This post is for a Simple Neon Lamp Fuse Blow Alarm Circuit which helps us know when the fuse in the AC mains line gets open or blown. Normally, when the fuse is healthy, current flows through it and the load works in normal condition, when the fuse blows, the load stops working but at […]
Alarm Circuits
LDR Based Morning Alarm Circuit using NAND Gate IC
A LDR Based Morning Alarm Circuit using NAND Gate IC helps switch on an alarm sound automatically when morning sunlight falls on the sensor. This circuit uses an LDR (Light Dependent Resistor) and a CD4011 NAND gate IC to detect light and as soon as sunlight reaches the LDR, the resistance of the LDR changes. […]
Solar Sensor Based Security Alarm Circuit using Transistors
This is a simple and low-cost Solar Sensor Based Security Alarm Circuit using Transistors which uses a solar sensor for light sensing. The circuit gives alarm sound through the speaker when light level changes and it works mainly when darkness comes or when someone blocks light on the sensor. So we can use this circuit […]
Temperature Sensing Alarm Circuit using Buzzer
We already see many temperature detector circuits in out previous blogs, but in this project we show a simple temperature detector circuit, here we use LM335 temperature sensor as good sensor IC and TL071 op-amp IC as comparator. Now, the circuit senses temperature and then gives alert using buzzer when temperature crosses set level, so […]
Car Engine Heat Detector Circuit with Sound Alert
Like in previous post on Automobile Engine Overheat Alert Circuit using LED, where driver gets indication through LED, but in this circuit, driver gets alert through sound and this sound comes from IC 555, which works as astable multivibrator and generates sound signal, also we can adjust temperature level for alarm using variable resistor which […]
Transistor Based Water Level Alarm Circuit
Sometimes water tank gets full which is a common problem But we forget to switch OFF the motor, because of this water gets wasted. So, this simple Transistor Based Water Level Alarm Circuit is useful. It gives sound alert when water reaches a level. Moreover, the circuit is cheap and easy to build as it […]