Showing posts with label multi. Show all posts
Showing posts with label multi. Show all posts
Monday, May 27, 2013
Multi Colour LED
How many different conditions do you reckon may be signalled with just one LED? Two, maybe three? Using this simple circuit, a lot more! Admittedly, a two-colour LED is used here. Such a device consists of two light-emitting chips, usually red and green, encapsulated in the same case. It has three pins: two for the anodes, and one for the common cathode. In this way, each diode can be activated separately. Various mixed colours may be obtained by varying the current through the two diodes. At least four discrete colours are then easily perceived: pure red, pure green, orange (IR ≈ 2IG) and yellow (IG ≈ 2IR).
In the present circuit, the LED elements are driven by CMOS three-state buffers type 4503, which, unlike most CMOS ICs from the 4000 series, are capable of supplying up to 10 mA of output current. The LED currents are limited by resistors R1 through R6, whose values invite experiments with brightness and colours according to your own taste. The circuit was originally developed to indicate the state of three inputs, a, b, and c (non-binary, i. e., only one of these is at 1 at any time), with the configuration (a=b=c=0) representing the fourth state. The latter is decoded by NAND gate IC1.
An additional effect is produced by gates IC1a and IC1b, which are connected up into an oscillator circuit producing approximately two pulses per second. These pulses are used to control the common-enable input, DA (pin 1) of the 4503, so as to produce a flickering effect. The oscillator is controlled by means of inputs ‘d’ and ‘e’. Pulling both of these logic high disables the oscillator and the LED driver. With e=0 and d=1 the outputs of the 4503 are switched to three-state, and the circuit is in power-down standby mode. Although designed for a 12-V supply voltage, the circuit will happily work at any supply voltage between 5 V and 16 V. Non-used inputs of CMOS ICs must, of course, be tied to ground via 10-100 kW resistors.
[Continue reading]
In the present circuit, the LED elements are driven by CMOS three-state buffers type 4503, which, unlike most CMOS ICs from the 4000 series, are capable of supplying up to 10 mA of output current. The LED currents are limited by resistors R1 through R6, whose values invite experiments with brightness and colours according to your own taste. The circuit was originally developed to indicate the state of three inputs, a, b, and c (non-binary, i. e., only one of these is at 1 at any time), with the configuration (a=b=c=0) representing the fourth state. The latter is decoded by NAND gate IC1.
An additional effect is produced by gates IC1a and IC1b, which are connected up into an oscillator circuit producing approximately two pulses per second. These pulses are used to control the common-enable input, DA (pin 1) of the 4503, so as to produce a flickering effect. The oscillator is controlled by means of inputs ‘d’ and ‘e’. Pulling both of these logic high disables the oscillator and the LED driver. With e=0 and d=1 the outputs of the 4503 are switched to three-state, and the circuit is in power-down standby mode. Although designed for a 12-V supply voltage, the circuit will happily work at any supply voltage between 5 V and 16 V. Non-used inputs of CMOS ICs must, of course, be tied to ground via 10-100 kW resistors.
Tuesday, March 26, 2013
Multi Sound For Guitars
Electric guitars use coils (guitarists call them pickups or elements) to convert the vibrations of the strings into an electrical signal. Usually, a guitar has more than one element builtin, so that the musician can select with a switch which element or elements are used to generate the signal. Because of the differences in construction of the elements and the varying positions of where they are mounted, each element sounds different. The elements can be roughly divided into two categories. There are the so-called ‘single-coils’ and ‘humbuckers’. Single coil elements are elements that contain one core and coil for each string. Humbuckers can be regarded as two elements that are connected in series. Many humbuckers have four connections (actually two single-coils with two connections each).
Multi Sound - For Guitars Circuit diagram :
These two individual coils are usually interconnected with fixed wiring so that they are always used in series. The circuit proposed here offers the possibility of using a hum-bucker with four connections in no less than four different modes, each of which having its own sound. The only things that have to be changed on the guitar are the wiring and the addition of a four-position switch. The latter requires drilling holes in the guitar of course, but if there is a control cover plate (along the lines of a Fender Stratocaster, for example) then it makes sense to put the switch there. This avoids the need for drilling holes in the wood while keeping an (expensive) guitar reasonably unmarred. The schematic shows what the various things look like, electrically speaking, before and after the multisound modification.
Source : www.ecircuitslab.com/2011/05/multi-sound-for-guitars.html
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