Mutchus

This FM transmitter circuit can be used as a wireless microphone,  can be received by an ordinary 88- to 108-MHz FM broadcast receiver. For the power supply, this transmitter circuit is powered by a 9 V battery. To comply with the radiation limit of FCC rules, keep the antenna length under 12 inches. L1 is 6 turns of #24 wire wound around a pencil or a 1/4″ form, with turns spacing of 1 wire diameter. C6 is a gimmick capacitor which has value about 1 pF..  9V Wireless Microphone FM Transmitter Circuit Diagram

By using the circuit you do not bother to roll  up a transformer that is used to reduce voltage AC 220V to 7V ,9 V or 12V, etc. When using a large transformer we will find it hard to make transformator. by rolling hundreds or even thousands of times roll. But if you use this circuit a little just enough to roll trafo not to small, and its be relatively small. Part List : R1________________________________680K R2________________________________47K R3________________________________100R R4________________________________1K R5________________________________1R D1,D2,D3,D4,D7,D8,D9,D10__________1N4007 D5,D6_____________________________1N4148 C1________________________________2u2F 400V C2________________________________2n2 C3________________________________47uF 25V C4________________________________10n C5________________________________470uF / 16V Q1________________________________MJE13003 Q2________________________________S8050 This is construction of transformer. For the first toll 22...

The only thing to do is connect the battery and press the 'Start' button. When the discharge cycle is finished the circuit switches over to charge for 15 hours. After the 15 hours the circuits maintains a trickle charge to keep the battery 'topped-up.  Before I go into the schematic details I like to explain some of the component descriptions in the schematic. Jan Hamer lives in the Netherlands and so the circuit details are based on european standards.  9V Automatic Battery NiCd Charger Circuit Diagram: 120E, 150E, etc. The 'E' just stands for Ohms so 120 ohm, 150 ohm. The original circuit specified the HEF type of cmos IC's which are not readily available in most of Canada. So just get any other type of CMOS chip like the MC4011, MC4020, MC4047 from Motorola. Any other type will do fine too. The BC548B is replaceble by a NTE123AP (NOTE: make sure it is the 'AP' type, the regular NTE123A is a total different transistor), ECG123AP, and the 2N3904 will wo...

A very simple and useful circuit that require few external components and operates in FM band ( above 100 MHz ). This circuit diagram transmitter needs to be powered from a 9 volts battery or from another 9 volts regulated power supply . The tuned coil L1, has two output tappings for the antenna connection, marked "A" and "B". These are both low-level outputs and you choose which tapping you want to use ( stable low range, or more unstable but higher range). Tap B (2.5%) takes just a very small portion of signal from the oscillator circuit and therefore gives a very frequency stable transmitter. The output level (around 2.5mW) and range are therefore somewhat reduced.  Tap A (10%) delivers very much more power (around 10mW) to the antenna load. This gives you a greater range, but at the expense of frequency stability. All component leads should be kept as short as possible. The LINK wire on the PCB should lay flat on the PCB. Use the cutoff from a resistor leg. Ante...

To get a more precise output voltage, replace zener diode Z1 with 10V and R1 with a 1Kilo ohm potentiometer. A Coolrib for Q1 is optional but highly recommended. You can replace Q1 for a more robust type to get more output amps depending on your requirements. Simple circuit to power your 9 volt cassette recorder and other stuff. Parts List: R1 = 560 ohm C1 = 1000uF/40V, Electrolytic C2 = 10uF/25V, Electrolytic C3 = 330nF, Ceramic Z1 = 9.1V, 1watt zener Q1 = ECG184, NTE184