High Power Car Voltage Regulator
by GaryC 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 would have been useful to...
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 is a simple but improved circuit...
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 turns on. DC Voltage Indicator Circuit...
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 rain sound which can...
Audio Processor Circuit
by Received by Email 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 processor works The...
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 base-emitter junction of npn transistor BC108 (T1). The voltage across...
Sensitive Clap Switch Circuit
by D Mohankumar in Useful |
This is the circuit of a very sensitive clap switch. It switches ON/OFF a White LED or electrical appliances through claps. The circuit can sense the sound of claps from a distance of 1-2 meters. Condenser Mic picks up sound vibrations caused by the clap. These sound vibrations are given to the inverting input (pin2) of IC1. It amplifies...
Panic Alarm Circuit
by D Mohankumar in 555 | Alarms | DIY |
Imagine the Panic situation in the Midnight when an intruder tries to break into the house. This Alarm will help you with its loud Police siren to abort the attempt of intrusion. With a single clap, the circuit generates the alarm for three minutes and then goes off. This is sufficient to catch the attention of neighbours. The circuit...
Dark Activated Relay Circuit
by D Mohankumar in Lights | Tested |
This dark activated switch can trigger a relay to operate an AC lamp at Sunset. The lamp remains on till morning and then turns off. This eliminates the need of switching the Porch lamp or Backyard lamp daily and also helps to light the premises of the house when the occupants are out of station. The circuit utilizes the...
Temperature to Voltage Converter Circuit
by P. Marian in Power supply |
With this simple temperature to voltage converter circuit we can do a precise measurement of the temperature in a room. A NTC resistor or a thermistor is used as a sensor that has a strong temperature dependence. If the NTC temperature rises then the output voltage rises with 0.5 V per 10C. Conversion factor depends on the type of...