USB Reading Lamp
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…
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.
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Basic Electronics – Resistor Combinations
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
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. …
LED Basics
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…
Regulated DC Power Supply Circuit
Below is the regulated DC power supply( 12, 8, 5 v) circuit. This circuit can be customized by adding 9v and 6v voltage regulator. Also, the 4 diodes can be replaced by bridge rectifier. Parts list: T1 – Step down…
Basic Power supply circuits Part 1
To understand power supply circuits, we need to understand rectifiers. A rectifier converts AC or alternating current to DC direct current. Rectifiers are used in Power supply circuits which we will discuss in detail. The process of converting AC to…
Truth about test plan document & test case document
Truth About Test Plan Documents – 98% of test plan documents that are created are not updated, maintained or cared beyond sign off. – The first 5 pages of a test plan document contains history that doesn’t interest even those…
Fundamentals of testing – Why is testing necessary?
Why is testing necessary? Testing is necessary because we all make mistakes. Some of those mistakes are unimportant, but some of them are expensive or dangerous. We need to check everything and anything we produce because things can always go…
Basic Electronics – 2
Passive Components RESISTORS To oppose the flow of electrons ( current). The symbols are shown below. Resistance is measured in units called “Ohm”. 1000 ohms is shown as 1k ohm (103 ohm) and 1000 k ohm is shown as M.ohms…
No Sound from Ubuntu linux or Mint
No Sound from Ubuntu linux or Mint Searched google for possible answer to the problem but solution mentioned was not sufficient to solve my issues. I wasted couple of weekends resolving this issue.Finally I solved by removing PulseAudio and ALSA…