This is the circuit diagram of 12 Volts, 4 Amperes Solar Photovoltaic (PV) battery charger which will be suit to charge a 12V battery or accumulator. The circuit handles up to 4 amps of current from a solar panel, which equates to about 75 watts of power. A charging algorithm called “pulse time modulation” is… Read More »
This ding-dong door bell circuit might become the simplest and cost-effective door bell circuit. The circuit is designed based on single IC 8021-2 which manufactured Formox Semiconductors. It is an 8-pin DIP (Dual Inline Package) IC whose only four pins, as shown in the above circuit design, have been used.
This is a low-cost and simple intercom circuit design. Some intercom circuits is build by applying integrated circuits. The circuit described right here utilizes 3 certainly transistors which easy to find on the electronic store. Even a newbie can assemble it on a piece of veroboard without difficulty. The circuit consists of a 3-stage resistor-capacitor… Read More »
This is the FM transmitter circuit which apply 4 radio frequency stages, that are a VHF oscillator designed around transistor BF494 (T1), a preamplifier designed around transistor BF200 (T2), a driver designed around transistor 2N2219 (T3) and also a power amplifier designed around transistor 2N3866 (T4). A condenser microphone is wired at the input of… Read More »
Here is the Hi-Fi compressor circuit with pre-emphasis. The above diagram is a circuit for a high fidelity compressor which uses an external op-amp and has a high gain and wide bandwidth. An input compensation network is required for stability.
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 »
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 »
Here the simple mixer circuit with 4 inputs and 2 operational amplifier (op-amp) modules: A basic mixer suitable for mixing microphones or even effects outputs. The overall gain from input to output is one if the pot related towards the input is full up. You can make this a net gain of ten (or any… Read More »
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.