The following diagram is the schematic diagram of 4 transistors FM transmitter circuit designed by Paul K. Sherby. Components List: R1, R2, R8 = 1K R3 = 100K R4 = 150K R5, R7 = 10K R6 = 220 ohm R9 = 10 ohm P1 = 5K trimpot D1 = 1N4002 Q1, Q2 = 2N3904 Q3, Q4 =....

This Electro Harmonix Big Muff Pi circuit would most likely be better making the change by a contemporary input-jack power and a DPDT bypass switch. The kinds of transistors and diodes are unknown. It really is most likely that any high acq....

TR-55 was the first transistor radio produced and sold in Japan. It uses the following transistors: 2T51 (oscillator-mixer), 2 x 2T52 (for IF), 2T53 (AF driver) and 2T12. The very first commercially produced transistor radio was Regency TR-1 from October....

This project was a sort of challenge: designing an audio amplifier capable of delivering a decent output power with a minimum parts count, without sacrificing quality. The Power Amplifier section employs only three transistors and a handful of resistors and....

This is an amplifier circuit that has a high output power is 1400W mono, the audio amplifier circuit is very suitable when used in a large room, using a woofer speaker, and fullrange. To sound out very nice, loud sound and almost no noise. The amplifier....

Activated this and advisedly destroyed several 2N3055`s by shorting the emitters to ground. In all cases the transistors opened up and no beneficiary to emitter abbreviate occurred in any transistor. In any event, the alternative ambit in Figure 2 will....

The LME49830 EF125WT1 amplifier PCB module showcases National Semiconductor s LME ultra-high fidelity power amplifier input stage ICs (drivers). The LME49830 is a fully complementary bipolar 200V input stage IC with 56mA (typical) of output current that has....

For phototransistors a value of 470K ohms will work for most room light situations. If the light is dim, selecting a higher value resistor such as 1 Megohm will give better sensitivity. This High Impedance Test Voltmeter circuit can also be used for testing....

This simple flashing light circuit is powered with 6 volts/0.5A and has a low current consumption when the light bulb is off. The flashing frequency is set....

CA3140 is the 4.5MHz BiMOS Operational Amplifier with MOSFET inputs and Bipolar output. This Op Amp combines the advantage of PMOS transistors and high vol....

Control a LED with audio signal, but the problem is, that output signal is only 150mVpp (with 150mVpp positive offset). In my understanding, it needs to be higher than 0. 6V to get the transistor running, therefore I am not sure what to use instead. Do I....

The digital lock circuit is composed of the timing trigger circuit, trick lock circuit, sound and alarm circuit and control implementation circuit, and it is shown in Figure 3-101. Timing trigger circuit is composed of the transistors Vl, V2, resistors....

Basically, this circuit is a radio frequency (RF) oscillator that operates around 100 MHz. The audio which is picked up and amplified by the electret....

Designing a simple and yet functional Line Follower Robot (LFR) is always a fascinating and challenging subject to be learned, the LFR actually could be implemented in many ways start from a simple two transistors to a sophisticated PID (Proportional,....

Try the 2N388A transistors as they are dirt cheap (18 cents when bought in lots of 5 or more I think). The 2N5088s can be readily found through Mouser. The rest is pretty much Radio Shack or your local store. Convert to PNP transistors by changing the....

The first choice is usually an integrated circuit designed for the purpose. A typical assortment can be seen on this National Semiconductor page. Discrete designs can also be built with readily available transistors or op-amps andmany designs are featured in....

This is a very simple transistor tester circuit the circuit can be used to test NPN and PNP transistors. The voltage source is a 6V power supply which is 230V AC to 6V step down transformer. It is essential to put the transistor leads in right direction like....

This circuit using power mosfet IRF840 for 60 Watt linear amplifier. The IRF series of power transistors are available in various voltage and ....

The range of this FM transmitter is around 100 meters at 9V DC supply. The circuit comprises three stages. The first stage is a microphone preamplifier built around BC548 transistor. The next stage is a VHF oscillator wired around another BC548. (BC series....

This DIY 12V to 220V voltage converter is build with CMOS 4047 that is the main component of this small voltage converter that transforms a12V DC into 220V AC. 4047 is used as a astable mutivibrator, at pins 10 and 11 will have a symmetrical rectangular....

This circuit is a bistable multivibrator, or flip-flop. Click on the "set" input at lower left to bring the output high (5V). Click on the "reset" input at lower right to bring the output low (ground). The transistors are cross-coupled in such a way that the....

This is the schematic diagram of basic oscillator circuit which using two transistors. When two transistors and a couple of passive components are connected as shown in the figure, the circuit starts to oscillate. The frequency of oscillation can be adjusted....

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This is a design circuit for intercom circuit. The circuit comprises a 3-stage resistor-capacitor coupled amplifier. When ring button S2 is pressed, the amplifier circuit formed around transistors T1 and T2 gets converted into an asymmetrical astable....

A common topology for DC-AC power converter circuits uses a pair of transistors to switch DC current through the center-tapped winding of a step-up transformer Examine these checkplot images from a PCB drafting program, for a control board based on this....

This is a mini FM transmitter built and powered using 2 transistors, designed by Tony van Roon. This small transmitter is simple to build and its transmissions could be picked up on any common FM radio. It possesses a range of approximately 1/4-mile (400....

This project was a sort of challenge: designing an audio amplifier capable of delivering a decent output power with a minimum parts count, without sacrificing quality. The Power Amplifier section employs only three transistors and a handful of resistors and....

Both transistors should be low noise types. In the original circuit, is used BC650C which is an ultra low noise device. These transistors are now hard to find but BC549C or BC109C are a good replacement. The circuit is self stabilizing and will set its....

The following circuit is a cheap completely transistorised inverter circuit ideal for driving medium loads with the order of 40 to 60 watts working with battery of 12V, 15 Ah or larger power capacity. Transistors T1 and T2 (BC548) make a 50Hz multivibrator.....

Here, S1 and S2 are normally open, push to close, press button switches. The diodes can be red or green and are there only to indicate direction. You may need to alter the TIP31 transistors depending on the motor being used. Remember, running under load....

Logic power control of analog regulator can be useful in application where a digital circuit/controller need to control power source, such as in EEPROM programmer or other power controls. This is a circuit provide ON-OFF control for 78xx regulator using....

FM transmitter or often called fm transmitter uses 2 transistors in this article uses 2 transistors 2n2222. If the fm transmitter is in use voltage supply of 9 volt battery and use an antenna whose length is less than 12 inches, then this fm transmitter will....