Typically, electric closers are included in a simple electrical circuit consisting of a power source for an electric igniter (detonator) and an electric switch. Sometimes, if the sensitive element works to break the circuit, the circuit is slightly complicated, a transistor, a capacitor and several resistances appear.
Homemade push-button electric locks, design and installation features, simple barometric closure.
Electronic contactors can contain very complex circuits, but these circuits relate to the device of the contactor and usually do not affect the circuit of the contactor in the circuit with an electric igniter. Roughly electric closers can be divided into the following groups.
Mechanical, responsive to mechanical influences: pressing on them or near them, removing the load (unloading), pulling the thread, plate, etc., shifting the elements of the contactor, vibrations, changing the position of the contactor relative to the stationary state, magnetic poles of the earth, etc..
Electronic, responding to changes in the electromagnetic parameters of the medium (capacitive, inductive, radio fuses), or equipped with decoding devices and reacting not to any effect, but to a certain sequence of signals, or to a certain signal frequency.
An intermediate position may be occupied by the simplest optical and acoustic contactors. Fuses are often inserted into the circuit of the electric closures. And switches that turn on or remove the electric igniter after installing and checking the circuit. To reduce the risk of self-explosion. Even more effective are timers that include ignitors (detonators) in the circuit a certain time after the installation of ammunition. In the figure below: ED – electric detonator, EZ – electric closure, Rb – high resistance, Rm – low resistance, CR – electrical circuit for breaking.
Features of the design and installation of push-button electric locks.
During installation, it is advisable to place push-button electric closures (especially buried in the ground) in a plastic bag to prevent dirt and moisture from getting inside. As push-pull contactors, standard push-button switches can be used. Such switches and similar home-made ones, it is good to provide a cover, it is even better to place two between two boards (slazes), and between the plates three – four parallel connected switches.
In all these cases, the area controlled by the switch will increase. For the same purpose, you can clamp the switch between two plates of flexible plastic. Pushbutton switches are divided into switches that turn on when pressed, and then hold the circuit, and switches that hold the circuit while they are pressed (like a bell). If possible, especially when using low-power supplies and improvised ignitors, it is better to give preference to the first.
Homemade push-pull electric locks.
Homemade push-button electric closures can repeat factory push-buttons, and consist of two contacts, which the spring does not allow to connect. In another case, the switch may consist of two conductive plates, which are located close to each other, and when pressed, they are connected. A classic is a matchbox with contacts inside, two plywood, cardboard boxes, flexible boards, etc. with metal plates.
Or simply metal plates laid at a short distance from each other with separating dielectric inserts at the edges, which do not allow for the time being to be closed. As contacts, instead of metal plates, you can use wire, it can be laid out in the form of a spiral or in the form of a zigzag. The last option is more economical.
But it is necessary to ensure that when connecting the plates, the wires are connected twice on each bend of the zigzag. If you imagine the wire as a graph of a sine wave, then both graphs should differ by half the period. A very good contactor can be obtained from a solid plate or plywood, (if a hard floor, then it is not needed), a piece of polymer film, two pieces of foil and stationery buttons.
Between two pieces of foil, a film is laid and this “layer cake” is laid on the buttons laid with the tip up on the plate. When the buttons advance, a film is pierced with both sheets of foil acting as contacts, a closure occurs. At the end of the figure above, the sequence of manufacturing the contactor from two metal plates and a paper tape is shown..
There are hydraulic electric closures that respond to soil compression, they are a rubber pad filled with water or a heating pad (without air), a tube connected to the syringe comes out of the pad, and when the piston moves, the contacts close.
The simplest barometric closure.
Even more sensitive is the air chamber in the duct. With increasing pressure, the volume of the air chamber decreases, the electrolyte solution (such as sodium chloride) rises and closes the contacts. The principle inherent in the idea of an air chamber in a duct can be used in a simple barometric closure. In this case, the closure should look like a bird bowl.
The simplest barometric closure can also be made by pulling a rubber film (from a balloon or a condom) onto the neck of the can. When bending inward, the film closes the contacts. A barometric closure is best made from a standard barometer (like a clock). A mine with a barometric contact can be installed on a submarine, even set it to a certain depth. Or on a plane, setting it to a certain height.