Abstract:
A simulated toggle switch capable of being set and reset by remote means and being manually operated. Control signals are received by two on-board electronic drive circuit assemblies which cause two corresponding magnetic solenoids to drive two cams clockwise or counterclockwise, independently of each other. This, in turn, causes a bat handle to move to an uppermost position, a lowermost position, or to be centered. In addition, the position of the switch is remotely sensed.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is related to the following applications: &#34;Remotely Controlled Simulated Linear Circuit Breaker Assembly&#34; (Ser. No. 09/002,082) by Mark Arthur Callahan, Jeffrey Joseph Perloski, Christopher Joseph Murk and John Nicholas Merkle; &#34;Smart Test Equipment/ID Tagged Test Points&#34; (Ser. No. 09/002,084) by Jeffrey Joseph Perloski, Paul Joseph Hoshall and Lester Louis Smith; and &#34;Simulated Rotary Switch&#34; (Ser. No. 09/002,083) by Mark Arthur Callahan, Jeffrey Joseph Perloski and Richard Michael Quintavalle, each of which is filed concurrently herewith, commonly owned, and incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     When a student uses System Test Equipment (STE), the trainer must typically reset all toggle switches to a normal initial operating position on the remotely controlled equipment prior to allowing the trainee to begin his testing. Existing equipment allows detection of the positions of the toggle switches. However, they cannot automatically be set to the desired initial positions. The prior art does not contain an apparatus for automatically presetting the positions of the switches. 
     SUMMARY OF THE INVENTION 
     One object of the invention is to provide a toggle type switch that can be remotely set and reset in lieu of manual set and reset. 
     In addition, a second object of the invention is to provide a toggle type switch whose position can be remotely sensed. 
     Still a third object of the invention is to provide a toggle type switch which provides the same feel and appearance as an ordinary toggle type switch and can be manually operated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an assembly drawing of the remotely controlled toggle switch assembly. 
     FIG. 2 is a schematic of the toggle switch electronic drive circuit card assembly. 
     FIG. 3 is a detailed side view of the remotely controlled toggle switch assembly with part of the mounting bracket removed for clarity. 
     FIG. 4 is a detailed top view of the remotely controlled toggle switch assembly with part of the electronic drive circuit card assembly removed for clarity. 
     FIG. 5 illustrates a plurality of remotely controlled toggle switches in a maintenance system trainer. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The components of the remotely controlled toggle switch are described with reference to FIGS. 1, 3 and 4. The remotely controlled toggle switch&#39;s mounting bracket 1 provides the mounting frame for the assembly&#39;s components and also provides the mounting interface for the assembly via a threaded bushing 2, a lockwasher 3, and two nuts 4. The threaded bushing 2 also provides a pivot point 5 for the bat handle 7 via a first spring roll pin 6 which is pressed through the bushing 2 and handle pieces 7. At the end of the bat handle 7 is a second spring roll pin 8, which is used by two cams 9 to actuate the bat handle 7 to its up, center, and down positions. Two electronic drive circuit cards 10 are fastened with four screws 11a, lockwashers 11b, and flat washers 11c to ears 27 located on the top and bottom of the mounting bracket 1, which have four threaded inserts 28 pressed in. Two magnetic latching solenoids 12 are similarly fastened to the sidewalls of the mounting bracket 1 with two screws 13a and lockwashers 13b. Two spacers 15 between each solenoid 12 and the mounting bracket 1 provide for alignment of the solenoids 12 within the assembly. Two solenoid coil winding leads 29 from each solenoid 12 are soldered to plated through holes on their respective electronic drive circuit card assembly 10. A round shaft 16, which is held with cotter pins 17 on either side of the mounting bracket 1 is used to support and allow for the rotation of two spacer bushings 14, two cam assemblies 9, and a torsion spring 18. Two push rods 19, two front spring roll pins 20 and a rear spring roll pin 25 connect the solenoid plungers 21 to the cam assemblies 9. A threaded shaft 22 mounted with two screws 23a and lockwashers 23b provides structural support to the center of the mounting bracket 1. 
     The toggle switch operates as follows. With both latching solenoid plungers 21 retracted into their housings 12 as shown in FIGS. 3 and 4, their respective push rods 19 rotate each of the cam assemblies 9 on the shaft 16 to their rearmost positions (clockwise for the top push rod 19 and cam 9 and counterclockwise for the bottom push rod 19 and cam 9 as viewed with the bat handle 7 facing left). Rotation of the cams 9 to this position allows the actuating notches 24 in the cams 9 to engage the bat handle&#39;s 7 second spring roll pin 8 in a perpendicular orientation, resulting in the bat handle 7 being centered in its bushing 2. 
     With the bottom solenoid&#39;s plunger 21 retracted in its housing, when the top solenoid&#39;s plunger 21 is ejected from its housing, its associated cam 9 rotates counterclockwise on the shaft 16 (to the left as viewed with the bat handle 7 facing left). This enables the notch 24 in the top solenoid&#39;s 12 cam to press down on the bat handle&#39;s 7 spring roll pin 8, pushing the bat handle 7 to its uppermost position. 
     Conversely, with the top solenoid&#39;s plunger 21 retracted in its housing, when the bottom solenoid&#39;s plunger 21 is ejected from its housing, its associated cam 9 rotates clockwise on the shaft 16 (to the right as viewed with the bat handle 7 facing left). This enables the notch 24 in the bottom solenoid&#39;s 12 cam to press up on the bat handle&#39;s 7 spring roll pin 8, pushing the bat handle 7 to its lowermost position. The torsion spring 18 is used to preload both cams 9 by engaging the spring roll pin 20 that attaches each push rod 19 to each cam 9. 
     The two magnetic latching solenoids 12 operate the toggle switch in the following manner. When an electric current is applied through the solenoid 12 winding through its two input leads 29, the magnetic field of the latching solenoid 12 is increased or negated depending upon the direction and magnitude of the current flow. When the solenoid plunger 21 is fully seated in its housing 12 and a current is applied to the solenoid 12 winding that negates the solenoid&#39;s magnetic field, the force of the torsion spring mounted on the cam shaft is able to withdraw the plunger from the solenoid housing 12. In the opposite case, where the solenoid plunger 21 is extracted from the solenoid housing 12 and a current is applied to the solenoid 12 winding that increases the solenoid&#39;s magnetic field, the magnetic field of the solenoid overcomes the torsion spring&#39;s force and the plunger is magnetically pulled back into the solenoid 12 housing. 
     Mounted to the opposite side of each solenoid bracket is one of two identical electronic drive circuit card assemblies 10 that provide directional current flow to each of the solenoid 12 windings. Each of the two magnetic latching solenoids 12 is individually controlled by a electronic drive circuit card assembly 10. The schematic diagram for the electronic drive circuit card assembly 10 is shown in FIG. 2. 
     Operation of the electronic drive circuit card assembly 10 is as follows. When a TTL level voltage is applied to the gate of the lower left FET transistor (Q3), its drain-to-source impedance goes to a minimum value (typically less than 1 ohm). This condition effectively connects the 24 Volt return at plated through holes E3 and E4 to one lead of the solenoid 12 winding, which is soldered to a plated through hole on the electronic drive circuit card assembly 10 designated E12. The low impedance of FET transistor Q3 also biases the upper right PNP transistor (Q2) through resistors R3 and R4, turning it on, thus allowing current to flow through the emitter-to-collector junctions and into the opposite lead of the solenoid 12 winding, which is soldered at plated through hole E13. R3 and R4 are selected to bias Q2 into saturation whenever Q3 is turned on. 
     Reverse current flow through the solenoid 12 winding is obtained when the lower right FET transistor (Q4) is turned on. When a TTL level voltage is applied to the gate of the lower right FET transistor (Q4), its drain-to-source impedance goes to a minimum value (typically less than 1 ohm). This condition effectively grounds the lead of the solenoid 12 winding that is soldered at E13 (which was ungrounded with forward current flow). The low impedance also biases the upper left PNP transistor (Q1) through resistors R1 and R2, turning it on, thus allowing current to flow through the emitter-to-collector junctions and into the opposite lead of the solenoid winding 12, which is soldered at E12 (which was grounded with forward current flow), thereby allowing a reverse current flow through the solenoid 12 winding. R1 and R2 are selected to bias Q1 into saturation whenever Q4 is turned on. On Q1 and Q2, pin 1 is the base, pins 2 and 4 are the collectors, and pin 3 is the emitter. 
     The polysilicon fuse (F1) protects the circuit in the event both FET transistors are turned on at the same time. The value of F1 is rated at 0.5 amps and is selected to allow for one solenoid to pass but in the event that both FET transistors are turned on at the same time the fuse would open. The transient suppressor (VR1) is placed across the solenoid 12 winding to reduce back EMF transients whenever the solenoid 12 winding current is turned off. C1 is a 0.1 microfarad bypass capacitor. It presents a low impedance to high frequency noise on the power line and shunts the noise to ground. 
     Each solenoid&#39;s 12 push rod 19 position is sensed by means of a photo reflective sensor (U1) located on each electronic drive circuit card assembly 10. This sensor U1 is capable of transmitting a beam of light and then detecting if this light beam has been reflected off of a nearby surface. Each push rod 19 has a machined flat surface 26 that reflects the beam of light generated by the sensor U1 that is on the electronic drive circuit card assembly 10. This light beam is detected by the sensor U1 whenever the push rod 19 is extended from the solenoid 12, i.e., the solenoid&#39;s plunger 21 is in the &#34;out&#34; position. Conversely, no light is reflected when the push rod 19 is not extended; i.e., the solenoid&#39;s plunger 21 is in the &#34;in&#34; position. Monitoring of the sensor&#39;s U1 output for each solenoid 12 provides for remote detection of the position of the remotely controlled toggle switch. Resistors R5 and R6 bias the inputs of FET transistors Q3 and Q4 off in the absence of an input signal and provide for noise immunity, while resistors R7 and R8 bias the input and output circuits, respectively, of the optical sensor. 
     Eleven other plated through holes are contained on the electronic drive circuit card assembly 10. E1 and E2 provide connections for inputting +24 volt DC power. E3 and E4 provide the return path connection for +24 volt power. Similarly, E7 and E8 provide connections for +5 volt DC power and E5 and E6 provide the return path for +5 volt power. Plated through holes E9 and E10 provide solder connections for the TTL input signals that control FET transistors Q3 and Q4, respectively. E9 and E10 are the locations of a first and a second input for the electronic drive circuit card assembly. On FIG. 2, the labels &#34;IN&#34; and &#34;OUT&#34; refer to the plunger position. Plated through hole E11 provides a connection point to the output of photo sensor U1. 
     FIG. 5 shows a plurality of remotely controlled toggle switches that comprise a maintenance system trainer. The trainer would control the operation of all of the remotely controlled toggle switches from his/her station. The maintenance system trainer comprises a plurality of remotely controlled toggle switches 405. Each remotely controlled toggle switch 405 is connected and electrically coupled to a control means via signal carrying means 420. The control means is a computer 410 having software 415 resident therein. The software generates control voltage pulses, which control the operation of the remotely controlled toggle switches. This is accomplished when the control voltage pulses, along with 24 volt power and 24 volt and 5 volt power returns are transmitted to the electronic drive circuit card assembly of the simulated toggle switch as signals to inputs E1-E10 of the electronic drive circuit card assembly. 
     While the invention has been disclosed in this patent application by reference to the details of preferred embodiments of the invention, it is to be understood that the disclosure is intended in an illustrative, rather than in a limiting sense, as it is contemplated that modifications will readily occur to those skilled in the art, within the spirit of the invention and the scope of the appended claims.