35W Tube Power Amplifier with EL34

This is the circuit diagram of 35W Tube Power Amplifier with EL34. This tube amplifier designed in 1953 and worked from 1954 until 1989. If you’re interested with classic circuit and classic components, then you should try this circuit. The circuit is interesting but i think it is hard to find the tubes. Schematic Diagram:

Electronic Siren

This is Electronic Siren circuit diagram which use standard discrete components. The sound produced imitates the rise and fall of an American police siren. When first switched on the 10u capacitors is discharged and both transistors are off. When the push button switch is pressed to 10u capacitor will charge via the 22k resistor. This… Read More »

NiCd – NiMH Battery Charger

Here is the simple and low cost NiCd and NiMH battery charger circuit which can be used for various battery type and size. This battery charger use a regulator IC of LM317. Schematic diagram: The charge will start if a battery is connected between pins JP1-JP4 or JP2-JP4 or JP3-JP4. For example, if a battery… Read More »

2 Watt Mini Audio Amplifier

This is the circuit diagram of 2 Watt mini audio amplifier. This circuit is inexpensive, easy and quite simple. This is general audio amplifier which can be used for computer, CD player or other devices which have headphone output. The circuit was deliberately designed using no ICs and in a rather old-fashioned manner in order… Read More »

LED Flashing Heart

This is the LED flashing circuit, since the shape used in this circuit was hearth shape, then we call it LED flashing heart circuit. The circuit is quite simple, low cost, easy to built. Alternatively, you could be create another shape, not just heart shape. Schematic diagram: Component list: Resistors R1, R2 – 470 ohm,… Read More »

Basic Inverter

The following diagram is the basic design diagram of inverter circuit. The circuit will convert 12V DC to 120V AC. This basic inverter circuit can handle up to 1000Watts supply depends the T1, T2 and transformer used. Please see the note. Basic Inverter Components list: Part Total Qty. Description Substitutions C1, C2 2 68 uf,… Read More »

25W HiFi Audio Amplifier with MOSFET

This is high fidelity, high quality 25W HiFi audio amplifier circuit delivers great audio performance. You don’t need pre amplifier circuit for this design since it can be directly connected to the input devices such as computers, phones, radios, TVs, etc. Component list: R1,R4 = 47K 1/4W Resistors R2 = 4K7 1/4W Resistors R3 =… Read More »