This is the circuit diagram of portable mic preamp. This circuit consumes low current supply (about 2mA), so will have a long battery life for supplying the circuit. Harmonic distortion is about 0.1% @ 1V RMS output for all frequencies. Maximum input voltage (level control cursor set at maximum) = 25mV RMS. Maximum input voltage… Read More »
This is a HiFi pre-amplifier circuit diagram with low noise output. Very wide range frequency from about 10Hz until up to 100Khz will be gained by this preamplifier for maximum audio performance. This circuit uses BC550C / BC560C transistors as active component. Use regulated power supply 15VDC for maximum result.
This 4W Audio Amplifier circuit is powered by 2 pieces of transistor TIP41. The circuit is very simple and incorporates darlington output transistors that will provide more than enough output current than is needed to drive a 3-ohm speaker. The 4W audio amplifier circuit is very simple and incorporates darlington output transistors that will provide… Read More »
Here is the hum remover circuit diagram. “Hum” usually occured from live audio system, for example: input from microphone. Hum can be removed from an audio signal to get the maximum performance by mixing the actual hum with an antiphase hum in equal level. You can use any NPN transistor to support this circuit.
This is the circuit diagram of dancing LEDs which consists of 10 units LEDs. The 10 dancing LEDs circuit works like a audio level meter. The LEDs will be dance sequence with the sound level that entering the microphone. Components list: R1_____________10K 1/4W Resistor R2,R3__________47K 1/4W Resistors R4______________1K 1/4W Resistor R5,R6,R7______100K 1/4W Resistors R8____________820R 1/4W… Read More »
This is a dual regulated and stabilized power supply, usually used to supply amplifier circuit, it also known as split powersupply. There are 3 output that are (+) voltage, (0) Ground (normal), and (-) voltage. The current output max about 0.3-0.5 A. For higher current output, power transistor is needed. Please take a note that… Read More »
Here is the circuit diagram of ultrasonic sensor switch. There are many methods of wireless switching such as by using infrared, AM/FM signal, bluetooth, etc. This is an alternate wireless switching by using ultrasonic sensor. The distance of switching range should be more than 10 meters. This circuit produces and transmits ultrasonic sound of frequency… Read More »
This is another 100 watt inverter circuit diagram. Built based on IC CD4047 and Mosfet IRF540, this inverter have ability to supply electronic device -which require 220VAC- up to 100w from 2-3A transformer from 12V lead acid battery. In the circuit diagram we can observe that 12V battery is connecter to the diode LED and… Read More »
This is the 300W inverter circuit which capable to convert 24VDC become 220VAC. With this circuit, you will have 220V AC power with 300W max rated, from 24V lead acid battery or accumulator. Schematic diagram: PCB layout and component placement: