This is IC 4060 Timer circuit. When rises time that is set, Suppose set 5 minutes time. after all time to 5 minutes. the circuit will emit a sound of buzzer once. This circuit use volume and switch to set time clock.
-Use 9V battery
-Use current around 23mA (is working) 2mA (at standby)
-Can determine the time between 22 second to 4 hour.
-PCB size : 2.43 x 1.53 inch.
How it works
IC1 (Ic 4060) is a frequency dividers IC, at pin 9, pin 10, and pin 11 are pins for connecting to R, C as frequency generator which can be adjusted by VR1. The signal that divider frequencies of IC1 will send out to pin 1, 2, 3
Next, there are switch as selector to determine alarm time. When timing rises the time setting, at TAP point will has voltage from IC1, send to into both ways. The first passed to D1-diode to the frequency generator sector. To makes IC1 stop the frequencies. And other way will send to through R3-resistors go to pin B of TR1- transistor will works together with R4, R5, C2, TR2 and dynamic buzzer as frequencies generators . Thus the dynamic buzzer so emit alarm sound when to time setting.
How to assemble circuits
A picture putting all components and connecting the external parts as shown in Figure 2 . In assembling the circuit should will begin from a smallest component before to so beautiful and easy, that start with diode as followed by resistors and sort of height and so on. And then for parts has various terminal such as diode , electrolytic capacitors and transistors etc, Be careful in assembly circuit. Before putting these devices to PCB must be coincide.
To connects a 9 volts battery into this circuit, the positive terminal at +9V and then the negative terminal to the ground, and next, rotated fully the volume to MIN.
Slide S1-switch to number 1, then release about 22 second, will emit sound at the dynamic buzzer , and then Take away the 9Volt out.
Slide S1-switch to number 2, then connecting 9V power supply, next release about 45 second, will emit sound at the dynamic buzzer, and then take away the 9 volt out.
Slide S1-switch to number 3, next connecting power supply to the circuit, then release about 90 second will emit sound at dynamic buzzer.
Position 1. can adjust time at VR-500K between of 22 second up to 1 hour.
Position 2. can adjust time at VR-500K between of 45 second up to 2 hour.
Position 3. can adjust time at VR-500K between of 90 second up to 4 hour.
The power supply if do not use often can use the 9V battery. But if use very often. should use 9 volt adapter or this projects :
The detail components
The electrolytic capacitors
The ceramic capacitors
TR1-TR3______________C458, C828, C945, C1815
D1-D3_______________1N4148__75V 150mA Diodes
IC1_________________CD4060___14 stage ripple counter and oscillator IC