Electronics Assistant

Electronics AssistantElectronics Assistant is a Windows program that performs electronics-related calculations. It includes a resistor color code calculator, resistance, capacitance and power calculations and more. Details of calculations can be saved or printed. It provides all the functions found in the calculators section of this site and more in a stand-alone user friendly program.NOTE : Click for better QualityClick...

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Resistor Color Code Generator

Resistor Color Code GeneratorScreen ShotResistor Color Coder is free, and is very useful for determining the color codes or values of 4 and 5 band resistors. To select the mode, click on the 4 or 5 band resistor icon in the upper right corner of the screen. The left hand 3 or 4 bands determine resistor value, the righthand band resistor tolerance.Click the download button to startPassword : electronicsevery...

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Long duration timer circuit

Long duration timer circuit Description This timer circuit can be used to switch OFF a particular device after around 35 minutes. The circuit can be used to switch OFF devices like radio, TV, fan, pump etc after a preset time of 35 minutes. Such a circuit can surely save a lot of power. The circuit is based on quad 2 input CMOS IC 4011 (U1).The resistor R1 and capacitor C1 produces the required long time delay. When push button switch S2...

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Load Sensing Power Switch

Introduction:-This circuit will automatically switch on several mains-powered "slave" loads when a "master" load is turned on. For example, it will switch on the amplifier and CD player in a stereo system when the receiver is turned on. It works by sensing the current draw of the "master" device through a low value high wattage resistor using a comparator. The output of that comparator then switches on the "slave" relay. The circuit can be built...

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LASER Power Supply

Diagram:-click on the image for better quality........................Parts:-Part Total Qty. Description Substitutions R1110 Ohm 10W Or Greater Resistor R21Ballast Resistor, See "Notes" D1, D2, D331N4007 Silicon Diode C1, C2, C330.1 uF 2000V Capacitor T119V 1A Transformer S11115V 2A SPST Switch MISC1Case, Wire, Binding Posts (for output), Line CordNotes T1 is an ordinary 9V 1A transformer connected backwards for step up.R1 MUST be installed...

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Sound Level Meter

introduction:-This nifty sound level meter is a perfect one chip replacement for the standard analog meters. It is completely solid state and will never wear out. The whole circuit is based on the LM3915 audio level IC and uses only a few external components. This circuit can also be integrated into audio amp projects. Diagram:-click on the picture for better view..............Parts:-Part Total Qty. Description Substitutions C112.2uF 25V Electrolytic...

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call recorder

Introduction:-circuit lets you record your phone conversations automatically. The device connects to the phone line, your tape recorder's microphone input, and the recorder's remote control jack. It senses the voltage in the phone line and begins recording when the line drops to 5 volts or less. Diagram:-click on the image for better quality..................Parts:-Part Total Qty. Description Substitutions R11270K 1/4 W Resistor R211.5K 1/4 W Resistor...

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Remote Telephone Ringer

Introduction:-This remote telephone bell ringer allows you to use a large (and loud) external bell in place or in addition to the built in (and rather wussy) ringer in most modern telephones. This is ideal for large outdoor areas, noisy shops or those hard of hearing. Most any large bell can be used as the circuit can be easily adjusted for various supply voltages. Diagram:-click on the image for better quality......................Parts:-Part Total...

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Aircraft Radio Communications Receiver

Introduction:-The communications between commercial aircraft and the ground can be interesting, amusing and sometimes even disturbing. However radios that receive the approximately 220MHz to 400MHz band commonly used for aircraft (both military and commercial) are not easily found. And scanners can be complicated, large and expensive. With an easy to build circuit such as this one, everyone can enjoy listening in on these conversations. Circuit diagram:-click...

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Crystal Radio

Introduction:-The circuit is very simple with only 5 parts, but performs very nicely when used with the right size antenna. Diagram:-click on the image for better view...................Parts:-Part Total Qty. Description Substitutions C11Tuning Capacitor (See Notes) D111N34 Germanium Diode L11Loopstick Antenna (See Notes) SPKR11Crystal Earphone MISC1Wire, Board, Wire For Antenna, Knob For C1Notes:- C1 and L1 can be bought, or salvaged from an...

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Horn Beep Canceller

DEFINITION:-It's a great convenience that most modern cars come with a built in alarm, however it is nothing but noise pollution that the horn sounds when the alarm is armed. Disconnecting the alarm system from the horn relay will eliminate this, but prevent the horn from sounding in the even of an actual alarm. This circuit serves to silence the arming beep yet maintain the alarm by introducing a small delay into the signal. It sits between the...

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