The PFx Brick has a wide portfolio of emergency vehicle flasher light effects. There are nearly 40 different different sequences each with different flash rates and styles. This enables builders to configure light outputs to match a wide variety of emergency vehicles used around the world and from different eras. A key feature of emergency vehicle flashers is the roof mounted lighting; implemented either as discrete lights or more commonly mounted into a light bar structure on the roof. In addition to the roof/lightbar flashers are auxilary flashing lights. These auxilary lights vary widely in terms of quantity and location among all emergency vehicles. Examples include side mounted flashers, radiator grille flashers, headlamp cluster flashers, etc. Auxilary flashers are often synchronized with one or more of the lightbar flashers and may or may not have the same flashing pattern. The PFx Brick provides a variety of functional flashing light outputs for all emergency flasher types in order to match a wide variety of prototypical emergency vehicles. The builder does not have to use every light output and may chose any combination which best suits their model.
The best way to see how these flashers work is to see them in action! This video shows the police interceptor in action:
The PFx Brick typically uses 7 of the 8 dedicated light channels for emergency vehicle flashers. The definition of each light channel is common for all of the emergency flasher styles and is shown in the diagram below. Also shown are a few examples of flasher lights with the light channels labeled.
The lightbar or roof mounted lights consist of a group of 4 lights which flash in variety of different styles. Often, these lights will be co-packaged into a roof mounted light bar. Two lights are intended for the left side of the vehicle and another pair is intended for the right side. Each left/right pair can have an inner and outer light. This allows light flashing sequences to alternate from left to right or from inside to outside depending on the style. For more simple applications, one of each of the left and right pairs can be used, e.g. just the outer left/right pair.
Two very common types of lightbar flashers are the so-called “Twinsonic” and “Whelen” style light- bars. These are named after the trade-marked products of Federal Signal and Whelen Engineering respectively; manufacturers of emergency vehicle lighting products. These style names are intended to be representative and not exact copies of any particular lighting product. The “Twinsonic” style light bar physically consisted of rotating mirrors around a light source and were common in older or heritage emergency vehicles. The rotating light effect is simulated with periodically variable brightness and has a “softer” flashing effect. The “Whelen” style lightbar is designed to simulate the flashing effects of modern and contemporary LED strobe-type emergency flashers. These light bars have many different strobe-like patterns and sequences. The PFx Brick includes most of the typical sequences available from this style of emergency flasher.
Many emergency vehicles incorporate additional flashing lights to those mounted on the roof. These can consist of flashers which duplicate the flashing sequence from the light bar or flash periodically synchronized with the alternating effect of the lightbar. The PFx Brick provides auxilary flasher outputs in order to connect lights which best represent the flashing light configuration of a particular vehicle.
The left/right auxilary 1x flashers flash periodically at the specificied rate alternating from left to right. The single auxilary 2x flash output flashes periodically at twice the specified flash rate. The 1x and 2x auxilary flashers are simple periodic flashers and do not exhibit the complicated flash sequences of the light bar. They are however synchronized with the light bar flash rate.
In order to showcase the awesome emergency vehicle lighting effects, I decided to build the quintessential North American police car: the Ford Crown Victoria police interceptor. I built the model using reference photographs and wanted to keep the scale of the vehicle within a typical 6-studs wide. The car was wired with operating head/taillights, reverse lights, headlight flashers and of course the roof light bar. Amazingly, the PFx Brick, speaker, and light wiring all fit within the car. A Power Functions extension wire discreetly feeds out of the bottom of the car to connect to an external battery box. A wiring diagram of the police car is shown below.
The PFx Brick was configured to activate the various lighting and sound effects using a dual joystick remote control. The remote actions were configured as follows:
As a follow up to the previous blog post about this model, a short video showcasing its features is now available. The addition of the PFx Brick transforms this modest helicopter into a dramatic and exciting model! In the video introduction, a second PFx Brick used to create flickering fire light Fx on the roof of the shelter. One of the interesting features to note is how the helicopter startup process is initiated with one remote control action. This single action activates:
- Flashing navigation beacon light
- Engine startup sound effects
- Motor speed set to 75% max with an acceleration factor
Combining these actions makes controlling a model that much easier and fun!
We have integrated the PFx Brick into many different LEGO® models of various shapes, sizes, and themes. The most interesting and challenging integration projects are small models with very little interior space. I think this challenge makes the result that much more satisfying! Shown above is the LEGO® City Fire Helicopter (60108) with a PFx Brick used to full effect.
- Motor driven main rotor
- Tail rotor navigation lights
- Anti-collision strobe beacon light
- Nose wheel headlight
- Port/starboard emergency flashers
- Speaker with various sound effects
All of the active lighting effects can be toggled on or off using a Power Functions remote control. The main rotor speed is also controlled via the remote. The motor is configured such that the top speed is limited to about 50% full speed to prevent excessive model vibration. Furthermore, the motor acceleration and deceleration have been configured so that the rotor has realistic slow acceleration to emulate the high inertia of a real helicopter's rotor blades. Lastly, the model has sound effects for helicopter rotor noises, pilot-air-traffic-control communication chatter, and emergency siren sounds. All of the sounds are independently controlled using the remote control.
Below is a connection block diagram showing how the active elements are connected to the PFx Brick.
The biggest challenge was integrating the Power Functions M-motor with bevel gear drive to operate the main rotor. This required rebuilding the upper rotor housing on the roof to allow for an axle to pass into the fuselage to the motor. The PFx Brick is mounted in the helicopter cockpit area. This gives the IR sensor visibility through cockpit windows. A Power Functions extension cable passes discretely through the floor and is used to power the PFx Brick with an external battery box. An M-Speaker brick is also mounted discretely on the bottom of the helicopter fuselage between the main landing gear. All of the lighting consists of tiny 2x3 mm surface mount white LEDs with tiny 36-gauge wires soldered to the LED pads. All the LED wiring is run to the nose of the helicopter where it connects to a pinLABduo light accessory board attached to the PFx Brick lighting dock connector.
This was a fun model to integrate the PFx Brick! Not only because of the challenging space constraints, but also because it showcases all of the PFx Brick's main capabilities in sophisticated motor control, lighting Fx and sound Fx. We worked hard to make the PFx Brick as small as possible so that models even as modest as this City Fire Helicopter can benefit from the magic of motion, lights, and sound!
Check out the video of this model in action in this follow up blog post!