This is a 12VDC to 9VDC converter circuit. You may use this DC to DC stepdown converter circuit if you have fixed 12V power supply / battery, but you need 9V power supply for your electronic devices. Scheme Diagram: Components List: R1________ 560 ohm, resistor C1________ 1000uF/16V, Electrolytic capacitor C2________ 100uF/16V, Electrolytic capacitor C3________ 330nF,… Read More »
This is a very easy and simple LED flasher with only three components: a flasher IC LM3909, a LED indicator and an electrolytic capacitor. The supply voltage is 1.5V, so it can be operated using a 1.5V battery which can be easily found on market. Component list: LED1 _________ Red LED C1 ___________ 100uf/16V IC1… Read More »
Here the simple and low cost FM transmitter circuit. The frequency range of this FM transmitter should be about 89MHz – 109MHz. Output power is about 9mW at 9V. Components List: Resistors: R1, R6 : 12K R2, R4 : 100K R3 : 22K R5 : 1K R7 : 100R Capacitors: C1 : 10uF/25V C2 :… Read More »
This a two station intercom. It uses two wires to run between each intercom unit. Each is self contained with its own battery, speaker, microphone and amplifier circuit. An LM386 audio power amplifier is used. It is widely available, used a minimum of external parts and is well suited to battery operation. It will give… Read More »
Here the circuit diagram of safer security system alarm. There are many security systems use a closed loop of wires and switches arranged so that whenever a door or window is opened, the loop will be broken and the alarm will sound. An obvious problem is that someone can tamper with the system, short out… Read More »
This is 68W power audio amplifier circuit which built based on single IC LM3886 from National Semiconductor. A LM3886 used for single channel operation. Dual polarity / split / symmetrical power supply used to operate this amplifier circuit. The LM3886 is a high-performance audio power amplifier capable of delivering 68W of continuous average power to… Read More »
This is a sound generator based on general purpose timer IC 555. A flip-flop circuit is included, so this circuit will give sound output and blinking LED. There are 2 modules in this circuit that are flip-flop / LED flasher module and sound generator circuit modules which combined in one schematic diagram. This is a… Read More »
This is 1W stereo audio amplifier with LM386N. The output power is 1 watt for each channel, so it should be use two ICs of LM386N National Semiconductor for stereo channel. This circuit belongs to kitsrus.com and the kit is available there or at electronickits.com. This circuit only need 10mA current with best voltage supply… Read More »
This is the circuit diagram of 1W audio amplifier which use TDA7052 as the main component and other 5 pieces of components to support the main component. The ideal supply voltage of this circuit is about 6-12V and no heatsink required. The schematic is for mono audio channel, just build two similar circuit for stereo… Read More »