Simple Timed Beeper Circuit Diagram

Hi Everyone Yesterday upon visiting my (somewhat) local optometrist, I was advised to look up every 5 minutes or my eyes will stay

Simple Timed Beeper Circuit Diagram

Parts:

R1______220R   1/4W Resistor

R2_______10M   1/4W Resistor

R3________1M   1/4W Resistor

R4_______10K   1/4W Resistor

R5_______47K   1/4W Resistor

C1_______100nF  63V Polyester Capacitor

C2________22µF  25V Electrolytic Capacitor

D1______1N4148  75V 150mA Diode

D2________3mm.  Red LED

IC1_____4081   Quad 2 input AND Gate IC

IC2_____4060   14 stage ripple counter and oscillator IC

Q1______BC337  45V 800mA NPN Transistor

P1______SPST Pushbutton (Start)

P2______SPST Pushbutton (Reset)

SW1_____4 ways Switch (See notes)

PS______Piezo sounder (incorporating 3KHz oscillator)

B1______3V Battery (2 AA 1.5V Cells in series)

Device purpose:

This circuit is intended for alerting purposes after a certain time is elapsed. It is suitable for table games requiring a fixed time to answer a question, or to move a piece etc. In this view it is a modern substitute for the old sand glass. Useful also for time control when children are brushing teeth (at least two minutes!), or in the kitchen, and so on.

Circuit operation:

Pushing on P1 resets IC2 that start oscillating at a frequency fixed by R3 & C1. With values shown, this frequency is around 4Hz. LED D2, driven by IC1A & B, flashing at the same oscillator frequency, will signal proper circuit operation. SW1 selects the appropriate pin of IC2 to adjust timing duration:

Position 1 = 15 seconds
Position 2 = 30 seconds
Position 3 = 1 minute
Position 4 = 2 minutes

When the selected pin of IC2 goes high, IC1C drives Q1 and the piezo sounder beeps intermittently at the same frequency of the LED. After around 7.5 seconds pin 4 of IC2 goes high and IC1D stops the oscillator through D1. If you want to stop counting in advance, push on P2.

Notes:

SW1 can be any type of switch with the desired number of ways. If you want a single fixed timing duration, omit the switch and connect pins 9 & 13 of IC1 to the suitable pin of IC2.
The circuit's reset is not immediate. Pushing P2 forces IC2 to oscillate very fast, but it takes some seconds to terminate the counting, especially if a high timer delay was chosen and the pushbutton is operated when the circuit was just starting. In order to speed the reset, try lowering the value of R5, but pay attention: too low a value can stop oscillation.
Frequency operation varies with different brand names for IC2. E.g. Motorola's ICs run faster, therefore changing of C1 and/or R3 values may be necessary.
You can also use pins 1, 2, 3 of IC2 to obtain timings of 8, 16 and 32 minutes respectively.
An on-off switch is not provided because when off-state the circuit draws no significant current.

Transceiver Homebrew QRP SSB 80M Band

Radio communication transceiver is a radio transmitter at the same time the plane doubles as a radio receiver used for communication purposes. It consists of the transmitter and the receiver are assembled in an integrated way. In mulamula generation, the transmitter or receiver or transmitter and receiver sections are assembled separately and is part of a stand sendirisendiri and can work well sendirisendiri Currently employed both parts are integrated in turn. Aircraft simple transmitter consists of an oscillator generating radio vibration and this vibration after vibration boarded with our voice, in a technique called dimodulir radio, then by the antenna is converted into radio waves and transmitted. As we know that the sound waves we can not reach long distances, although its power is quite large, while the radio waves with a relatively small force can reach a distance of thousands of kilometers. In order for our voice can reach a far distance, then our voice superimposed on radio w...

Mutchus

Search This Blog