Here the 35W power audio amplifier circuit based on LM391. Inductor L1 is constituted by 20 coils of wire, with thickness 0.9mm, round resistor R16. The transistors Q3-4 are the final amplification section, it should be placed on heatsink. If are used the Q3-4 in packing TIPxxxx they can be placed straight above in PCB.… Read More »
This is the circuit diagram of 18W audio amplifier. The circuit is quite simple and inexpensive to built. It uses a pair of power transistor TIP41A and TIP42A for single channel operation. The power supply used for this circuit is dual polarity (splitted) power supply, use center tap transformer to build this kind of power… Read More »
This is the circuit diagram of zener diode tester which tests zener diodes with breakdown voltages extending up to 120 volts. This is a handy circuit and will help you to measure the zener diode easily. This diode zener tester can be fitted in a 9V battery box. 1/3 of the box may be used… Read More »
This is a simple low cost circuit of an active FM booster that can be used to amplify the FM band signal, so you can listen the FM channels/programs from distant FM stations clearly. The circuit make use of a common-emitter tuned RF preamplifier wired around VHF/UHF transistor 2SC2570. (Only C2570 is annotated on the… Read More »
The DS1669 is an electronic digital rheostat manufactured by Dallas Semiconductor. This component has a function similar to digital variable resistor/potensiometer which can be operated by push the buttons. You can adjust the audio volume, LCD contrast, frequency, etc. by using two buttons instead of a common potentiometer/trimpot. This circuit explains how we do it… Read More »
This is 2 way speaker box design for audio system. I’ve used this design for my home audio system, the sound quality is good. Two speakers used for this speaker box that are tweeter / high frequency speaker and woofer / low frequency speaker / subwoofer. Alternatively you may replace the woofer with fullrange loudspeaker.
This is the circuit diagram of USB power booster, expecially to strength the power capability of USB port from PC / laptop / notebook. USB from PC can supply only a limited power to the external devices connected through its USB port, when too many devices are connected simultaneously, there is a possibility of power… Read More »
This is 220V 800W lamp flasher circuit directly connected to 220V mains. One or more lamp which has high consumption / power can be used. It is ideal for signage warning or danger, this circuit flickers the lamps. The work of this circuit is simple. The 400V capacitor, the bridge rectifier, the zener diode and… Read More »
MK484 Datasheet Document The MK484 is a monolithic integrated circuit designed in a TO92 package for use as a one chip radio solution, high sensitivity and high quality AM radio is possible with very few external components. Special features of the circuit include low supply voltage operation, the Device is particularly suited to small hand-held… Read More »