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Arcade Collecting => Pinball => Topic started by: telonio on April 18, 2022, 03:27:11 pm

Title: Raspeberry pinball pop bumper connection question
Post by: telonio on April 18, 2022, 03:27:11 pm
I have the parts (flippers, slingshots and pop bumpers, all full assemblies and I want to create a pinball prototype using raspberry pi3. I am bit confused about the power of these components and the switches.

For example pop bumpers.

I will use a 48v power supply for the pop bumpers and the switches within pop bumpers will be connected to raspberry pins. What I don't understand is that pop bumper will be activated automatically when the ball hits it and the switch is just for scoring or the switch tells the coil to active and I somehow have to find a way to connect the coil to the raspberry?

Thanks
Title: Re: Raspeberry pinball pop bumper connection question
Post by: lilshawn on April 18, 2022, 06:53:13 pm
this is a bigger project than you realize.

I don't believe a raspberry pi has enough IO to do anything but a very VERY basic pinball with only a few features.

every light is going to need an IO pin*
every switch needs an IO pin*
every solenoid needs an IO pin
every flasher needs an IO pin


even a moderate pinball has 120 to 150 IO going on... and even that's with multiplexing all the lights and switches.

*(a 8x8 switch matrix and a 8x8 or even an 8x16 lamp matrix is often used to reduce IO requirements) with a dedicated switch set for starting and flippers and dedicated IO for all solenoids

you are looking at something more like an arduino mega or some kind of GPIO expander for a PI at the very least to have enough

you are not going to be able to power any lamps or solenoids directly. you are going to have to build fet driver boards to run them.

in all modern pins, the switches only feed back to the CPU board and the CPU board sends the enable signal to the FET of the appropriate solenoid to trigger it. no high voltage switching is done. it's all done in programming.

you'll also have to program in PWM if you need to keep a solenoid on more than 250ms (such as a gate or flipper.) they cannot be driven full voltage 100% duty cycle... they will fry in a second or 2.

>48v power supply

typically the only solenoids that require this high voltage is flipper and poppers. all the others like slings, VUKs, Flashers all run ~24ish volts. so you'll need to either account for that in your driver/PWM programming or have a dual voltage supply (or a buck converter capable of several amps capacity)
Title: Re: Raspeberry pinball pop bumper connection question
Post by: telonio on April 19, 2022, 07:00:57 am
Thank you for the reply it helped me a lot.

I want to make a prototype so not too much IO inputs wanted for now. I have to think about  the connection of a pop bumper with 24v and a voltage divider to 5v for a Raspberry or Arduino.

One more question please.

About the coils of the flippers. They will be connected to the processor with also voltage divider 48v to 5v. But if I keep pressing the buttons for the flippers, 48v will be keep going to the coils?
Title: Re: Raspeberry pinball pop bumper connection question
Post by: pbj on April 19, 2022, 02:17:00 pm
Use the PI to drive a relay.  Use the relay to toggle high voltage from a separate power source to the solenoids.  I've never heard of an electronic pinball machine using the same voltage rails to drive both logic and mechanical action. 
Title: Re: Raspeberry pinball pop bumper connection question
Post by: lilshawn on April 19, 2022, 04:01:43 pm
this is not going to be a beginner project.

bruh... :o 48 volts to a coil leg... other coil leg to mosfet...other fet leg to ground.... pi to gate of mosfet to turn it on and off and essentially switch the ground of the coil on and off. flyback diode on the coil to keep from cooking the fet from field collapse.

thing about 48 volts has anything to do with a microcontroller or pi.

it sounds like you might want to read through some basics of operating high power solenoids and stuff using relays and transistors and FETs with the pi first. this isn't rocket science, but its more than just plotzing a coil on a pi and make it go brrrrrrr