Hobby electronic kits
The FM30B Digital FM Stereo Transmitter Kit is designed around an RF tight vinyl clad metal enclosure for noise and interference free operation. It has a 25mW output and operates on 13.8V DC to 16V DC...
View ArticleSimple wireless microphone
The wireless FM microphone has a useful transmitting range. Despite the small component count and a 3V operating voltage it will easily penetrate over 3 floors of an apartment...
View ArticleThe Morse code
There are 2 symbols used to represent letters in the Morse code, called dots and dashes. The length of the dot determines the speed at which the message is sent, and is used as the timing reference. A...
View ArticleHam radio - a hobby enjoyed by thousands of people throughout the world
A hobby enjoyed by thousands of people throughout the world - ham radio or amateur radio - uses radio equipment to communicate with other radio amateurs for recreation, public service or self-training....
View ArticleResistor color codes
Commonly used resistors have 4 color bands, but some precision resistors can have 5 or 6 bands. 5% and 10% tolerance resistors usually have 4 bands, with the first 3 aligned towards...
View ArticleInterfacing Microphones to Computer Sound Cards
The approximate schematic of a Sound Blaster soundcard microphone input circuit shows that the +5V voltage on the connector is heavily current limited. The voltage might not be exactly 5V, but it is...
View ArticleMetal detectors theory and a simple BFO detector schematic diagram
VLF or Very Low Frequency, PI or Pulse Induction, VLF or Very Low Frequency are the 3 main metal detector types used today...
View ArticlePower audio amplifier ICs
The TDA2005 is a dual audio power amplifier specifically designed for car radio applications...
View Article170W Audio Power Amplifier
The LM4652 is a fully integrated H-bridge Power Mosfet IC providing a high efficiency amplifier solution suitable for self-powered speakers, car boosters...
View ArticleDigital and analog multimeters
Even if you have only a passing interest to electronics you should consider buying a cheap analog or digital multimeter because it has many uses in the home, on the job...
View ArticleColor codes for computer sound cards
The microphone connector on most computer sound cards will be pink, the line out or headphone will be lime green, and the stereo line in will be...
View ArticleTesting transistors, diodes and mosfets with multimeters
This short tutorial describes common procedures for testing of Si and Ge diodes, Zeners, LEDs, bipolar and mosfet transistors for common failures like shorts, leaks...
View ArticleE24 series resistor examples - color code, range and shorthand notation
A long list of all E24 series resistors from 0.1 ohm to 10 Mohms - with the shorthand notation, tolerance range and color code...
View Article3, 4 and 5 band resistor color code calculator
The calculator displays the value and tolerance of 3, 4 and 5 band color coded resistors. Performs a check to verify if the calculated resistance matches one of the standard values. The resistor value...
View ArticleSMD resistor code calculator
Find out the value of any SMD resistor marked with the three-digit, four-digit or EIA-96 code.
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