circuit wiring: with

Friday, December 27, 2013

Simple Voltage controlled current source with grounded source and load

This is a Simple Voltage controlled current source with grounded source and load. This is a simple, precise voltage-controlled current source. Bipolar supplies will permit bipolar output. Configurations featuring a grounded voltage- control source and a grounded load are usually more complex and depend upon several components for stability.Voltage-controlled-current-source-with-grounded-source-and-load. In this circuit, accuracy and stability almost entirely depend upon the 100-0 shunt.

Voltage controlled current source circuit diagram

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Friday, April 26, 2013

Light Gate with Counter

The circuit described here counts the number of times that an infrared beam is interrupted. It could be used to count the number of people entering a room, for instance, or how often a ball or another object passes through an opening (handy for playing shuffleboard). The heart of the circuit consists of you guessed it a light gate! Diode D1 is an IR diode that normally illuminates IR transistor T1. The light falling on T1 causes it to conduct to a certain extent. The resulting voltage on the collector of T1 should be just low enough to prevent the following transistor (T2) from conducting. This voltage can be adjusted within certain limits using P1.

Circuit diagram :

Light Gate with Counter Circuit Diagram

As soon as an object comes between D1 and T1, the light shining on T1 will be partially or fully blocked, causing the IR transistor to conduct less current. As a result, the voltage on its collector will increase, producing a brief rise in the voltage on the base of T2. This will cause T2 to conduct and generate a negative edge at IC1. This negative edge will trigger the monostable multivibrator, which will then hold the output signal on pin 3 ‘high’ for a certain length of time (in this case, one second). Atthis point, two things will occur. First, a buzzer will be energised by the output of IC1 and produce a tone for approximately one second. When the buzzer stops, a negative edge will be applied to the clock input of IC2, causing the counter in IC2 to be incremented by 1. IC2 is conveniently equipped with an internal binary-to-BCD decoder, so its outputs only have to be buffered by IC3 and T3 to allow the state of the counter to be shown on the 7-segment display. Switch S1 can be used to reset the counter to zero.

If a one-second interval does not suit your wishes, you can modify the values of R3 or C1 to adjust the time. Increasing the value of R3 lengthens the interval, and decreasing it naturally shortens the interval. The same is true of C1. When building the circuit, make sure that T1 is well illuminated by the light from D1, while at the same time ensuring that T1 ‘sees’ as little ambient light as possible. This can best be done by fitting T1 in a small tube that is precisely aimed toward D1. The longer the tube, the less ambient light will reach T1. The sensitivity of the circuit can be adjusted using P1.

Author : T.Hareendran - Copyright : Elektor

Thursday, April 11, 2013

Laptops Cord Stays off Your Lap with this Clip

Someone just got this trick works on all the uni body Mac Books and helps keep your wires and cord under control.

Hacks and Mods: Laptops Cord Stays off your Lap with this Clip

This clip is especially bendy if you are lounging on the sofa with the power-cord-side in towards the cushions. It keeps your MacBooks power cord under control with this trick and to stop it from tugging in you. Its built-in cable clip the one that keeps your cord wrapped around the power brick and clip it to the side of your laptops screen.

The cable pulls it up off your lap and keeps it neat and tidy not to mention free of crazy fall across the keyboard loops.

Source by : Streampowers

Monday, April 1, 2013

BA1404 Transmitter with UPC1651RF Amplifier

BA1404
transmitter includes onboard RF amplifier for increased transmitting
range. Operating voltage range is 1-3V, the circuit contains FM stereo
mixer, 38KHZ oscillator, FM modulator and high-frequency amplifier
monolithic integrated circuit. As the electronic newspaper BBS there
are many users requiring detailed information on the FM stereo
transmitter, so I re-collect the relevant information on the simple
discrete, merge, integrated FM stereo transmitter experiment, that
BA1404 with μpc1651 mix of the most easy to make and debug, and very
high frequency stability (relative to the previous circuit BA1404),
transmission power is increased by UPC1651RF amplifier.