Variable high-current electrical load bank with rapid adjustment over a wide range of currents
First Claim
1. An adjustable high current electrical load comprising:
- a frame;
first and second electrically conducting means, said first conducting means having a first surface and said second conducting means having a second surface facing said first surface, said first conducting means being fixedly mounted on said frame;
first spring means, said second conducting means being mechanically connected to said frame through said first spring means;
at least one pile of elements made substantially of carbon material, which pile being disposed between said first and second surfaces of the first and second conducting means, said at least one pile having a first and a second end facing respectively said first and second surfaces and having an electrical resistance between its first and second ends which varies with pressure applied on said at least one pile through its first and second ends, said first and second conducting means being mounted with respect to each other for applying substantially no pressure on said at least one pile during a non-operating state of said adjustable electrical load;
means associated with said second conducting means for applying pressure on said at least one pile through said second conducting means, said at least one pile being pressed between said first and second surfaces when said pressure applying means apply pressure thereon;
insulating means for preventing short-circuit between the first and second conducting means through the frame and/or the pressure applying means;
said pressure applying means comprising second spring means for producing, when said pressure applying means are operated, a force acting on said second conducting means against a force produced by the first spring means for applying pressure on said at least one pile disposed between said first and second surfaces of the first and second conducting means;
said pressure applying means also comprising means for continuing to apply pressure on said at least one pile through the second conducting means after said second spring means are inhibited or completely compressed up to a relatively high pressure;
whereby, in operation, an accurate adjustment within a range of light pressures, starting from a substantially zero pressure, applied on said at least one pile is enabled due to the reverse forces produced by said first and second spring means for enabling accurate adjustment of said electrical resistance of said at least one pile within a range of resistive values given by said range of light pressures, so as to enable to accurately adjust within said range of resistive values an electrical resistance of a series-circuit formed by the first conducting means, said at least one pile, and the second conducting means;
and whereby, in operation, the pressure applied on said at least one pile can be accurately varied within a range extending from said substantially zero pressure to said relatively high pressure so as to enable an accurate adjustment of the electrical resistance of said at least one pile within a wide range, for thereby accurately varying within this wide range the electrical resistance of said series circuit.
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Accused Products
Abstract
An adjustable electrical load bank which comprises an upper and lower horizontal, electrically conducting plates mounted parallel to each other on a frame and both electrically insulated from this frame. The lower plate is fixedly mounted on the frame while the upper plate is movably connected thereto through four spring devices. Three vertical piles of disk-shaped carbon elements are disposed between the two horizontal plates and each have an electrical resistance between their respective upper and lower ends which varies with pressure applied thereon. An upper and lower pistons separated by an helicoidal spring are disposed in a vertical cylinder mounted on the frame. The upper piston is associated with a manually operated cam while the lower piston is fixedly connected to the upper plate. Upon operation of the cam, the helicoidal spring produces a force acting against a force generated by the four spring devices for applying pressure on the piles. An accurate adjustment within a range of light pressures on the piles is therefore enabled due to these reverse forces for thereby allowing to give to the pile resistances corresponding values. When the helicoidal spring is completely compressed, the cam can still be operated to apply relatively high pressures on the piles to vary their resistances accordingly. The load bank is particularly suitable for use in wide current range battery testers.
4 Citations
24 Claims
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1. An adjustable high current electrical load comprising:
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a frame; first and second electrically conducting means, said first conducting means having a first surface and said second conducting means having a second surface facing said first surface, said first conducting means being fixedly mounted on said frame; first spring means, said second conducting means being mechanically connected to said frame through said first spring means; at least one pile of elements made substantially of carbon material, which pile being disposed between said first and second surfaces of the first and second conducting means, said at least one pile having a first and a second end facing respectively said first and second surfaces and having an electrical resistance between its first and second ends which varies with pressure applied on said at least one pile through its first and second ends, said first and second conducting means being mounted with respect to each other for applying substantially no pressure on said at least one pile during a non-operating state of said adjustable electrical load; means associated with said second conducting means for applying pressure on said at least one pile through said second conducting means, said at least one pile being pressed between said first and second surfaces when said pressure applying means apply pressure thereon; insulating means for preventing short-circuit between the first and second conducting means through the frame and/or the pressure applying means; said pressure applying means comprising second spring means for producing, when said pressure applying means are operated, a force acting on said second conducting means against a force produced by the first spring means for applying pressure on said at least one pile disposed between said first and second surfaces of the first and second conducting means; said pressure applying means also comprising means for continuing to apply pressure on said at least one pile through the second conducting means after said second spring means are inhibited or completely compressed up to a relatively high pressure; whereby, in operation, an accurate adjustment within a range of light pressures, starting from a substantially zero pressure, applied on said at least one pile is enabled due to the reverse forces produced by said first and second spring means for enabling accurate adjustment of said electrical resistance of said at least one pile within a range of resistive values given by said range of light pressures, so as to enable to accurately adjust within said range of resistive values an electrical resistance of a series-circuit formed by the first conducting means, said at least one pile, and the second conducting means; and whereby, in operation, the pressure applied on said at least one pile can be accurately varied within a range extending from said substantially zero pressure to said relatively high pressure so as to enable an accurate adjustment of the electrical resistance of said at least one pile within a wide range, for thereby accurately varying within this wide range the electrical resistance of said series circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification