Model railway power supply
AssigneeRosefair Electronics Limited
InventorMordecai Elias Cohen
Life of this patent
Estimating the term…
Abstract
A model railway or road vehicle installation in which vehicle-mounted electric drive motors are supplied through contact with track conductors, including a power supply providing an intrinsically safe a.c. component of such frequency and amplitude as to be capable of breaking down any contact inhibiting dielectric layer of dust, grease, metal oxide etc. on the track conductors, in addition to the normal d.c. component powering the vehicle. An automatic arrangement suppresses the a.c. component so long as good electrical contact is maintained so that the a.c. component is provided only when necessary. For facilitating slow speed operation, the d.c. supply is pulsed with a variable mark to space ratio dependent upon the desired vehicle speed thereby to maintain the torque output of the vehicle motor.
Claims13
In a power supply for a model vehicle installation wherein electrically powered model vehicles carrying their own respective drive motors are adapted to travel on a track drawing electrical power from trackside conductors through contactors on the vehicles, the improvement comprising normally suppressed means for supplying to said trackside conductors, in addition to the electrical power supplied to drive said vehicles, an alternating current component of such frequency and amplitude as to be capable of breaking down a contact-inhibiting dielectric layer formed between the vehicle contactors and the trackside conductors, said alternating current supply means becoming operable only in response to the detection of a build-up of the dielectric layer between said contactors and said conductors.
In a model railway installation including a railway track, a wayside conductor associated with said track, at least one model railway vehicle having an inboard electric drive motor adapted to be driven by electric power supplied from said wayside conductor to the motor through contactor means on the vehicle engaged with said wayside conductor the invention which comprises
- a. power supply means for supplying an electric current to the wayside conductor to drive the vehicle, said power supply means including a domestic alternating-current supply voltage, rectifier means for deriving from said supply voltage a rectified D.C. current, and multi-vibrator means for deriving a square wave signal from said rectified D.C. current for application to said conductor to drive said vehicle;
- b. speed control means for selectively controlling said electric current to control the speed of the vehicle along the track, said speed control means including selectively variable time constant means for varying the time constant of said multi-vibrator means to selectively vary the mark-to-space ratio of said square wave, thereby to vary the speed of the vehicle;
- and
- c. oscillator means for applying to said conductor an alternating signal having an amplitude and frequency capable of breaking down any contact-inhibiting dielectric layer formed between said conductors and the vehicle contactors.
An electrical power supply system for model railroads or the like of a type including a direct-current motor-driven vehicle having contact means which engage a stationary conductive surface through which the driving power is supplied, comprising
- a. means for supplying direct-current control current to said conductive surface for driving the vehicle;
- means for varying the level of the direct-current control current to control the operating speed of the vehicle;
- and
- c. oscillator means for modulating the direct-current control current with an alternating-current signal to supply alternating-current power to the conductive surface for removing by ionization a dielectric layer of impurities thereon.
An electrical power supply system for model railroads or the like of a type including a direct-current motor-driven vehicle having contact means which engage a stationary conductive surface through which the driving power is supplied, comprising
- a. means for supplying pulsating direct-current power having a square-wave waveform to said conductive surface for driving the vehicle;
- means for adjusting the mark-to-space ratio of the direct-current pulses of said current supply means to control the effective level of the current and, consequently, the operating speed of the vehicle;
- and
- c. oscillator means for modulating the direct current with an alternating-current signal to supply alternating-current power to the conductive surface for removing by ionization a dielectric layer of inpurities thereon.
An electrical power supply system for model railroads or the like of a type including a direct-current motor-driven vehicle having contact means which engage a stationary conductive surface through which the driving power is supplied, comprising
- a. means for supplying direct-current control current to said conductive surface for driving the vehicle;
- b. means for varying the level of the control current to control the operating speed of the vehicle;
- and
- c. oscillator means for modulating the control current with an alternating-current signal to supply alternating-current power to the conductive surface for removing by ionization a dielectric layer of impurities thereon, said oscillator means being normally suppressed and being operable to supply the alternating-current power only upon the detection of the layer of inpurities on said conductive surface.
An electrical power supply system for model railroads or the like of a type including a direct-current motor-driven vehicle having contact means which engage a stationary conductive surface through which the driving power is supplied, comprising
- a. means for supplying direct-current control current to said conductive surface for driving the vehicle;
- means for varying the level of the direct-current control current to control the operating speed of the vehicle;
- and
- oscillator means for modulating the control current with an alternating-current signal having a frequency on the order of at least 500 Hz and a peak voltage of at least 100 volts, thereby to supply alternating-current power to the conductive surface for removing by ionization a dielectric layer of impurities thereon.
In a power supply for a model vehicle installation wherein electrically powered model vehicles carrying their own respective drive motors are adapted to travel on a track drawing electrical power from trackside conductors through contactors on the vehicles, the improvement comprising means for supplying to said trackside conductors, in addition to the electrical power supplied to drive said vehicles, an alternating current component having a frequency on the order of at least 500 Hz and a peak voltage of at least 100 volts, thereby to break down any contact-inhibiting dielectric formed between the vehicle contactors and the trackside conductors.
A model railway installation, comprising a railway track;
- wayside conductor means associated with said track;
- at least one model railway vehicle having an inboard electric drive motor adapted to be driven by electric power supplied from said wayside conductor means to the motor through contactors on the vehicle engaged with said wayside conductor means;
- a power supply unit coupled to said wayside conductor means, said power supply unit including means for supplying an electric current to the conductor means to drive the vehicle;
- speed control means for selectively controlling said electric current to control the speed of said vehicle along the track;
- and oscillator means for applying to said conductor means an alternating signal having a peak amplitude of at least 100 volts and a frequency on the order of at least 500 Hz, thereby to break down any contact-inhibiting dielectric formed between said conductor means and the vehicle contactors.
Dependencies are inferred from the claim text.