Autostart will help to significantly facilitate everyday activities, you can do it yourself without any problems. And the most elementary option is to use a simple and cheap car alarm. But this is ideal only if the control needs to be performed in a small radius. If there is a large distance between the receiver and the transmitter, it is best to use feedback alarms.
What to consider when designing startup?
Such a system can be done if there is data on the time during which the engine starts. It should be noted that the gap can be any, it depends on the state of the piston group, the ignition system and the fuel supply. The reference time value is about 0.7 seconds from the moment the crankshaft starts scrolling to the final start.
It is these data that should be considered when designing an autostart system. If the time is within the permissible values, then car alarms can be used. But if it is larger, you will need to dodge, come up with a design that can provide a guaranteed launch. As an option - the use of a cell phone. But you can connect a relay with a delay. The main thing is the closure of his contacts for the period of time that you need.
Using car alarms
If you need to start the installation in the immediate vicinity of you, then it is quite reasonable to use the simplest car alarms. It has two channels: the first is used for disarming and arming, the second for additional functions, such as autostart or trunk opening. These are frequently used functions necessary for normal operation. But you can do autorun from the phone with your own hands, this allows you to increase the crankshaft scroll time.
But the minus is that the pulse generated at the contacts of the second channel has a small period of time. Usually this is 0.7 seconds, but some models of car alarms allow programming and choosing one of several options. The maximum value of the contact closure time can be 3 seconds.
Correct alarm connection
But not every car alarm model allows you to connect the findings of the second channel to a powerful consumer, such as a winding retractor starter. Therefore, it is required to use additional devices - relays with normally open contacts. It must be connected correctly, it is also required that the entire ignition system begins to function. Therefore, there is a need to use additional relays, the contacts of which will be closed when the signal is supplied to the autostart engine, assembled with your own hands.
The relay windings are connected to the positive terminal of the battery. Management is carried out minus, so it will be much safer. The wires coming from the second alarm channel are connected as follows: the first to ground, the second to the terminals of all relays used. The contacts of these devices are connected in parallel with the terminals of the ignition switch. It is in this place that it is most convenient to connect the entire system.
Programming
In cases where there is a need to increase the cranking time of the engine crankshaft, it is necessary to reprogram the central alarm unit. By default, most models have a time of 0.7 seconds. But the possibility of programmatic increase is not present at all. To do this procedure, you need to refer to the installation instructions. It contains a description of all the functions, as well as how to enter the programming mode.
In addition, you need to connect the Valet button and LED indicator to change the alarm settings. Also, having a speaker instead of a bell does not hurt, so that all settings can be controlled. On cars, the whole procedure consists in turning the ignition on and off alternately. This action needs to be alternated with pressing the Valet button. By the number of blinks of the LED indicator, determine in the settings of which function you are. This is how auto-start of a car is done easily with your own hands. The alarm connection diagram is always provided by the manufacturer.
Using a phone - is it possible?
But what if the engine start time is very long? It is necessary to use a time relay. But this is not always possible to translate, so it is quite reasonable to use a cellular network. In addition, this is true for systems that are located at a considerable distance. Even if you are in another region, it is possible to start a generator, for example, in a greenhouse to conduct heating. But you need to adhere to some requirements, which will be described below. They should correspond to autorun. Do it yourself with your own hands. You will also need to redesign the phone used as a tool for autorun.
System requirements
The most important thing is to limit the circle of people who can call the phone used in the autorun system. You need to prohibit the reception of messages and calls from all subscribers, except for one - the number that you plan to use for management. Even the “do not tell anyone number” option will not help, since it could have been used by someone earlier. And you do not need the engine of the car or generator to start by false commands.
Do-it-yourself GSM auto-start is not very difficult. It will be more difficult to secure the mobile number used in the system from outside calls. But you can do this by contacting your mobile operator. It is worth noting that the scheme may differ depending on which model or vehicle you plan to drive. It all depends on the complexity of the ignition system.
How to connect the circuit?
To make autorun from the phone with your own hands, you need to consider many factors. And do not neglect the blocking of all numbers except one. But the signal to start the starter scrolling process is best taken from a speaker that plays a melody when a call comes in. When you call this phone, voltage appears on the pins connected to the speaker. Now it needs to be directed in the right direction - in the control system.
If the signal level is small (and this is the case), you need to use a simple amplifier circuit with a field effect transistor. If you wish, you can even install an amplifier driver - Darlington assembly. This is a small chip that will increase the signal power several times. But she needs extra food, like a telephone. You need the battery to work as long as possible, for this reason you need to connect power from the vehicle's on-board network.
Precautionary measures
For safety, you should take the habit of not leaving the car at speed. Otherwise, the autostart, assembled with your own hands, will start the engine, the machine will begin to move, since the gear is engaged. It is better to have a good hand brake, but it is not recommended to use it in winter. In addition, keep in mind that you must always block all incoming calls. This measure has been discussed in detail above. All electrical networks must be protected by fuses.
All power circuits of the windings of electromagnetic relays must be connected to the battery only through fuse links. This will prevent fire in the event that a short circuit occurs. However, subject to the use of a car alarm, all protection devices are included in the installation package. It is also worth noting that do-it-yourself autostart of the engine using a feedback alarm is the most reliable and reliable option. And the cost will not be too expensive.
conclusions
There are many autostart management systems, but choosing the one that turns out to be ideal is quite difficult. Try to analyze the costs of various designs. The do-it-yourself autostart module can contain either an alarm or a cell phone. The last option is the most suitable. Especially if you have an unnecessary phone that is capable of receiving calls.
Of the costs - only the purchase of relays, wires and a SIM card. But with an alarm, the hassle will be much less, since it is used in this case for its intended purpose. The only thing that needs to be done is to reprogram. And then this is not always necessary, since usually the closing time of the contacts of the second channel is enough to ignite the air-fuel mixture in the combustion chambers. And the engine starts in less than one second. In some cases, the time increases to three. It’s easier to do the autorun of the generator with your own hands, but you will have to carefully study the connection diagram in order to prevent mistakes during installation.