US3525028A - Electronic control for the movement of large objects,particularly movable blackboards - Google Patents

Electronic control for the movement of large objects,particularly movable blackboards Download PDF

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Publication number
US3525028A
US3525028A US631252A US3525028DA US3525028A US 3525028 A US3525028 A US 3525028A US 631252 A US631252 A US 631252A US 3525028D A US3525028D A US 3525028DA US 3525028 A US3525028 A US 3525028A
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Prior art keywords
movement
objects
electronic control
contact
transistor
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US631252A
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Walter Ruoss
Hans Jenny
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Walter Ruoss
Hans Jenny
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Priority to CH552166A priority Critical patent/CH455189A/en
Application filed by Walter Ruoss, Hans Jenny filed Critical Walter Ruoss
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    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03KPULSE TECHNIQUE
    • H03K17/00Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/94Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
    • H03K17/96Touch switches
    • H03K17/9645Resistive touch switches
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02PCONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P23/00Arrangements or methods for the control of AC motors characterised by a control method other than vector control
    • H02P23/24Controlling the direction, e.g. clockwise or counterclockwise
    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03KPULSE TECHNIQUE
    • H03K17/00Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/51Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
    • H03K17/56Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
    • H03K17/60Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being bipolar transistors
    • H03K17/64Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being bipolar transistors having inductive loads

Description

FIG.1
w, nu o ss- ETAL 3,525,028 ELECTRONIC CONTROL FOR THE MOVEMENT 0F LARGE OBJECTS PARTICULARLY MOVABLE BLACKBOARDS Filed Aprll 17, 1967 2 Sheets-Sheet l INVENTORS= Walter E6105:
and flaws \Efln y m/kA'IToRNEY:
W. RUOSS ET AL ELECTRONIC CONTROL FOR THE MOVEMENT. OF LARGE Aug. 18, 1910 OBJECTS, PARTICULARLY MOVABLE BLACKBOARDS Filed April 17. 1967 2 Sheets-Sheet 2 w GE INVENTORS S Y MN u. N RE J m (a U N "in W H United States Patent US. Cl. 318446 1 Claim ABSTRACT OF THE DISCLOSURE An electronic control system for large objects which uses linear contact units instead of spot contacts. The contact unit consists of a high-grade insulator carrying two conductors consisting of non-oxidizable metal bands and corresponds to the length of the object to be moved. Contact can be established by bridging the two conductors with a finger at any desired spot, whereby due to the resistance inherent in the human skin, but slight current flow is elfected. The latter then is amplified and actuates a relay which effects a switching operation. The device is particularly useful, but not limited, to the actuation of movable blackboards.
Objects of large dimensions, controlled electrically, such as extensive rotating machines or large vertically movable blackboards, frequently require electrical contacts for activation or inactivation which must be located at different points of their frames. These points often are remote from each other.
It is the object of the invention to devise electronic controls for such large objects which has as its salient feature the installation of contact means which are not point contacts but linear units. These are disposed within the area of the object in the form of a strip or bar which consists of a high-grade insulator carrier whereon two non-oxidizing metal wires or bands are disposed. When a human finger is laid on any desirable point of the unit, the metal bands are interconnected. Hence, the current flowing in the contact wires or bands, due to the resistance inherent in the human skin, is very slight but, by means of a temperature-compensated amplifier, actuates a relay which effects a switching operation which ceases upon the removal of the finger.
The invention will now be further explained with reference to the accompanying drawings. However, it should be understood that these are given merely by way of explanation, and not of limitation, and that it is intended to cover all embodiments of the invention which are within the scope and the spirit of the invention as hereinafter claimed.
In the drawings,
FIG. 1 is a perspective of a contact unit;
FIG. 2 is a section through a contact unit;
FIG. 3 is a circuit diagram for a contact unit;
FIG. 4 is a front elevation of a blackboard provided with a contact unit according to the invention;
FIG. 5 is a horizontal projection of the blackboard shown in FIG. 4; and
FIG. 6 is an elevation taken along lines II of FIG. 5.
Referring now to these drawings, the contact unit shown in FIGS. 1 and 2 consists of a high-grade insulating material 1 as carrier on which two non-oxidizable metal bars or strips 2, 2a, and two like metal bands 3, 3a are disposed. The connecting wires are designated as 5.
FIG. 3 is an electronic circuit diagram wherein a direct current of, e.g., 22 volts is introduced at 6. The slight "ice current flowing, when finger '4 touches the contact unit 2, 2a or 3, 3a, is amplified approximately 200 times in transistor 9, and serves to control transistor 12; the latter controls relay 14 which is provided with high-voltage current contacts and controls the motor. Resistance 8 is to limit the current flow in case of a short circuit in the contact unit. NTC resistances 7 and 10 serve to adapt current and voltage and simultaneously as temperature compensators. Resistance 11 also serves to adapt current and voltage. The diode 13 protects the switching transistor 12. The entire assembly is hooked up to the contact unit by the connecting wires 5.
While it is evident that the contact unit as described lends itself to a multitude of applications, its utilization on blackboards with vertically movable panels has been found particularly gratifying. Such blackboards are widely used and frequently have a plurality of panels. To date, the movement of these panels is controlled by motors which are actuated by push button contacts. These are installed in the front or at the side of the board and actuate a mechanical movement system, i.e., they operate one of the switches in the system. However, even with blackboards of comparatively small length, a confusing amount of push buttons is present from which the lecturer must choose the correct one. With a blackboard of, e.g., 4 m. length, and there are in use today those of twice that size, one button each is required for the upward and the down ward movement and one for stopping. If push button groups were installed at a distance of one meter, five such groups would be required and 10 for two panels disposed one behind the other. It follows that the lecturer would have to be concerned with the operation of the blackboard to such an extent that his presentation would suffer therefrom. Hence, the electronic control system according to the invention provides an ideal solution.
FIGS. 4-6 illustrate the application of the system according to the invention to a vertically movable blackboard. These illustrations are schematics and omit the customary accessories, such as motors, etc.
Panel 17 moves between the guide posts 15 and 16. The contact bar 18 has the contact units 2, 2a and 3, 3a, and the broken-line (FIG. 4) rectangular oblong denotes the electronic control. The latter is actuated as soon as one of the contact units is touched by a human finger at any point. This immediately activates the motor 20, by means of the electronic control as explained below, and the panel moves as desired. The current supply is interrupted when the finger is removed from the contact bar, and the motor stops so that the panel comes to rest in the desired position.
As previously indicated, the circuit is at 6 connected to a direct current supply of for instance 22 volts. The resistors 7, 8 and 11 serve for stabilizing the operation of the transistor 9. The resistor 10 is the working resistor of the transistor 9. The NTC resistors 7 and 10, as indicated, serve to compensate for temperature variations.
The diode 13 eliminates the cutoff voltage peak on the relay 14. The high voltage contacts 22 of the relay 14 serve for closing a switch 19 that has contacts 23. The driving motor is indicated 20. A three-phase system 21 having a zero conductor forms the power supply for it.
The operation is as follows:
To lower the blackboard 17, the operator will place his finger 4 across the upper rails 2 and 2a. As these rails extend over the entire length of the blackboard, the operator does not change his actual position. By connecting the two rails with the finger the skin resistance of which is up to 5 megohms, a very small current flows in the transistor 9. The latter operates in collector arrangement and therefore causes a current amplification. This current appears primarily as a base current on the switching transistor 12 and is suflicient to saturate the transistor 12 to such an extent that it becomes so low-resistant in its emitter-collector circuit that practically the entire supply voltage lies on the relay 14, causing the latter to switch. Across the high-voltage contacts 22 of the relay 14 a voltage of for instance 220 volts is connected to the coil of the switch 19 which closes the contacts 23 to energize the motor 20 by connecting it with the three-phase power supply system 21 that has a voltage of 380 volts. The rotation of the motor may be transferred into a blackboard movement by any known means, for instance a chain drive and a gear (not shown). By lifting the finger 4 off the rails the current flow and thus the movement of the blackboard are interrupted. For raising the blackboard, the operation just described holds true in identical manner for the parts indexed with b on the reference numerals, the finger 4 being used to connect the rails 3 and 3a (FIG. 1) and to cause the motor 20 to reverse its sense of rotation. Thus a separate circuit is used for each direction of the blackboard.
Any motor may be used in this connection; the embodiment shows an alternating current motor of known type. Also the switch 19 may be of any suitable conventional known type.
The circuit described has the advantage of reacting neither to capacitive nor to inductive interferences, and operates at extremely low currents.
It should be pointed out that the contact units, contact carriers, i.e., the entire system, need not be in a straight line but may be in any shape conforming to the device which it is to serve.
We claim as our invention:
1. A contact unit for the control of the movements of large objects which comprises a high-grade insulating carrier; at least two substantially parallel non-oxidizing metal strips disposed thereon; a low-voltage power supply connected to said metal strips; said metal strips being at a distance from each other which can be spanned by a human finger for small current flow; means for amplifying said current; and motor and switching means for actuating and stopping said movements; contact between said unit and said motor and switching means being accomplishedbylaying a finger across any point of said parallel metal strips; said low-voltage power supply being of a magnitude as to be innocuous to the human body and wherein said means for amplifying said power supply and said switching and motor means comprise 'a first amplifying transistor amplifier; a second control transistor connected in seriestherewith; a diode between said second transistor and one terminal of said power supply; and a relay between said second transistor and the said terminal of said power supply; one resistor connected at one end thereof to a point between said first and second transistors and with the other end thereof connected to said one terminal of said power supply, and another resistor connected between said first transistor and the other terminal of said power supply.
References Cited UNITED STATES PATENTS 2,576,929 12/1951 Ercolino 200-159 X 2,946,956 7/1960 Bradley 3281 3,020,528 2/1962 Swanson et a1. 340-235 3,056,907 10/1962 Costanzo 317-149 3,207,905 9/1965 Bray 250206 3,218,530 11/1965 Momberg et al. 3l8--478 X 3,255,380 6/1966 Atkins et a1 307-116 X ORIS L. RADER, Primary Examiner A. G. COLLINS, Assistant Examiner
US631252A 1966-04-15 1967-04-17 Electronic control for the movement of large objects,particularly movable blackboards Expired - Lifetime US3525028A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CH552166A CH455189A (en) 1966-04-15 1966-04-15 Wall panel with an electrical device for controlling an electric motor that performs its displacement movement

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US3525028A true US3525028A (en) 1970-08-18

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US631252A Expired - Lifetime US3525028A (en) 1966-04-15 1967-04-17 Electronic control for the movement of large objects,particularly movable blackboards

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US (1) US3525028A (en)
AT (1) AT283156B (en)
CH (1) CH455189A (en)
GB (1) GB1133182A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3651391A (en) * 1969-09-26 1972-03-21 Black & Decker Mfg Co Electronic switch arrangements
US3651389A (en) * 1968-11-09 1972-03-21 Nippon Denso Co Safety device for use with automatic automobile window regulator
US4132935A (en) * 1976-09-23 1979-01-02 Braun Aktiengesellschaft Phonograph turntable control system
US5396222A (en) * 1993-03-25 1995-03-07 United States Surgical Corporation Ergonomic machine actuator

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2576929A (en) * 1949-09-02 1951-12-04 Ercolino Michael Direction finding device
US2946956A (en) * 1958-08-28 1960-07-26 United Shoe Machinery Corp Body conductivity operated controls for electric devices
US3020528A (en) * 1959-04-20 1962-02-06 Jr Caleb V Swanson Toilet training apparatus
US3056907A (en) * 1958-10-16 1962-10-02 Hubbell Inc Harvey Touch controlled circuit
US3207905A (en) * 1961-08-17 1965-09-21 Gen Electric Touch-sensitive optoelectonic circuits and indicators
US3218530A (en) * 1961-08-31 1965-11-16 Singer Mfg Co Motor speed control by space transmission of electromagnetic energy
US3255380A (en) * 1961-09-11 1966-06-07 Tung Sol Electric Inc Touch responsive circuit for control of a load

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2576929A (en) * 1949-09-02 1951-12-04 Ercolino Michael Direction finding device
US2946956A (en) * 1958-08-28 1960-07-26 United Shoe Machinery Corp Body conductivity operated controls for electric devices
US3056907A (en) * 1958-10-16 1962-10-02 Hubbell Inc Harvey Touch controlled circuit
US3020528A (en) * 1959-04-20 1962-02-06 Jr Caleb V Swanson Toilet training apparatus
US3207905A (en) * 1961-08-17 1965-09-21 Gen Electric Touch-sensitive optoelectonic circuits and indicators
US3218530A (en) * 1961-08-31 1965-11-16 Singer Mfg Co Motor speed control by space transmission of electromagnetic energy
US3255380A (en) * 1961-09-11 1966-06-07 Tung Sol Electric Inc Touch responsive circuit for control of a load

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3651389A (en) * 1968-11-09 1972-03-21 Nippon Denso Co Safety device for use with automatic automobile window regulator
US3651391A (en) * 1969-09-26 1972-03-21 Black & Decker Mfg Co Electronic switch arrangements
US4132935A (en) * 1976-09-23 1979-01-02 Braun Aktiengesellschaft Phonograph turntable control system
US4234836A (en) * 1976-09-23 1980-11-18 Braun Aktiengesellschaft Phonograph turntable control system
US5396222A (en) * 1993-03-25 1995-03-07 United States Surgical Corporation Ergonomic machine actuator

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Publication number Publication date
AT283156B (en) 1970-07-27
GB1133182A (en) 1968-11-13
CH455189A (en) 1968-04-30

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