4 Watts FM Transmitter

The following diagram is the FM transmitter circuit with FM transmision up to 4W. Voltage supply for this circuit is 12-16V with current consumption of 100-400mA. This circuit works with frequency of emission range of 88-108MHz. Transistor 2N2219 used as the main signal amplifier. 4 Watts FM Transmitter circuit design: Components List: R1, R2 =… Read More »

400W Power Amplifier “Safari”

This 400W power amplifier circuit often called as “safari” amplifier. The below circuit design is for single channel only, build two identical circuit for dual/stereo channels. The 400W power amplifier designed using two couples of power transistors that are TIP31 with TIP32 and 2N3055 with MJ2955. These types transistor are well known and widely used… Read More »

5V/10A 50W Offline Switching Power Supply

The following diagram is the 50W offline switching power supply circuit design. The circuit powered by a MOSFET. BUZ80A/IXTP4N8 for 220V AC voltage input and GE IRF823 for 110V AC input voltage. The output will be 5VDC with electric current up to 10A. The schematic diagram: Components list:

4 Transistors FM Transmitter

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 = 7001, NTE123AP C1… Read More »

Safe Constant Current Source

In the above circuit diagram, a CMOS operational amplifier (op-amp) controls the current via a P-Channel HEXFET power transistor (IRF9520) to maintain a constant voltage across R1. The current is given by: 1 = VREF/R1. The benefits of this configuration are:

2 Transistor Mini FM Transmitter

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 meters) or even more, depending on the line-of-sight, obstructions by big… Read More »

3A Switching Voltage Regulator based LM317HV

Above circuit diagram is a easy, simple and cheap switching voltage regulator which has capability to deliver adjustable voltage output range of 1.8V to 32V and static electric current of 3A. This regulator use adjustable regulator IC of LM317HV and a power PNP transistor of 2N3792.

PNP Boost for Positive Voltage Regulator

This is the positive voltage regulator circuit with PNP Boost transistor: The IC8211 presents the voltage reference and regulator amplifier, while Q1 will be the series pass transistor. R1 defines the output current of the IC8211, while C1 and C2 present loop stability and as well act to suppress feedthrough of input transients to the… Read More »

Small Audio Booster

Here the simple, low cost and easy audio booster circuit. It uses a transistor of 2N3392 ad the main amplifier. Component List: R1 = 47K R2 = 470K R3 = 10K R4 = 560R R5 = 270R C1 = 0.1uF/25v C2 = 3.3uF/25v C3 = 470uF/25V P1 = 100K Q1 = 2N3392 D1 = 5mm.… Read More »