just received my sainsmart! But am unsure how to wire it up to solenoid... can someone explain? Thanks

[SteveTheGeek]

Just a look a couple of posts earlier in this thread, I explained how I wired it up, should be similar with solenoids !

[dboyrecords]

I was confused by the 3 inputs per relay. Looks like I want no A, hot to B and solenoid to C.

[jkimbrell]

In my case, firing the contactors without a diode was randomly making my iPac fire random buttons once in a while, thus exiting the table. I've seen another post from Zeb confirming he's seen this happen too. He said it the contactor was creating some interference...

 

Adding the diode solved this on my side !

 

That's strange because in the wiring scheme you describe above, your contractor load should be completely isolated by the relay and the relay coil input from ledwiz is already protected by an integrated diode on the relay board.  

[maxxsinner]

You are correct that the contactor load is isolated by the relay, but the problem is when the contactor/solenoid has the power disconnected. 

 

The back EMF that occurs when an inductive load is switched off can create voltage spikes in areas where we don't want them and as was happening in Steve’s example, circuit boards can see these spikes as an input.

 

A diode across the coil of the contactor will allow the back EMF to circulate back through the coil until it has dissipated.  - http://en.wikipedia....i/Flyback_diode

Edited by maxxsinner, 09 June 2014 - 08:41 PM.

[zebulon]

Even though the coil on the contactor is isolated, the coil on the relay will need a diode to block the EMF that it creates.

[SteveTheGeek]

As they said Thanks guys, this was over my head a lot

Envoyé de mon Nexus 5 en utilisant Tapatalk

[maestro300]

Bump on the first post of this thread-- Has anybody ordered and tried the 12V solenoids yet?   I'm about to place the order and wondering if they have enough power to make bumper/slingshots sound realistic or if I need contactors.    Thanks!

[rasm]

I ordered a set of them over one month ago and am still waiting. I will report my impressions as soon as possible.

[spahner]

 

You are correct that the contactor load is isolated by the relay, but the problem is when the contactor/solenoid has the power disconnected. 

 

The back EMF that occurs when an inductive load is switched off can create voltage spikes in areas where we don't want them and as was happening in Steve’s example, circuit boards can see these spikes as an input.

 

A diode across the coil of the contactor will allow the back EMF to circulate back through the coil until it has dissipated.  - http://en.wikipedia....i/Flyback_diode

 

 

Hello!

 

I'm building my first Visual Pinball cabinet, would it be ok to use 1N4001 diodes on the Siemens 12v contactors instead of 1N4007?? Only difference as far as I can see is the reverse voltage is rated to 50V on the 1N4001 and 1kV on the 1N4007. (I don't know how much is needed.)

Edited by spahner, 03 October 2014 - 12:33 PM.

[Dozer316]

Hi there, I'd recommend the 4007 in preference to the 4001 if it can only take 50v. I don't know the exact back emf voltage spike level the siemens contractors peak at when the field collapses but with the automotive solenoids I am using the original diodes I had in place which I think from memory were 100v or so were failing. When I went the 4007 everything was fine.

[maestro300]

I use 1N4001 and 1N4007's with my 12V solenoids-- no issues at all.    1N4001 is 50v @ 1A.    If you have 1N4007's then I would recommend them over the 1N4001's though (I just didn't have a choice in the 25 pack variety I got)    The solenoids draw 450ma if I remember right.