A radio-controlled model (or RC model) is a model that is steerable with the use of radio control (RC). All types of model vehicles have had RC systems installed in them, including ground vehicles, boats, planes, helicopters and even submarines and scale railway locomotives.
History World War II saw increased development in radio control technology. The Luftwaffe used controllable winged bombs for targeting Allied ships. During the 1930s the Good brothers Bill and Walt pioneered vacuum tube based control units for RC hobby use. Their "Guff" radio controlled plane is on display at the National Aerospace museum. Ed Lorenze published a design in Model Airplane News that was built by many hobbyists. Later, after WW2, in the late 1940s to mid 1950 many other RC designs emerged and some were sold commercially, Berkeley's Super Aerotrol, was one such example. Superregenerative receivers were used to keep the size and power consuption low. Originally simple 'on-off' systems, these evolved to use complex systems of relays to control a rubber powered escapement's speed and direction. In another more sophisticated version developed by the Good brothers called TTPW, information was encoded by varying the signal's mark/space ratio (pulse proportional). Commercial versions of these systems quickly became available. The tuned reed system brought new sophistication, using metal reeds to resonate with the transmitted signal and operate one of a number of different relays. In the 1960s the availability of transistor-based equipment led to the rapid development of fully proportional servo-based "digital proportional" systems, achieved initially with discrete components, again driven largely by amateurs but resulting in commercial products. In the 1970s, integrated circuits made the electronics small, light and cheap enough for the 1960s-established multi-channel digital proportional systems to become much more widely available. In the 1990s miniaturised equipment became widely available, allowing radio control of the smallest models, and by the 2000s radio control was commonplace even for the control of inexpensive toys. At the same time the ingenuity of modellers has been sustained and the achievements of amateur modelers using new technologies has extended to such applications as gas-turbine powered aircraft, aerobatic helicopters and submarines. Before radio control, many models would use simple burning fuses or clockwork mechanisms to control flight or sailing times. Sometimes clockwork controllers would also control and vary direction or behaviour. Other methods included tethering to a central point (popular for model cars and hydroplanes), round the pole control for electric model aircraft and control lines (called u-control in the US) for internal combustion powered aircraft. The first general use of radio control systems in models started in the late 1940s with single-channel self-built equipment; commercial equipment came soon thereafter. Initially remote control systems used escapement, (often rubber driven) mechanical actuation in the model. Commercial sets often used ground standing transmitters, long whip antennas with separate ground poles and single vacuum tube receivers. The first kits had dual tubes for more selectivity. Such early systems were invariably super regenerative circuits, which meant that two controllers used in close proximity would interfere with one another. The requirement for heavy batteries to drive tubes also meant that model boat systems were more successful than model aircraft. The advent of transistors greatly reduced the battery requirements, since the current requirements at low voltage were greatly reduced and the high voltage battery was eliminated. Low cost systems employed a superregenerative transistor receiver sensitive to a specific audio tone modulation, the latter greatly reducing interference from 27 MHz Citizens' band radio communications on nearby frequencies. Use of an output transistor further increased reliability by eliminating the sensitive output relay, a device subject to both motor-induced vibration and stray dust contamination.
… excerpt ends here. Continue reading the full article.
