FM Telephone Bug Posted Apr 24, 2013 at 8:26 am Here is a simple transmitter that when connected to a phone line, will transmit anything on that line (execpt the dial tone) to any FM radio. The frequency can be tuned from 88 to about 94Mhz and the range is about 200 feet. Circuit diagram Parts R1 180 Ohm 1/4 W Resistor R2 12K 1/4 W Resistor C1 330pF Capacitor C2 12pF Capacitor C3 471pF Capacitor C4 22pF Capacitor Q1 2SA933 Transistor D1, D2, D3, D4 1SS119 Silicon Diode D5 Red LED S1 SPDT Switch L1 Tuning CoilMISC Wire, Circuit Board Notes L1 is 7 turns of 22 AWG wire wound on a 9/64 drill bit. Tags: FM Transmitter, phone, Bug Surveillance, electronics tutorials for newcomers learn basic electronics for free
FREE MAGNETIC ENERGY - OPEN SOURCE. Learning Electronics : Free Electric Circuits Textbooks How to Make a Paper Plate Speaker That Actually Works for Under $1 How to Make a Paper Plate Speaker That Actually Works for Under $1 Back in 2007, YouTube user HouseholdHacker posted a parody video on how to make a high-def speaker for under a buck. MythBusters took on the challenge and busted it. Although that particular method doesn't seem to work, that doesn't mean you can't make your own speaker for less than $1.00. To understand how a speaker works, I took one apart. In it's simplest form, a speaker is just a coil of wire glued to a piece of paper, and placed near a permanent magnet. The audio signal from your stereo is a form of alternating current. If this coiled wire is attached to a diaphragm, the vibrations will push a larger volume of air and generate sound waves that we can hear. In the pictures above, you can see a paper speaker cone, the yellow spider (which holds the voice coil in place over the magnet), the voice coil with wrappings of magnet wire around it, and a strong permanent magnet at the bottom of the assembly. Troubleshooting
MyBitBox.com Gapminder: Unveiling the beauty of statistics for a fact based world view. Do It Easy With ScienceProg | We share technology insights and DIY ideas. Wonder How To ยป Show & Tell for Creators & Doers BASIC HOMEMADE TURBINE This turbine design is typical for do it yourself generators because it's one of the easiest to make, and can easily be wind driven. The diagram is only an illustration, and not a blueprint to work from.
The Geek Stuff Electronics Electronics deals with electrical circuits that involve active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies. Commonly, electronic devices contain circuitry consisting primarily or exclusively of active semiconductors supplemented with passive elements; such a circuit is described as an electronic circuit. The nonlinear behaviour of active components and their ability to control electron flows makes amplification of weak signals possible and electronics is widely used in information processing, telecommunication, and signal processing. Today, most electronic devices use semiconductor components to perform electron control. Electronic devices and components[edit] Early electronic components[edit] Vacuum tubes (Thermionic valves) were one of the earliest electronic components. Types of circuits[edit] Circuits and components can be divided into two groups: analog and digital. Analog circuits[edit]