2B-LONG DURATION TIMER
——————– This project works for 24 hours approximately. You can use this project to put OFF any kind of gadget . You can fix the time and your gadget outomatically becomes OFF at the desired time.
TECHNICAL DESCRIPTION AND WORKING
This project has been develped and successfully tested O.K. at TV Engineer’s Technical Lab.
The project is based on CMOS IC 4060. This is a very low expensive project and the provision for an alarm enhances utility of course you can disconnect the alarm by keeping the switch on OFF position. You can set the time at 24 hours or any desired hour further be manipulated by varying the 10 M preset . When we put the supply ON,the pulse corresponding to different hours becomes available at its pin Nos 3,2,1,15,13 and 14. You can set the time for 24 hours on pin NO 3, and for 12 hours on pin No 12. Similarly on pin No 1,15, and 13, you can set the time for 6 hours,1.5 hours and 45 minutes respectively. You can also use rotary switch for this purpose. The pulse from the selected output pin of IC 4060 is fed to pin No2 of UM 66 and the musical output is released through pin No 3 of UM 66. The output is then fed to the base of transistor BC 148 for amplification. The amplfied signal received through
its collector is fed to the speaker,which works as an alarm. If the Alarm is not required put OFF the switch S1 . The alarm goes on ringing as long as the timer IC 4060 is ON. In stead of UM 66, you can also use IC T 325. The output of the IC is also fed another transistor BC 148 which is connected in series with the relay. The relay remains ON when it receives the pulse. The relay can also be replaced by a triac in case equipments consuming more current is to be operated. For using the Triac ,connect its gate to be 148 and earth MT 2 directly.
You can put 5 Amp load in series with MT1 . Use the relay of proper current rating keeping in mind the load [Amp]. Othewise the relay contact may get damaged.
PRECAUTIONS WHILE ASSEMBLING
1.First check all the components as per the circuit.
2.Use IC base for mainting IC 4060. Otherwise the soldering iron heat may spoil the IC.
3.Resistors and condensors should be good quality as accuracy is required for timer circuit.
4.Use speaker of proper wattage other wise UM 66 may get damaged.
5.Avoid short circuit whole soldering
LIST OF COMPONENTS
Type for T O.K. ED Vol II