A Wailing Siren Circuit using IC 555 is simple to make sound like real siren, going up and down in pitch, also the sound come from 555 IC making pulses at certain speed (frequency). Circuit Working: Parts List: Components Values Quantity Resistors 390Ω, 1k, 220k, 100k, 33k, 22k 1/4 watt 1 each Capacitors Ceramic 10nF […]
Alarm Circuits
Low Battery Indicator with Buzzer Circuit
To begin with, this Low Battery Indicator with Buzzer Circuit is very simple and uses basic idea and few parts. Buzzer make sound when battery is low and warn us and it help us to know when to change the battery so device do not stop suddenly. Circuit Working: Parts List: Components Values Quantity Resistors […]
“Hee Haw” Siren Circuit
The “Hee Haw” Siren Circuit is a fun sound project that makes a high and low noise like “Hee Haw” instead of one long sound. Also, simple electronic components such as resistors, capacitors, transistors and sometimes ICs make up the circuit. The pitch of the sound goes up and down again and again and we […]
Fog Horn Circuit
Ever wondered how fog horns make that deep, spooky sound? In the same way, this Fog Horn Circuit is a small sound-making device that uses electronics to produce the low, rising and falling fog horn noise. Moreover, people use these circuits for fun projects as well as for learning electronics. Circuit Working: Parts List: Components […]
Simple Bedwetting/Wet Diaper Alert Circuit
Simple Bedwetting/Wet Diaper Alert Circuit is one special electronic helper!; it know when someone pee in bed or diaper and then it make sound like doorbell ding ding! So parents or helper can know fast and come for help, it is also good for kids who pee in bed at night or people who need […]
Simple Light Activated Alarm Circuit
This Simple Light Activated Alarm Circuit is like very sharp nightlight, it have small part called LDR which work like a tiny eye. Furthermore, when light goes away fast like someone is moving near circuit it make sound or light happen to warn us. Moreover, it also uses other parts like transistors, resistors, capacitors to […]