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 »

LEDs Temperature Indicator

A well-known IC LM35 is chosen to be the temperature sensor in this circuit. Output voltage of LM35 will increase by 10mV per degree rise in temperature. Output of LM35 is joined to the non inverting input of the operational amplifier (op-amp) of CA3130. The inverting input of the same op-amp could be provided using the required reference voltage using variable resistor R2.

Simple Mic Pre-Amp based LM358

Here the simple mic pre-amp circuit design based on single IC LM358. The circuit is very simple, inexpensive and easy to built. This mic pre-amplifier circuit operated with 9V DC voltage, you may use 9V battery for this circuit. Component Parts List: R1, R3, R4 = 10K R2 = 1K R5 = 100K-1M Potensiometer C1… Read More »

A/B Box Switch 2 Inputs 1 Output with Dual Op-Amps

This is a A/B Box switch pedal schematic with two inputs and one output and featured with dual operational amplifier modules. This circuit was designed by Rick Barker. This A/B Box effect was originally designed for switching between different harmonica mics. This A/B Box featured low noise dual preamp for better performance.

Adjustable Sine/Square Wave Oscillator

The following scheme diagram is the circuit diagram of simple easily tuned / adjustable sine and square wave oscillator. With this circuit you can easily generate sine/square wave which can be adjusted both the frequency and amplitude. The circuit uses IC LM101A, a general purpose operational amplifier (op-amp) and IC LM111, a high-speed voltage comparator… Read More »

Tube Distortion Pedal

The following circuit is tube distortion pedal for guitar effect. The circuit designed by Ron Black. Circuit Notes: IC1 : 747 dual op-amp, other ICs may be substitued but pinout will different. You should check the datasheet IC2 : LM340K-12V Voltage Regulator All resistors are 1/2 W Bridge Rectifier – Full wave bridge recitifier, 50… Read More »