Here is an extremely helpful and dependable circuit of a long-duration adjustable timer utilizing 555 IC or we can likewise say it, long-span time delay relay. The circuit can give a time delay of 2 minutes to a few hours. The time span can be balanced with the 1M variable resistor.
This basic timer can be utilized for a variety of purposes, for instance, charging batteries and automatically detaching them at a preset time, controlling home machines, and so on. The 555 adjustable timer circuit starts timing when turned on. The green LED lights to show that the timing is in progress. At the point when the time frame is over the green LED turns off, the red LED turns ON, and the beeper sounds. The time span sets by altering the variable resistor. It tends to be balanced from 1 to 10 minutes (approximately) with the parts that appeared in the diagram.
Hardware Components
The following components are required to make a Long Duration Timer Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Transistor | 2N3906 | 1 |
| 2. | Capacitor | 220uF | 1 |
| 3. | Resistor | 1K, 2.2K, 470Ω | 1 |
| 4. | Switch | – | 1 |
| 5. | Relay | 12V | 1 |
| 6. | Variable Resistor | 1M | 1 |
| 7. | IC | NE555 Timer | 1 |
| 8. | LED | – | 1 |
| 9. | Diode | 1N4007 | 1 |
| 10. | DC Supply | 9v-12v |
555 IC Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of 555 Timer
2N3906 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of 2N3906
Long Duration Timer Circuit
Working Explanation
A 12V relay is assembled at the output of the circuit because of which you can control the AC or DC device with the circuit.
This circuit works around the 555 timer IC. At the point when the push switch S1 is pressed, the circuit will actuate the 12V relay and a LED for a present time and in this way, any apparatus associated with the relay will be enacted. Increasing the value of the capacitor Cx can additionally build the time duration of the circuit, for instance, a 3300uF capacitor can expand the span to 2 to 3 days.
Applications and Uses
Let us comprehend the use of this circuit:
- For instance, in air coolers, there is a pump that pumps water to the mat. This need not be turned ON consistently.
- Assume that if there is satisfactory water in the tank, the pump must be turned off naturally.
- This can be accomplished by including a level sensor to such an extent that this sensor input drives the reset and repress pins towards the ground potential.
- It tends to be turned ON until cooler mats are wet and afterward it can exchange off. Again, when they are dry it should pump the water.
- This circuit utilizes in such applications where cyclic activity is required
