10 OUTPUT LED SEQUENCER

 10 OUTPUT LED SEQUENCER 

Here is 10 output LED sequencer. After the last LED is illuminated, the circuit is reset.

 This circuit is build around readily available, low cost components - a 555 and decade counter CD4O1 7. 

The timer IC NE555 is wired as an astable multivibrator that produces 6Hz clock at its output pin 3. 

The 4017 is a CMOS decade counter with 10 outputs. Inputs include a CLOCK (Pin 1 4), a RESET (Pin 15), and a CLOCK INHIBIT (Pin 13). 

The clock input connects to a Schmitt trigger for pulse shaping and allows slow clock rise and fall times (not needed in our case).

 The counter advances one output at the rising edge of the clock signal if the CLOCK INHIBIT line is low. A high RESET signal resets the counter to the zero output. 

The circuit may be configured for counts less than 10 by connecting RESET to an output pin (one after the desired count).

 Thus, a five stage sequencer can be made by connecting pin 15 to pin 1. 

A CARRY-OUT signal (pin 12) can be used to clock subsequent stages in a multi-device counting chain. 

 The output from 1C2 pin 3 is connected to clock pin (pin 14) of the IC3 for sequencing operations. 

NPN transistors Q1- Q10 are used to increase the output current for the LEDs which is set by the common 150 ohm resistor. In the circuit, only one of the outputs is HIGH at any one time and the output advances by one count with every clock pulse.

But the circuit above is poorly designed. It does not need the voltage regulator as both chips can work up to 15v. 

 The 4017 can supply 10mA to a LED on a 12v supply so that none of the transistors are needed. The circuit below shows the necessary components.

 The secret to designing a circuit is to look at the final design and ask: "is this component necessary?" 

Try removing a component and see if the circuit still works. Keep doing this with all the components. 

The circuit above was published in an Indian magazine with over 1,000,000 readers.

 The faults were obvious. 

How these faults passed an editorial committee is beyond me. 

They are showing very poor design-leadership in allowing this oversight to be published. 

The faults are technical but are obvious to anyone who has constructed the circuit and experimented with it. Obviously the circuit has never been assembled with anyone with technical expertise. 

CAPACITOR CONVERSION CHART

 

8 MILLION GAIN!

 

8 MILLION GAIN! 

This circuit is so sensitive it will detect "mains hum." Simply move it across any wall and it will detect where the mains cable is located. 

It has a gain of about 200 x 200 x 200 = 8,000,000 and will also detect static electricity and the presence of your hand without any direct contact. 

You will be amazed what it detects!

 There is static electricity EVERYWHERE!

 The input of this circuit is classified as very high impedance.

 Here is a photo of the circuit, produced by a constructor, where he claimed he detected "ghosts."

BUCK CONVERTER for3watt LED

BUCK CONVERTER for3watt LED

 This circuit drives a 3watt LED. 

You have to be careful not to damage the LED when setting up the circuit. 

Add a 10R to the supply rail and hold it in your fingers. 

Make sure it does not get too hot and monitor the voltage across the resistor. Each 1v represents 100mA.

 The circuit will work and nothing will be damaged. 

If the resistor "burns your fingers" you have a short circuit.

The BC557 multivibrator has a "mark-to-space ratio" determined by the 22n and 33k, compared to the 100n and 47k, producing about 3:1 The BD679 is turned ON for about 30% of the time.

 This produces a very bright output, and takes about 170mA for 30% of the time.

 You cannot measure this current with a meter as it reads the peak value and the reading will be totally false. 

The only way to view the waveform is on a CRO, and calculate the current. 

 The 100-turn inductor allows the BD679 turn turn ON fully and "separates" the voltage on the emitter of the BC679 from the voltage on the top of the 3watt LED. 

 When the BD679 turns ON, the emitter rises to about 10v. 

But the top of the LED NEVER rises above 3.6v. 

The inductor "buffers" or "separates" these two voltages by producing a voltage across the winding equal to 6.4v and that's why the LED is not damaged. 

 When the transistor turns off (for 60% of the time), the magnetic flux produced by the current in the inductor collapses and produces a voltage in the opposite direction. 

This means the inductor now becomes a miniature battery and for a very short period of time it produces energy to illuminate the LED.

 The top of the inductor becomes negative and the bottom is positive.

 The current flows through the LED and through the Ultra High-Speed 1N4004 diode to complete the circuit.

 Thus the circuit takes advantage of the energy in the inductor. 

 A 500R pot is placed across the LED and a voltage is picked off the pot to turn on a BC547 transistor. This transistor "robs" some of the "turn-on" for the BD679 transistor to reduce the brightness of the LED. 

 Because the circuit is driving the LED with pulses, very high brightness is obtained with a low current. Our eyes detect peak brightness and you can compare the performance of this circuit with a DC driven LED.

resistor color code