FR2726112A1 - Remote door-opening electronic device operating at variable frequency - Google Patents

Abstract

The device includes a timer (1) and a housing (2) containing electronic circuitry. The circuitry includes a step-down transformer (3) receiving the 220 V AC supply during selected hours which are set by the timer. The 12 V output is fed to a 556 integrated-circuit dual timer (4) which generates pulses about 5 seconds wide to a relay (5). The pulse interval is adjustable by a potentiometer (8) between 45 seconds and 4 minutes. An LED (7) indicates when the relay contact is closed and the two output wires of 2 mm dia. "banana plugs" are connected together.

Description

 The present invention relates to an electronic device for a remote door opener with an adjustable duration (by timer) and variable frequency (by potentiometer), without any manual intervention.

The opening of these doors is traditionally done by electrical or electronic means (Digicode for example), which would be unusable under certain conditions.

Some door openers have a key but still operate an electrical (or electronic) system that would not be possible to use.

The device according to the invention overcomes this drawback.

It in fact comprises a timer regulating the time slots (not claimed here) and an electronic unit, object of the invention, providing a "dry contact" connected to the two door opening wires (for example the intercom of the apartment). A transformer supplies power to the integrated circuit; the latter (double timer 556) coupled to the resistors, diodes and capacitors provided generates a pulse at variable frequencies which brings the two output wires into contact via a relay; this contact is finally sent (via the intercom) to the door of the building which allows it to open without manual action. In addition, an LED has been added to indicate the times when the contact is present.

According to particular embodiments:
-The values of resistors, diodes and capacitors are adjusted to obtain
a pulse lasting 5s and a repetition frequency of 45s at 4mn.

 Other values can be chosen according to the need.

-The electronic unit and the timer are either separate or included in a
same box.

-As an example, the timer used is mechanical to reduce the cost and
increase reliability; other type of (electronic) timer could be
chosen
-The 220V / 12V transformer was chosen to minimize the ratio
cost / power required; other transformers could be used.

- The 556 double timer used is the simplest way to perform the
generation of an output pulse
The accompanying drawings illustrate the invention:
Plate 1/2 Overview of the door opener: block diagram
Plate 2/2: Electronic diagram of the card
With reference to these drawings, the device comprises: a transformer (220V / 12V) (3) which is responsible for supplying power to all the electronics; being connected to the timer 220V (1), it will only power the circuit during the time slots chosen on it. A fuse (6) has been added to prevent an over-voltage at the input damaging the electronics.

A double timer integrated circuit 556 (4) managing the pulses with a duration of 5s (approximately) and composed of two "half 555". A variable resistor with potentiometer (8) makes it possible to modify the repetition frequencies of the contact pulse (from 30 s to 4 min).

The output of the 556 is connected to a 12V relay (5) ensuring contact with the 2 output wires of the device. These 2 wires are connected to two "banana plugs" with a diameter of 2mm. The different diameter of conventional 220V outputs has been deliberately chosen in order to avoid any short circuit by connecting a standard 220V socket. An led (7) output indicator allows to indicate the moments when the contact occurs.

Finally, a box (2) contains all of the electronics, wired according to plate 2/2.

This electronics is divided into three main parts which we will detail below:
* food
* the integrated circuit
* the output electronics with its relay and the indicator LED
Note: The numbers and letters between () represent the components of the electronic circuit; those between [] indicate the input / output terminals of these components. Some letters have been added to facilitate understanding of Plate 2/2.

Food includes:
* a 220/12 V (3 VA) transformer (TI)
* a 300 mA fuse (F1)
* 1A diode bridge (D1)
* a 7812 regulator (U1) where VI and VO symbolize the input voltages,
output respectively
* a capacitor (C1) of 470, uF
This first set (at the top of the 2/2 board) provides a regulated 12V power supply; VCC represents 12V; the JP1 socket symbolizes the 220 V input of the timer.

The second set (in the center of board 2/2) is organized around the integrated circuit "double timer" 556 (U2A and U2B: it is a "dual" 555) whose output [9] is looped on the trigger [ 6] with a capacitor (C4) of 47 nF, itself connected to 12V (VCC) via a resistor (R6) of 15 K. n operates as a 5s pulse generator taking into account the values of resistors and capacitors connected to [ 1 and 2]:
* resistance (R7) of 330 K
* 15 uF capacitor (C7)
In parallel with this assembly, the outputs [13], [12] and [8] of the other part of the 556 (U2B) are connected to a capacitor (C6) of 470 s1F and three resistors with values of 47 K (R8), 12 K (R4) and 470 K variable (R3). Using a potentiometer modifying the value of this last resistance, the repetition frequency of the pulse can vary between 30 s to 4 min (taking into account the aforementioned values ).

The CV outputs [3] and [11] (control voltage) of the 556 are connected to two capacitors (C3 and C5) of 100 nE
The outputs R (Reset) [4] and [10] are connected to 12 V (VCC). The [10] goes through a resistance R5 of 10 K.

The voltage outputs 12V and "ground" OV respectively [14] and [7] of the 556 are not shown on the board 2/2.

Finally, the output [5] of the 556 is connected, via a 15 K resistor (R2), to the third part of the circuit on the right of the 2/2 board composed of:
* the led (D2) with its resistance (R1) of 1 K
* the 12V relay (K1) connected to the 2N 2219 transistors (Q1) and to the diode
1N 4007 (D3)
* the two output wires with the 0.1 uF capacitor (C2).

The JP2 socket represents the two output wires which are brought into contact by the entire system described above.

By way of nonlimiting example, the case will have dimensions of 5 cm in height, 7 cm in width and 11 cm in length. The electronic card will be 7 cm wide and 10 cm long.

The device according to the invention is intended for the opening of digital code doors (for example), without any human or manual intervention. It is more particularly used by people of the Israelite faith on religious holidays.

Claims (6)

1) Device for opening doors remotely without manual intervention of an adjustable duration and variable frequency characterized in that it comprises an electronic unit (2) with a power supply (3) supplying the voltage to the integrated circuit (4) generating a pulse to a relay (5) making contact between the two output wires. 2) Device according to claim 1 characterized in that it has a double timer 556 operating as a pulse generator of variable duration at adjustable frequencies 3) Device according to claim 1 or claim 2 characterized in that it has an adjustable resistance by potentiometer to vary the pulse frequency (or contact) 4) Device according to claim 1 or claim 2 characterized in that it has a witness LED indicating that contact is made 5) Device according to claim 1 characterized by the use of a different diameter for the output contact to avoid any short circuit with conventional 220V plugs 6) Device according to any one of the preceding claims characterized by the use of a timer providing general power to the electronic unit for adjustable and variable periods and this without limitation on the time slots