Here is the circuit diagram and PCB design for relatively low cost DIY bass guitar preamp pedal uses FET K117 or equivalent. There is a bit difficult to build this kind circuit project, it’s require a good knowledge in electronics. This preamp has several features for the bass guitar instrument such as attenuator, low cut, mid… Read More »
This is a 200W power amplifier circuit project. The circuit features high power, good definition and very low noise. It delivers about 200 watts in 4 ohms loudspeaker: a 4 ohm speaker or two pieces of 8 ohm speakers in parallel. This 200W power amplifier using the complementary transistors of 2SC5200 and 2SA1943 as the… Read More »
This is the simple project of small sound amplifier for ears or often called hearing aid device or hearing loss amplifier. This circuit was already tested on some patients and give significant improvement in the hearing ability to the patients. It consumes a very small amount of power within the range of 10 milliwatts. Furthermore,… Read More »
This is the schematic diagram of 400W RMS stereo power amplifier which use power transistor to work. This amplifier in addition to providing good sound power, also with excellent quality and a high fidelity with low noise, to obtain the 400 watts we can put 2 speakers of 4 Ohms or 4 of 8 Ohms.… Read More »
This is a simple active speaker protector circuit which has a very important use, expecially to protect the loudspeakers of a audio system. It prevent the speaker from noise sound when we turn on the power amplifier. The circuit drives the speakers after 3 to 10 seconds so that the source of the same stabilizes… Read More »
This is the circuit diagram of two tones train horn which built based dual timer IC NE556. The circuit is quite simple and easy to built and of course inexpensive. The circuit diagram is in a “basic” design, you may try to modify this circuit, for example: use a low power audio amplifier and use… Read More »
This is the circuit diagram of TRIAC, SCR and Transistor tester. This is a very simple circuit which can be used for testing of SCRs as well as triacs. The circuit could even be used for checking of PNP and NPN transistors. The circuit works on 3V DC, derived using a zener diode in conjunction… Read More »
Here is the USB printer switch circuit design with two USB input ports and one USB output port. This a really simple device that allow two computers (desktop/laptop) to select a single USB printer or some other USB device, such as an external flash drive, memory card reader or scanner. A rotary switch selects the… Read More »
This is a really simple smoke alarm circuit design. The circuit consists of two important modules that are sensor module using a photo interrupter module and alarm module using a tone generator IC NE555 with astable multivibrator configuration and then connected to the speaker, so you can hear the alarm sound.