A home to software testing, electronics circuits & projects, tips and tricks and digital diary.
A home to software testing, electronics circuits & projects, tips and tricks and digital diary.
Fundamentals of Testing – Testing principles Principal 1: Testing shows presence of defects Testing can show that defects are present, but cannot prove that there are no defects. Testing reduces the probability of undiscovered defects remaining in the software but,…
LED Flasher circuit using NE555 timer IC R1, R2, C1 and the supply voltage determine the flash rate. For a variable flash rate, replace R1 with a 1 MΩ pot in series with a 22k resistor. The purpose of R3…
USB reading lamp is powered using USB port. The USB port provide 5 v and 100mA which is sufficient for this circuit. Cut the one end of the USB cable and use RED(pin1) and Black(pin4) for 5v positive and negative…
RESISTOR COMBINATIONS When we do not get specific resistor values we have to either use variable resistors such as potentiometers or presets to obtain such precise values. Pots are too expensive to use forevery case. Another scheme is to combine…
10 Stage LED Sequencer Components IC1- CD4017 IC2- NE555 C1 – 1μ C2- 0.01 μ R1 – 470 Ω R2 – 100 KΩ R3- 100 Ω LED1-10 – RED LED 9volt DC power supply. …
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…
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…
12v LAMP Dimmer Parts IC 1 – NE555 Transistor – 2N2955 -1 Resistance – 1k(2 no.), 100 Ω Variable Resistance – 50k Capacitor – 0.1 µF Diode – 1N4001 – 3 12v 2 amp Bulb Input Voltage is 12v. To…
Today LED has become an integral part of consumer electronics. LED TV, LED Display, LED Lights and so on. These are becoming very popular because of there low power consumption. What is LED? LED stands for Light emitting diode. A…
Windows default share C$, D$ etc are recreated on machine restart or restarting the server service. To remove these share we can add a batch file which will remove the share. This batch file can be executed every time the…