Voltages and Power - The Mission Pinball Framework (2024)

A pinball machine uses multiple different voltages for differentpurposes. You need at least one power supply unit (PSU) to transform theAC power to multiple DC rails. SeeWiring and Connectors for more detailson the wire thickness and connectors to use for the different powerrails below.

Video about electronics basics:

Primary side - 230/110V

At the mains your machine usually runs at 230V or 110V depending on theregion. Some PSUs are able to work with both voltages. Sometimes thereis a switch to select the input voltage. In other cases a PSU might onlywork with a certain input voltage. Make sure to check this beforeconnecting the PSU to the mains.

In case you run a traditional transformer you usually have to wire thewindings differently depending on the input voltage. If you get thiswrong the output voltages might be different or the transformer mayburst into flames.

In any case it is a good idea and common practice to add a fuse beforeyour PSU or transformer in case anything goes wrong. This is for yourown safety and for the safety of your neighborhood because if stuffstarts burning it might cause a lot of damage.

High Voltage - 48V to 80V

High voltage (HV) is used to drive coils in your machine. In modernmachines 48V is used which technically classifies as low voltage in mostcountries around the world (it is still not safe to touch and can killyou). This is preferred if you start a new design as PSUs for 48V arereadily available at a good price. Most machines use supplies witharound 6A to 10A.

Older machines used transformers with 70V to 80V. Those are moreexpensive, heavier and harder to get nowadays. They are generally notrecommended for new designs. If you want to produce a machine this willalso be harder to certify in most countries. Some people use 24Vsupplies which technically works but is not recommended because coilstend to be quite weak and unreliable in those settings.

A large capacitor might help to keep this rail stable since pulsing andPWMing coil causes large electric and magnetic spikes. In some cases aPSU might turn off while driving coils without a capacitor on this rail.In other cases pulses might be unstable because the voltage will droptoo much during the pulse (seems to be common with 24V supplies). If youare increasing pulse times and there seems to be no change in the powerof the coil you are likely experiencing the second issue. Adding largecapacitors or using a power entry board (see below) is recommended inthose cases.

You want to use at least one fuse on the HV rail to prevent coils fromburning. Most coils will start burning after a while if you enable thempermanently without PWM (see hold_power inground_and_appliance_classes for details). You do notwant that. Instead the fuse should trip and cut the power. It might bewise to use multiple fuses (e.g. one per bank of coils).

Common power supplies for 48V:

• Meanwell SP320-48 - Used by Stern Spike (not recommended because it is a bit too weak)
• Meanwell RSP500-48 - Used by Stern Spike 1 (starting from Ghostbusters) and Spike 2
• Meanwell SE-600-48 - Used by Spooky

Common power supplies for 70V - 80V (not recommended for new designs):

• AnTek PS-4N70R5R12 - 70V + unregulated 5V and unregulated 12V

Light Power

Your lights will require a lot of power. Depending on the type of lightthe voltage might differ. Traditional incandescent bulbs need somethingaround 12V to 24V. LEDs usually run at 5V (sometimes 12V). Make sure tounderstand how much power you need for your lights. Then calculate whichwires, connectors, PSU and fuses you need. This is very likely ahigh-current setup and standard connectors with thin wires willcertainly cause problems (or fire) in your machine.

For instance, every LED will draw around 20mA. Triple that for RGB LEDs.With 80 RGB LEDs for inserts and 80 RGB GIs you will end up at 10A poweror 50W. Most connectors are rated for less than 10A and you will seesome voltage drop with thin wires (check the resistance).

Make sure this is properly fused since this may easily burn down yourmachine.

Common power supplies:

• Standard ATX power supplies - People use them, but they're not generally recommended for pinball machines
• Meanwell SP/MW for 12V or 24V - Precalculate your current and get one with some headroom

Display Power

RGB DMDs usually need either 5V or 12V and might draw a few amps at fullbrightness. Traditional DMDs might need very high voltages. Definitelyask a professional before getting started with traditional DMDs.

As with any power rail: Add a fuse.

Common power supplies (for 12V):

• Standard ATX power supplies
• Meanwell RD65A - A cheap 5V and 12V supply

Logic Power

In most cases this will be 5V and 12V. Most systems use 12V for switchesand 5V to power logic components. In most cases you don't need manyamps on those rails. It might be wise to run separate 12/5V rails forlogic components and light/display power to prevent problems withinterferences.

As with other rails: Add a fuse to be safe.

Common power supplies (for 12V):

• Standard ATX power supplies
• Meanwell RD65A - A cheap 5V and 12V supply

PC Power

Most machines run embedded PCs which come with their own PSU. Sometimesthey run off 5V (such as the Raspberry Pi). Others use standard ATXpower supplies. See ground_and_appliance_classesfor details about power on/off.

Electromagnetic Compatibility EMC/EMI

You need to make sure that your machine complies with regulations andwill not disturb police radios/air traffic control or your neighborsWifi. Especially pulsing or PWMing coils will cause a lot ofinterferences. This might cause RF emissions and make you a lot ofenemies. The most important step to mitigate EMI is to run your powerand return wire in parallel and make them the same length. There will bea magnetic field between HV and GND to your coil when current flows. Ifcurrent changes, the field will change and you will transmit signalwhich is what you want to avoid. Additionally, add free flow diodes toyour coils to prevent self-induction voltage from travelling back toyour driver board and PSU (which will transmit another signal).

EMC is a complex topic. If in doubt consult an electic engineer.

Common Ground

In general, it is preferred to connect the ground at the PSUs than belowthe playfield. Then run a separate ground for each power rail from thePSU to the playfield.

Interferences on the ground of the HV rail might cause problems in otherrails. Especially for serial LEDs and logic power. In case you run intothose problems consult with an electric engineer. The right capacitorsand the right wiring might help with this case for example.

Common "ground" generally refers to the neutral wire of your PSU whichshould not be confused with ground/electric earth. SeeGround and Appliance Classes for detailsabout ground vs neutral.

Power Filter Boards

Some vendors sell power filter boards which help you to build yourdifferent power rails. Additionally, those boards allow you todisconnect components at a central location. Usually, those boards willalso connect all ground for you.

Some common boards:

• Multimorphic Power Entry Board
• FAST Power Filter Board
• Spooky/PBL Power Entry Board (part number: #600-0253-00)
• OPP Power Filter Board
• Stern Spike Power Distribution Board (part number: 520-5343-01)
• CobraPin Pinball Controller has a built in power filter.

Have a look at the PCB section ofhardware.missionpinball.orgfor DIY designs.