56. Flashers and Strobes
Flashers and strobes are extra lights on your cab to reproduce the
bright flashing light effects of the real machines. I personally rank
flashers in the top tier of must-have feedback devices, as they add a
huge amount of excitement and realism to the playing experience.
Pinball machines have always used blinking lights to attract players
and add to the visual appeal of the game. The light shows became more
sophisticated when software started controlling the games in the 1980s
and 90s, as complex lighting patterns could be programmed and
coordinated with the game action.
One of the key light show components in the 1980s and 90s machines is
the "flasher" light. A flasher is a bright lamp in a plastic dome,
usually situated above the playfield, maybe near a ramp or other
vertical element sticking up out of the playfield. Games from the 80s
and 90s typically have five or six flashers distributed around the
playfield. As the name implies, flashers light up briefly at key
times to create a brilliant strobe effect, to underscore an event
in the game and add drama.
Flashers in real pinballs: alongside the
right ramp in Earthshaker; behind Rudy in Funhouse
The flasher lights from the original games are, of course, reproduced
on-screen in the Visual Pinball versions and other simulator versions.
They appear in the video version just where they would have been on
the real playfield, and they light up when they're supposed to.
That's fine for desktop play, but when you blow it up to life size in
a pin cab, it becomes more apparent that they're artificial; the video
version just isn't as bright as the real thing.
That's why many pin cab builders include actual flasher lights on
their cabs. Rather than relying entirely on the on-screen video
renditions of the flashers, you can supplement the video display with
a set of real flashers, which produce the same brilliant light as the
Related to the flashers is the "strobe" light. This is an
embellishment thought up by the pin cab community, not something you
find on real pinball machines (not commonly, anyway). It usually
takes the form of a very bright white light somewhere in the player's
line of sight. The DOF software will flash this briefly (thus the
"strobe" monicker) at dramatic points in the game play. This might
just seem like one more flasher light, and in broad terms, it is. The
only reason for calling it out as a separate device is that it's
usually implemented with a much brighter light source than the regular
flashers, so that it produces a particularly dramatic burst of light
at appropriate moments.
In the real games, flashers are arranged around the playfield in
different places in each game. There's obviously no way a virtual pin
cab can reproduce the exact placement of the original flashers in
every game (other than with the video renditions that we've already
decided we want to supplement). We can't even move them around per
game; we have to pick a fixed set of locations. So the usual
arrangement is to group a set of flasher lights together in a "flasher
panel", usually arranged in a straight line across the width of the
There's no fixed rule about how many flashers you use or where to
place them. It should go without saying, but it's your cab, so it's
your call. But given the constraints, there are some common
arrangements that most cab builders end up using. Let's look
at the options.
Number of flashers: Most pin cab builders use a panel with
three or five flashers.
What's magical about the numbers 3 and 5? History, mostly. The DOF
Config Tool database has specific support for 3- and 5-flasher setups,
because those are the most common setups that people build. (And now
everyone goes with those setups because they're what's supported.) The
5-flasher setup also has a somewhat deeper significance in that it
maps well to the original physical flasher layout in most real tables.
Most of the 1980s and 90s machines used about five flashers total, so
a 5-flasher panel lets DOF map the flasher effects from the original
games directly to your physical lights.
You can build panels with any number of flashers you want, but a
3- or 5-flasher setup is easiest to work with because of the
pre-programmed DOF support.
I'd recommend the 5-flasher setup if you're building a full-size cab,
since it will easily fit and will produce the most interesting light
show effects. The 3-flasher setup is mostly for mini-cabs where
there's not room for five.
Placement: Once you have your panel of three or five
flashers, the possibilities for where to situate it become
fairly apparent based on the space available in your cabinet.
The most common places are:
- At the back edge of the playfield TV. This is the most common
placement, because it answers the question "what should I do
with the extra space behind my TV?" that most cab builders are
faced with. Nearly all pinball cabinets
designs (even the "widebody" plans) are longer and narrower than a
standard 16:9 TV, so there's usually some extra front-to-back
space to fill, typically between 3" and 6".
You can position the panel so that it lies flat in the same
plane as the TV, or you can tilt it up at an angle, if you left
any vertical space between the playfield and the glass cover.
My panel is tilted up at about a 30° angle to fill the
vertical space (see the photo below).
- Vertically, on the inside back wall of the cabinet above the TV.
Some people prefer this arrangement because the lights point more
directly at the player, which might slightly reduce reflections from
the glass cover.
- On the front of the backbox, in the speaker panel area just below
the DMD. If you positioned your TV at the very top of the cabinet
with no room between the TV and glass cover, you probably can't fit
flashers inside the cabinet. You can position them outside the
cabinet instead, on the front of the backbox.
- Across the top of the backbox, near the front edge. I have an extra
set of five flashers here on my cab. This is a good place for a
supplemental set of flashers, but I wouldn't recommend it as the
location for a lone set, since it's not in the player's line of sight.
That greatly reduces the impact. It does add to the effect for
bystanders, though, which is why I like it as a secondary location.
My flasher panel. Five flasher domes are
distributed across the width of the cabinet. The panel is
at the back of the playfield TV, tilted up at about a 30°
angle to the plane of the TV, so that it fills both the
horizontal and vertical gap at the back of the cabinet.
Building a flasher panel
LEDs: For the full effect, you'll want to use an RGB LED
for the flashers. This allows the software to control the color
emitted. An RGB LED has separate elements internally for red,
green, and blue light (the "R", "G", and "B" of the name).
The type that most people use in pin cabs can be found on eBay
by searching for "star base LED" or "3W LED RGB". They look like
The type on the left is the "star base" type. These come with a metal
base that serves as a heat sink and makes the wiring a little easier.
The type on the right is actually the same LED, just without the base.
You can buy them either way. Most people think the type with the base
is a little easier to work with.
These are sold in individual colors as well as RGB, so be sure to
order specifically the RGB type. All of the parts I've seen for these
on eBay are the same basic device, so there's not too much risk of
finding a wrong part that looks similar, but here are the approximate
electrical specs to look for just to be sure you have the right thing:
- Red channel: 2.2 to 2.4V, about 400mA
- Green channel: 3.2 to 3.4V, about 400mA
- Blue channel: 3.2 to 3.4V, about 400mA
Most pin cab builders use the same domes
used on the real pinball machines for their flashers. They come
in two main types, which are different only in how you attach
them. Here are the Williams part numbers:
The screw tab type is a little easier to install; the twist-on type
looks a little cleaner since the fasteners are hidden under the dome.
You can easily make either type work as long as you plan for it.
The domes come in various colors (red, purple, amber, etc.), but for
pin cab purposes, you almost always want the clear type, since we use
them with color-changing RGB LEDs. If you want a particular color for
some reason, the last two digits of the part numbers above are the
color code for "clear", so you can find the other colors by searching
for the part number prefix without the -13 suffix.
Voltage supply: Plan on supplying the flasher LEDs from a
5V power supply.
A lot of new cab builders find LED voltage specs confusing. LEDs
always quote a "forward voltage", and it's always something weird like
2.2V or 3.4V. And it's usually a range, like 2.2-2.4V. Does this
mean that you're supposed to find a 2.2V power supply? Fortunately
not! The "forward voltage" for an LED isn't
the supply voltage
required. It's the amount of voltage that the LED "drops" when
operating, which is sort of the amount it uses or consumes. That's
why it's often quoted as a range; the manufacturer is just saying that
the exact number varies a little bit from one individual part to the
next, but it should always be in this range, and will usually
gravitate to the middle of the range. What does this mean for the
supply voltage, then? It's really simple: the supply voltage can be
any voltage higher than
the forward voltage. So if the forward
voltage is "3.2-3.4V", it means that you can use pretty much anything
higher than 3.4V. It's best to pick the lowest conveniently available
voltage higher than the required minimum, because the higher the
voltage, the more energy will get burned up in heating the resistors.
In a pin cab, you usually have a 5V supply readily available, (see
Power Supplies for Feedback
), so 5V is the best option for almost every
LED. If you had a 4V supply or a 3.7V supply, that would be better
still, but those aren't typical voltages in a pin cab; 5V is what
we usually have readily at hand.
You might read advice on the forums to use a 12V power supply for the
flasher LEDs. Ignore that. It's best to use the lowest conveniently
available supply voltage above the LED's "forward voltage" spec.
Using a 12V supply just burns up all of the extra voltage in resistor
heating, which forces you to use physically larger resistors that can
tolerate all of the extra waste heat. A 5V supply lets you use
smaller resistors that waste less energy.
Resistors: The star base LEDs are bare LEDs that do not
include any sort of built-in current regulation. This means that you
must include separate resistors in the circuits when wiring them.
It's important to choose the correct type of resistor for each
color channel. LED Resistors
explains how to choose,
and includes a calculator to determine the correct Ohms and Watts
value for each.
The resistors have to be wired into the circuit in series with the
LED. They can go on the (+) side or the (-) side; it's exactly
the same either way.
You can wire the resistor for the LED on
the negative side or positive side, whichever is more
convenient for your setup. It's the same electrically
The red, green, and blue channels are independent devices, so each
channel needs its own resistor. The channels will have different
resistance values, too; that's why they quote the "forward current"
and "forward voltage" separately for each color.
Pay attention to the wattage value that the resistor calculator
reports, and be sure you buy resistors with at least the required
wattage. This is not some kind of "detail for nerds" that
you can ignore; it's part of the spec for what you need to buy.
Here's a simple circuit board design for the resistor panel. This is
designed to be used with a ribbon cable connector to the output
controller board. The pin layout of the 16-pin connector (at the
bottom of the board as pictured below) matches the pin layout of the
Pinscape expansion board RGB Flasher connector, so you can
conveniently connect this directly to the expansion board with a
ribbon cable. You can also easily use this board with non-Pinscape
output controllers; you just have to program the controller so that
the LED channels match the pins on the connector.
Here are the EAGLE plans, if you want to have this board manufactured:
You can have it made in lots of three by OSH
for about $16, with an extremely simple ordering process (just
upload the .BRD file from the ZIP above). You can have it made
more cheaply per board at PCB makers like Elecrow, but they have larger
minimum order sizes and require you to generate Gerber files. That
procedure is explained in Fabricating the Expansion Boards
To assemble this board:
- Install a 2x8-pin 0.1" pin header as shown in the picture
- If you use a shrouded header for the 2x8 connector, make the sure
the keying slot on the shroud is aligned properly for your ribbon
cable; see 0.1" Pin Headers
- Figure the resistor values required as explained in LED Resistors
- Be sure to pay attention to the wattage calculation in that section, and
use resistors with at least the required wattage specs
- The board is designed for resistors up to 4mm in diameter and
up to 12mm in length (the gigantic squarish "cement" resistors won't fit)
- Install the resistors in the R_xx slots: R_1R is the resistor
for LED 1 RED channel, R_2B is LED 2 BLUE, etc
- Resistors aren't polarized, so it doesn't matter which direction
you install them
- I'd solder hookup wires from the boards to the LEDs directly to the
edge connector terminals; 1R is for LED 1 RED, 2B is LED 2 BLUE, etc
- If you prefer, you can install single-row 0.1" pin headers on the edge
connectors, but I don't think that's necessary in this case, because I'd
consider this board to be an integral part of the flasher board that can
be hard-wired to the LEDs
- If you're using the Pinscape expansion boards, simply connect the
resistor board to the RGB Flashers header using a 16-conductor ribbon
cable with a 16-pin IDC plug at each end; see Ribbon Cables
for help building these cables
- When plugging in the cable, be sure that the ribbon cable is oriented
so that Pin 1 on the expansion board connects to Pin 1 on the resistor
board (Pin 1 on both boards is marked by the little triangular arrow
next to the header)
Building the panel: I went with a simple design for my panel.
- I started with a piece of 3/8" plywood, cut to the inside width of
my cabinet and a height that I measured to fit the available space
where I planned to install it.
- I drilled five 1/2" holes at regular intervals, where I wanted to
place the lights.
- I soldered four wires to each of the five star LEDs: one wire to
each of Red(-), Blue(-), and Green(-), and a fourth wire that I
connected to all of the (+) terminals. As described in
Feedback Device Wiring, the standard wiring plan for all devices
is to switch on the (-) side, so the (+) side is always connected
directly to power and can thus be daisy-chained across all devices
that share the same voltage.
- I then installed the LEDs in the pre-drilled holes, holding them in
place with little metal clamps. The clamps aren't anything standard;
they're just something that I made custom by cutting them out from a
piece of sheet metal from Home Depot.
- I ran the wires from the LEDs to a small circuit board containing
the resistors (see above). This is just an ad hoc circuit board I
made for the cab. You can just wire the resistors in-line through the
wires without a circuit board if you find that easier.
- On the front side of the board, I attached the plastic dome with
Finishes for the panel:
Most people just paint their panels in
the same color as the inside cab walls, usually black. I used
custom-printed adhesive decals that I had made at the same time as the
decals for the exterior of my cab. See Cabinet Art
Heat sinks: Some people use large heat sinks with these LEDs.
I don't personally think it's worth the trouble, because flashers are
activated intermittently, for brief periods. Plus, the metallic star
bases already provide a moderate degree of heat dissipation. If you
were leaving these LEDs on at full power for long periods, heat sinks
would be warranted, but they're not necessary in this application.
If you want to use heat sinks anyway, you can find a variety of
suitable products on eBay. Attach them to the back of the star
base with thermal paste.
Wiring to the output controller:
Follow the general plan in
Feedback Device Wiring
to connect the LEDs to your output
controller. Connect the (+) side of each LED to the +5V from your
power supply, and connect the (-) side to an available port on your
output controller. Keep in mind that each channel requires a resistor
(see above) in series with the LED, inserted either between +5V and
the LED (+) terminal, or between the output controller port and the
LED (-) terminal.
The DOF Config Tool requires that you use consecutively numbered
output ports for each Red-Green-Blue group, in that order.
For example, if you wire the RED channel of Flasher #1 to output port
#8, you must wire GREEN to port #9 and BLUE to port #10.
In the DOF Config Tool
after you've done the basic setup for your output controller,
go to your Port Assignments page. For each flasher LED in your
setup, find the port number for that device's RED channel, and
set it to the appropriate flasher device:
- For a 5-Flasher setup, the flashers are labeled, from left to
right, "5 Flasher Outside Left", "5 Flasher Left", "5 Flasher Center",
"5 Flasher Right", and "5 Flasher Outside Right".
- For a 3-Flasher setup, the flashers are labeled, from left to
right, "3 Flasher Left", "3 Flasher Center", and "3 Flasher Right".
When you select the appropriate "5 Flasher" or "3 Flasher" device for
the RED channel's port, the Config Tool will automatically assign the
next two output ports in sequence to the GREEN and BLUE channels for
the same device. This is why you had to physically wire each LED to
three consecutively numbered ports in Red-Green-Blue order. It's just
the way the Config Tool thinks about RGB, so you have to do the wiring
to match its expectations.
Pinscape expansion boards: If you using the Pinscape expansion
boards, you should connect the flashers to the dedicated Flasher
outputs on the main board. These outputs have enough power handling
capacity for about three sets of flashers in parallel, if you have
multiple sets (such as my arrangement with the main flasher panel at
the back of the cabinet, plus a second set on top of the backbox).
Strobes make a nice accompaniment to flashers. Strobes are simply
bright white lights, usually much brighter than the flasher lights,
that the software can light up occasionally for particularly dramatic
events in the game.
Unlike flashers, strobes are typically monochrome, not RGB. They're
just plain white lights. This makes them a little quicker and easier
to set up since you only need a single output port to control them.
One question that new cab builders always ask is whether you need some
kind of special timed bulb that handles the rapid flashing effect.
The name "strobe" certainly suggests this. The answer is no: the
flashing effect is handled entirely by the DOF software. All you need
for the physical device is a bright white LED.
Parts: The device that most pin cab builders use for strobes
are small but bright LED panels designed for automotive use (emergency
lighting, spotlights, etc). They can be found on eBay by searching
for 22 LED white strobe. (This search might also turn up some
"22 Inch" LED light bars for trucks. Ignore those. You're looking
for the smaller "22 LED" products.) The ones you're looking for look
Since these are designed to be installed in cars and trucks, they
usually come with a separate control box, which lets you blink the
lights in various flashing patterns. You don't need these
control boxes for DOF - just discard the control box and plug the LED
directly into your output controller. That will let DOF control the
flashing effects directly. (This also means it's perfectly fine to
use an LED that doesn't come with any sort of control box.)
Positioning: A lot of people put a pair of the 22-LED
strobes on their flasher panel, usually one at each outside edge.
Others put them on top of the backbox or in the speaker panel area.
I put mine on top of the backbox, facing forward (facing the player).
I'm happier with that location than in the main flasher panel because
I find them too bright to have directly in your line of sight while
playing. Having them on top of the backbox makes the strobe effect
suitably dramatic without blinding the player every time they fire.
Power supply: Check the specs on your specific product to be
sure, but the standard power requirement for strobe panels like the
ones described above is 12V DC. The same is true for almost anything
made for automotive use, since that's the standard car "cigarette
LED resistors: Not needed for the typical 22-LED panel. These
are meant to be plugged directly into a car's 12V power supply, so
they have the necessary resistors built in.
- Connect the 22-LED panel's (+) terminal (usually the red wire) to
the +12V power supply (the yellow wire from your secondary ATX power supply)
- Connect the LED panel's (-) terminal (usually the black wire) to
an available port on your output controller
- If you bought one of the car-and-truck strobes that comes with a
blinker control box, discard the control box and connect the wires
from the LED panel directly to your output controller (LedWiz/Pinscape/etc).
DOF will handle the flashing effects, so you don't need any separate blinker
control box; including it in the circuit will just interfere with the
wider range of effects DOF can create.
No additional parts are needed with these (in particular, no resistors
The typical 22-LED panels require about 500mA. This is just barely
within the safe range for an LedWiz output, so you can connect it
directly to an LedWiz. Don't connect two panels in parallel to
the same LedWiz port, though, as this would require 1000mA, which is
double the LedWiz's safe limit.
Pinscape expansion boards: You can connect a 22-LED panel to
the dedicated "Strobe" output, to any RGB Flasher port, or to a power
board port. Any of these ports will handle two of the 22-LED panels
wired in parallel.
In the DOF Config
, go to your Port Assignments page. Find the output
controller port number where you wired the strobes. Assign this