A simple circuit breaker for a car.

When the car is parked for a long time, many motorists want to disconnect the battery from the on-board network, and in order not to constantly open the terminals, they independently install all kinds of mechanical switches in the engine compartment, because such switches are not provided in serial cars.

The contacts of mechanical switches must be designed to carry a current of several hundred amperes and have a very low contact resistance, therefore the use of conventional mains switches or toggle switches is not acceptable in this situation. For these purposes, there are special switches for the mass of the car, for example, VK-318, or in some articles that come across on the sites, the device for remote switching off of the RAD-1 mass is mentioned, although we could not find information on the RAD on the Internet. (Maybe, of course, we were looking badly and in the wrong place, but nevertheless ...).

The circuit that we want to offer has no mechanical contacts, and its main advantage is that this disconnect switch can be controlled remotely using a small toggle switch or a button with fixed positions installed in any place convenient for you. It can be installed in the passenger compartment, and in order to turn off the ground, it will not be necessary to open the hood lid.

This diagram, as it was a long time ago, was published in one of the radio engineering magazines, so we will not reinvent the wheel and redraw it in our own way, it is quite informative and intelligible, so we post you a scan of the circuit diagram in the original as it is without changes.

The figure shows that the high-power thyristor and diode are installed on an aluminum corner with the indicated dimensions. On the vertical side (according to the figure) there is a hole through which it is attached in the engine compartment to the car body not very far from the battery.

The thyristor works like a key; when the toggle switch is on, it will be open. But there is one “but” ... As you know, a thyristor can pass current only in one direction (from the anode to the cathode), and in order for the battery to receive recharging from the generator in parallel with the thyristor, a diode with opposite polarity is installed.

The fastening of the corner to the car body must have good electrical contact, and the wire connecting the thyristor with the tip must have a fairly impressive cross-section, you can use the one that connects the negative terminal of the battery to the car body, otherwise no critical requirements are imposed. Some craftsmen advise to put the device in a metal box and paint it in the color of the car body.

The parameters of some powerful thyristors are shown in the following image, to enlarge which click on the picture.

Manufacturers place the batteries either in the luggage compartment, under the rear seat, or in another secluded area that is difficult to access. If a fire breaks out in the wiring of a vehicle, it can be very difficult to save the car, since the terminal cannot be quickly reset. The main switch can easily solve the problem.

With its help, you can de-energize instantly. In addition, the battery disconnect switch is an excellent opportunity to protect the vehicle from theft, because the intelligently hidden switch button and the lock on the hood, which prevents intruders from accessing the battery, are reliable protection. A 4 ampere bimetallic fuse installed in parallel in the electrical circuit will enable the car alarm to work even when the mass is off.

When choosing, it is recommended to pay attention to the KamAZ power switch, which is easy to control directly from the cab of the car - remotely. It works perfectly at 12 volts, and in the old days, anti-theft systems of cars were equipped with KAMAZ ground switches. The principle of operation is immediate power off.

You can install the masses yourself. For this, in addition to the device itself, you will need a wire with crimp connectors having a cross section of 35 mm, thermal

glue in the gun, lead terminal and sealing rubber.

Remove the negative terminal from the battery and remove the old ground wire. Find an inconspicuous corner in the cabin where you should install a power switch and make a small hole for wiring, covering the metal with an anti-corrosion compound and sealing with rubber for mirrors. You need to insert a wire into the hole, and then seal it with glue. isolate. This will prevent the formation of a short circuit in the circuit. It needs to be stretched along the body. The disconnect switch must be securely fixed.

Next, you need to mount a low-current fuse and connect the case to the negative terminal of the battery, bypassing the ground switch, so that the alarm, computer and audio device continue to work when the circuit is de-energized. If a powerful voltage turns on in the circuit or a short circuit occurs, the fuse will be damaged and the circuit will be de-energized.

It remains to complete the work that will provide energy to the central locking, light and standard For this, you need to connect an additional relay to the electrical circuit. With its help, during the operation of these devices, the main switch will be bypassed. Of course, this scheme is not easy for an inexperienced person in an auto electrician, so the advice of a specialist will be very useful here.

Having installed the device, always have spare bimetallic fuses in stock, forgetting to turn off the starter once, you can easily burn them out. Secure the wires with two serrated washers, and regularly coat the lead terminal on the battery with lithol.

Instructions

The easiest way is to remove the wire from the negative terminal of the battery. Take a wrench corresponding to the nut on the terminal, loosen the nut and, having removed the wire, fix it in some niche, excluding accidental contact with the negative terminal of the battery.

It is more convenient to install a disconnect switch. There are various modifications on sale for every taste. Connect it to the negative wire between the battery and the car body, ensuring good contact. Disconnecting the ground, press one button, before starting the engine, press the other, closing the circuit.

In order not to get out of the car and open the hood by turning off and turning on the ground, run the wires from the negative terminal into the passenger compartment. Place the toggle switch in a place convenient for you. Such a switch may only be known to you and at the same time play the role of a "secret" - an anti-theft device. Without knowing the location of the toggle switch, an outsider will not be able to start the engine.

Modern cars, stuffed, as they say, with "brains" are not indifferent to the power outage of the electrical on-board network. Many motorists generally consider turning off the mass on such cars completely unnecessary. Their protection system will not allow a short circuit to arise, from which fires still occur on old domestic cars. The leader of such fires is "Zhiguli" ("penny").

However, if you leave the car for a long time, then it will be useful to turn off the mass on the "foreign car". In order not to de-energize all electronics and signaling with a siren, connect a 3-5 A fuse in parallel with the disconnector. The current passing through this fuse will be sufficient for the operation of the electronics and signaling. And in the event of a serious short circuit, the fuse will simply blow.

Experienced drivers need not be told about the benefits of a disconnect switch. This device protects the battery from discharge during long-term parking, and also, if properly installed, acts as a simple anti-theft system.

It is not difficult to figure out how to put the disconnect switch correctly. But if you are not particularly good at electrical circuits, it is better to leave this job to professionals or get preliminary advice from them.

How to install a battery master switch to a car?

The disconnect switch is mounted next to the battery or directly on it and has the function of preventing the leakage of electrical charge from the battery. If there is also a fuse on the switch, the electrical system of the car is not completely de-energized. In this case, the alarm siren, central locking, on-board computer and radio tape recorder remain energized. But if an intruder takes up the job, his attempt to start the engine will most likely end in failure, because the fuse breaks down from the starting current of the starter and the car's system is de-energized.

Therefore, if you have already started looking for how to install a power switch, you should contact a specialized store, where you can find several suitable options. The simplest is a terminal with a built-in switch. But here it is important that it can withstand the load coming from your battery. Failure to do so may result in breakdown or even fire.

If you have decided on the model of the disconnect switch, experts will best tell you how to install it. To do this, disconnect the terminal from the "ground" and the positive terminal of the battery. The next step is to disconnect the terminal from the wire. Just keep it in case you no longer need the disconnect switch in the future.

Check the condition of the battery, electrolyte level, and service it. The battery disconnect switch should be connected to the negative terminal of the battery and securely fastened. Also connect the mains wire to the positive terminal.

The ground wire is connected to the switch in accordance with the instructions supplied with the kit. Turn off the device and try to start the engine. If everything is working properly, after turning off the ignition, turn on the main switch. If you were able to how to connect the remote master switch, all systems in the car will be powered when the key is turned, but trying to start the engine will blow the fuse.

How to connect the main switch on a car with a modern electrical system?

In many new models, an unscheduled disconnection of the battery can lead not only to zeroing the computer, radio and clock, but also have a negative impact on the quality of engine starting. Therefore, if you are not fluent in the science of electrical engineering, it is better to outsource this work to specialists or order revision from a dealer.

But even in such a situation, you can find a way out. To do this, it is enough to install a cheap source of electricity, which will allow you to keep security codes and important information in the device's memory. In extreme cases, the battery can not be disconnected, using small clips for this, which will act as improvised fuses, and save the necessary information in the device's memory in the event of a short circuit.

You will find out the required minimum of information about the battery disconnect switch right now. Electricity is supplied to every yacht, boat or boat using a rechargeable battery, and often more than one. To switch between them, use a special device. The switch simplifies the selection of the power supply. If necessary, you can also select the combined (shared) battery mode.

You may also need toggle switches, relays, and switches to help protect your boat electronics from short circuits and provide additional contact reliability.

Power switch - price and other features of the device

With its help, the yacht, boat or boat is disconnected from the electricity supply in one motion. Thus, it is possible to protect the electrical equipment of the vessel from short circuits during repair work or parking. Plus the battery is discharged much more slowly. With the built-in voltmeter or ammeter, it is convenient to monitor the battery consumption.

The most common types:

• Mechanical with manual control;
• Automatic - the action takes place simultaneously with the engine start;
• Electromagnetic or electric - activated by a special button or toggle switch;
• Electronic - control through a special board;

The most convenient is the model with a button on the panel or control panel. If the device is not included in the starting configuration of the vessel, the issue is resolved by purchasing a remote device. The device itself is inexpensive, and its price is determined primarily by the characteristics of a small vessel.

In the online store "1000 sizes" with the help of experienced consultants, you will quickly find your way around a wide range of switches and select a suitable option for all parameters. All types of electrical equipment are protected by the manufacturer's warranty and are carefully checked before shipment.