Simple doorbell Using UM66
Below is a simple circuit of doorbell using UM66. The circuit can be assembled in a general purpose PCB and enclosed in any toys. Parts C1 – 220 µF 10v VR1 – 100 k pot VR2 – 10 k pot…
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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Linux Essentials for Testers
As a software tester, knowledge of basic Linux commands is a necessary. Before going in to details commands we should be aware of some of the facts of Linux OS. Facts You can do almost anything in a terminal which…
How to force install apps to SD card without ROOT
Force install apps to SD card without ROOT Samsung Galaxy Ace has only got 180 MBs of Internal memory. If you install a lot of apps, you are bound to run into low disk space issues. To force your new…
Audio Amplifier using LM386
Audio amplifier using LM386 is a power amplifier designed to be used in low voltage consumer applications. Typical applications are like portable AM/FM amplifier, TV sound systems. It requires minimum external parts and operate from wide range of voltage starting…
Dark Sensor
Dark sensor using 2 transistor BC547 When light falls on LDR, its low resistance drives the transistor T1 into conduction. This keeps transistor T2 cut-off due to low base bias. The LED does not get power as long as ambient light…
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…
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…
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…