High Power Car Voltage Regulator
by P. Marian in Power supply |
While traveling recently, my family had trouble powering the 5 smartphones, 2 tablets, and 2 laptops while driving 2500mi through the southwest. Route 66 and the Grand Canyon are pretty, but in between there are whole lot of straight highways that are not as scenic. This regulator, with the addition of some USB connectors...
Shadow Sensor Alarm
by T.K. Hareendran in Alarms | ECE projects | Lights | Tested |
Shadow sensors are widely used to detect the movement of a person in a confined area. Many circuits published earlier have a serious drawback that only one light dependent resistor (LDR) is used for shadow detection. Needless to say, this is not a perfect solution! Shadow Sensor Circuit Schematic 741 datasheet Described here...
LED DC Voltage Indicator
by Jim Keith in Measure |
This LED DC voltage indicator circuit is a voltmeter, rather than simply a battery tester. As such it may measure voltages as low as 3V. It utilizes venerable LM741 operational amplifiers applied as comparators that drive LED indicators. Voltage thresholds are 3, 6, 9 and 12V. Above each incremental threshold an additional LED...
Rain Sound Generator – Sleep Aid in Case of Insomnia
by P. Marian in DIY | ECE projects | Hobby |
Insomnia treatment consist mostly of sleeping pills consumption but this circuit is an alternative for that and consists of a simple circuitry that generates a rain sound effect. The japanese researches were the first to discover that sound of rain has a relaxing effect. With the help of this simple circuit we can generate the...
Audio Processor Circuit
by P. Marian in Audio |
This audio processor circuit features the SSM2045 IC which was developed specially for electronic music applications and the 741 opamp IC. The circuit is configured as a low pass filter with a DC voltage control for gain. The input signal is set to a working level of 150mVpp through the resistor R1. How does the audio...
DIY Digital Thermometer Circuit
by P. Marian in DIY | Measure |
This diy digital thermometer circuit can measure temperatures up to 150°C with an accuracy of ±1°C. The temperature is read on a 1V full scale-deflection (FSD) moving-coil voltmeter or digital voltmeter. How the digital thermometer works Operational amplifier IC 741 (IC3) provides a constant flow of current through the...