Featured Post

High CMRR Instrumentation Amplifier (Schematic and Layout) design for biomedical applications

Instrumentation amplifiers are intended to be used whenever acquisition of a useful signal is difficult. IA’s must have extremely high input impedances because source impedances may be high and/or unbalanced. bias and offset currents are low and relatively stable so that the source impedance need not be constant. Balanced differential inputs are provided so that the signal source may be referenced to any reasonable level independent of the IA output load reference. Common mode rejection, a measure of input balance, is very high so that noise pickup and ground drops, characteristic of remote sensor applications, are minimized.Care is taken to provide high, well characterized stability of critical parameters under varying conditions, such as changing temperatures and supply voltages. Finally, all components that are critical to the performance of the IA are internal to the device. The precision of an IA is provided at the expense of flexibility. By committing to the one specific task of

Simple LED Electronic Roulette Circuit Diagram

LED Electronic Roulette Game Student Project. This is a Simple LED Electronic Roulette Circuit Diagram. Electronic Roulette (roo-let) replaces the ivory ball with a circuit of flashing light emitting diodes (LED's). In this project Ul (a 4046 PLL containing a voltage controlled oscillator or VCO, two phase comparators, a source follower, and a Zener diode) is used to produce a low-frequency, pulsed output of about 40 Hz. The VCO's frequency range is determined by R6 and C2, which can be altered by varying the voltage at pin 9. 

Simple LED Electronic Roulette Circuit Diagram

Simple LED Electronic Roulette Circuit Diagram
 
The rising voltage causes the frequency to rise from zero to threshold and remain at that frequency as long as SI is closed. When SI is opened, Cl discharges slowly through Rl to ground and the voltage falls toward zero. That produces a decreasing pulse rate. The output of Ul at pin 4 is connected to the clock input of U2 (a 4017 decade decoder/driver) at pin 14 via C3.

U2 sequentially advances through each of its ten outputs (0 to 9) pins 1 to 7, and 9 to 11 with each input pulse. As each output goes high, its associated LED is lighted, and extinguished when it returns to the low state. Only eight outputs are used in the circuit, giving two numbers to the spinner of the house. The circuit can be set up so that the LED's lights sequence or you can use some staggered combination; the LEDs grouped in a straight line or a circle.

Comments