10 Stage LED Sequencer

Circuit diagram

Components

1. IC1- CD4017


2. IC2- NE555


3. C1 - 1μ


4. C2- 0.01 μ


5. R1 - 470 Ω


6. R2 - 100 KΩ


7. R3- 100 Ω


8. LED1-10 - RED LED


9. 9volt DC power supply.

For power supply you can use 9volt battery or can design separate power supply using step down transformer and 1N4007 diodes.

Variable DC Power Supply using LM317

Variable Power Supply Using LM317

Below is the circuit for variable dc power supply

R1- 240 Ω

R2- 5K VR

R2 can be replaced by fixed value resistor for fixed power supply. Following formula can be used to calculate output voltage.

Vo=1.25(1+R2/R1)

Output voltage should be2 voltage greater than input.

Parts for current setup

 
• D1, D2 - 1N4001
• C1-0.1 μ
• C2 - 10 μ 50v
• voltage regulator - LM317
 

20 Watt Inverter

This circuit will drive a 40 watt fluorescent or two 20-watt tubes in series. The transformer is wound on a ferrite rod 10mm dia and 8cm long. The wire diameters is 0.61mm wire for the primary and 0.28mm wire for the secondary and feedback winding.

The circuit will take approx. 1.5amp on 12v, making it more efficient than running the tubes from the mains. A normal fluorescent takes 20 watts for the tube and about 15 watts for the ballast.

Note: Do not remove the tube when the circuit is operating as the spikes produced by the transformer will damage the transistor

Parts list

1. Transistor – BC338 and TIP 3055


2. Resistance – 47 K, 47 R, 180 R, 2R2


3. Variable Resistance – 100k


4. Capacitors – 100u 16v, 100n


5. On/Off Switch


6.  1 ferrite rod 10mm in 8mm long


7. 30 m winding wire .28mm dia


8. 4 m winding wire .61mm dia


9. 2* 20 watt tube or 1* 40 watt tube


10. 12 v DC power supply

Lamp Dimmer

12v LAMP Dimmer


[caption id="attachment_82" align="aligncenter" width="308"] 12v Lamp Dimmer[/caption]

Parts

1. IC 1 – NE555


2. Transistor – 2N2955 -1


3. Resistance – 1k(2 no.), 100 Ω


4. Variable Resistance – 50k


5. Capacitor – 0.1 µF


6. Diode – 1N4001 – 3


7.  12v 2 amp Bulb

Input Voltage is 12v. To create your own bench top power supply use the circuit shown in http://electronichobbyist.wordpress.com/2012/06/17/regulated-dc-power-supply-circuit/