How to make a time relay with your own hands: diagram, video, photo

With the help of electronic relays, you can save a lot at home, for example, take the light in the corridor, closet or entrance. By pressing the button, we turn on the light and after a certain time it turns off. This time should be enough to search for an object in the corridor, closet or get into an apartment. In addition, the lighting does not light up unnecessarily, left on for forgetfulness. In this article we will tell you how to make a time relay with your own hands, providing all the necessary diagrams and instructions.

The simplest option

An example of a constructor for a homemade shutdown delay timer:

If desired, it is possible to independently assemble a time relay according to the following scheme:

The time setting element is the capacitor C1, the standard kit of the kit is 1000 uF / 16 V, the delay time is 10 minutes. Time adjustment is carried out by resistor R1. The board is powered by 12 volts. The load is controlled via contacts. You can skip the board, assemble it on a breadboard.

In order to make a time relay, we need the following details:

A properly assembled device does not need to be set up and is ready to go. This homemade time delay relay was described in the magazine "Radiodelo" 2005.07.

Homemade product based on the NE 555 timer

Another electronic timer circuit for DIY assembly is easy and available for repetition. The element base is assembled on the common chip of the NE 555 integrated timer. This device is designed to both turn off and turn on devices, below is a diagram of the device:

The heart of the device is a specialized microcircuit used in the construction of all kinds of electronic devices, timers, generators signal, etc. This microcircuit controls the load through an electromechanical relay, which can be used both to turn on and off. Sveta.

The timer is controlled by two buttons: start and stop. To start timing, you must press the start button. Disconnection and return of the device to its original state is carried out by the stop button. The node that sets the time interval is a chain of a variable resistor R1 and an electrolytic capacitor C1. The value of the turn-on delay depends on their rating. time relay.

With the given ratings of elements R1 and C1, the time range can be from 2 seconds to 3 minutes. An LED connected in parallel to the relay coil is used as an indicator of the state of health of the structure. As in the previous circuit, this one also requires an external power supply, from a 12 volt DC source.

In order to make the relay start when power is applied to it, it is necessary to slightly change the circuit, and pin 4 of the microcircuit is connected to the positive wire, pin 7 is disconnected, and pins 2 and 6 are connected together. You can learn more about this scheme from the video:

Relay on one transistor

For the very lazy, you can use a time relay circuit on one transistor, KT 973 A, an imported analogue of BD 876. This solution is also based on charging the capacitor to the supply voltage through a potentiometer. The highlight of the circuit is the forced switching and discharge of the capacitance through the resistor R2 and the return of the initial initial position with the toggle switch S1.

When power is applied to the device, the electrolyte capacity begins to charge through the resistor R1 and through R3, thereby opening the key transistor VT1. When the capacitance is charged to the shutdown state, VT1 de-energizes the relay, thereby turning off or turning on the load, depending on the purpose of the circuit and the use of contacts.

Timer elements are not critical and may have a slight variation in values. The time delay may differ and depend on the ambient temperature, as well as on the magnitude of the mains voltage. The photo below provides an example of a finished homemade product:

Now you know how to make a time relay with your own hands. We hope the instructions provided were useful to you and you were able to assemble this homemade product at home!

It will be interesting to read:

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how to make a time relay such that it turns on at 7 am and turns off at 8 am for a power of 1.8 kW or 2,
0 kw, 220 volts

For sale Chinese programmable motor timers (cheap), or assemble an electronic alarm clock type circuit

Somehow a simple time relay was required, controlled by a non-latching tact button that consumes no power after shutdown. As a result, we got the schemes (I attach). Ratings R2 and C1 are selected for T = 4 minutes. In my case, the device was powered by a 3.7V battery. For a different supply voltage, you will have to increase the resistance R1 so that the voltage at the gate of the transistor does not exceed the allowable value. Field-effect transistor - with N-channel, such as IRFS630A, KP501A, KP504A and the like. The diode in the break of the positive power wire (if you are sure that you will not reverse the polarity) can be omitted. I had it to reduce the charging current of the 3.7 V battery from the USB socket of the computer. To switch a powerful load or connected to a 220 V network, use a circuit with a relay.