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Recently added diagrams and projects
April 25, 2010
If we have a lot of parallel telephones on a telephone line, we needed a unit that will have the possibility of showing if somebody of the telephone has raised the earphone. [more]
April 25, 2010
A very simple circuit, that will find application in the case where you have a lot of telephones installed on a telephone line and would want to know if somebody of them is open. Thus... [more]
April 25, 2010
Many times exists the need recording some conversations from a telephone line and this it's relatively easy. [more]
April 24, 2010
The basic requirements than one laboratorial power supply, it is to provide voltages and currents of operation that need the usual units, to have low output resistance, low noise, small ripple and good stabilisation. [more]
April 24, 2010
The power supply, with electronic stabilisation - mainly those of laboratories - it should they are protected from over current that emanates from short-circuits, erroneous association or damage of repaired appliance. [more]
April 24, 2010
The circuit is based on application of National Semiconductor. First is constituted by three voltage regulators LM338 [IC1-2-3] connected `'in parallel' '. The each one regulator has the possibility of giving 5 A in his... [more]
April 24, 2010
The generators of square pulses, are used in a lot of applications, between which the adjustment of conditions of entry in the digital circuits and the control of amplifiers acoustic frequencies. [more]
April 24, 2010
As it is known the oscillators of bridge WIEN, they are used for the production of sine wave signals in the low frequencies. Basically they are constituted from amplifier of low frequencies, in which is... [more]
April 24, 2010
This circuit is an oscillator at frequency 10MHZ, using IC 1A and IC1B and a frequency divider. Using the IC2 it divides the pulses to 10. IC1C is a buffer. The variable capacitor 39pF is... [more]
April 24, 2010
This is a useful instrument for works hops. The standard of the produced frequencies is 10 to 1. The basic frequency is produced by a crystal with high accuracy. The circuit is consisted by the... [more]
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