This is a 1 minute to two-hour timer switch. The 14-stage binary ripple counter Type 4060, IX, has an on-chip oscillator capable of stable operation over a relatively wide frequency range. In the present circuit, the oscillator frequency is determined by an external RC network connected to pins 9, 10 and 11.
Parts List
| R1 | 2.2MΩ |
| R2 | 18KΩ |
| R3 | 1KΩ |
| R4 | 1KΩ |
| R5 | 1KΩ |
| R6 | 1MΩ |
| VR1 | 500KΩ (504) |
| C1 | 220nF (224) |
| C2 | 10nF (103) |
| D1 | LED |
| D2 | LED |
| D3 | 1N4001 |
| Q1 | BC547 |
| IC1 | CD4060 |
| RL1 | Relay |
When the power is on, the pulse at junction R6-C2 resets the counter and counting starts. When the counter reaches bit 14 (Q13), pin 3 goes high so that the relay, a 9V type, is turned on via driver Q1.
CD4060 Pinout
The time delay is set with the aid of VR1. Time delays of between one minute and two hours are possible by appropriate dimensioning of the timing components:
1-30 minutes: C1 = 220nF ; VR1 = 500KΩ. 1-60 minutes: C1 = 470nF ; VR1 = 500KΩ. 1-120 minutes: C1 = 470nF ; VR1 = 1MΩ.
The timer is powered by a 9V PP3 battery. Light-emitting diode D1 does not affect the operation of the circuit and is included merely to show that the timer works. Diode D1 and resistor R4 are , therefore, optional components.
S:electronicecircuits.com
1 comments so far
Circuit is not working confidently I used just 470kohms variable. But it not operating. Can you help me to do it.
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