9 Volt Siren Kit — CK1207 A simple 9 volt siren kit with a surprisingly loud output. Uses voltage controlled oscillator; comes with a half-watt 8 ohm speaker. Good as a sound module to attach to an alarm system, etc.
The following scheme diagram is the circuit diagram of simple easily tuned / adjustable sine and square wave oscillator. With this circuit you can easily generate sine/square wave which can be adjusted both the frequency and amplitude. The circuit uses IC LM101A, a general purpose operational amplifier (op-amp) and IC LM111, a high-speed voltage comparator… Read More »
If you’re interested in RF circuit, then you should know about this basic RF oscillator. This basic RF oscillator circuit is easy to build and the components are not critical. Most of them can be found in your junk parts box. The circuit operated with 9VDC power supply. The L1 antenna col can be made… Read More »
This is the electronic bicycle directional lights circuit that use inexpensive components and is a good substitute to many commercially available versions in the marketplace. This circuit works in an extremely different manner and is convenient to operate.
This is the circuit diagram of car audio system anti theft security which can be effectively used to protect and secure your expensive car audio system from stealing. This simple circuit designed based on popular CMOS NAND chip CD4093,. When the circuit is switched on via switch S1, the indicator LED1 will glow and the… Read More »
This is a portable, 230V high-power incandescent electric lamp flasher circuit diagram. It is actually basically a double flasher (alternating blinker) which could manage two different 230V AC loads (bulb lamps L1 and L2). The circuit is completely transistorised and battery-powered. The free-running oscillator circuit is realised working with two low-power, low-noise transistors T1 and… Read More »
This insect repellent circuit will repel insects such as mosquitoes, flies and cockroaches from your home or yard effectively. circuit uses a specific frequency to disrupt the insect so the insect will go away from this circuit. This insect repellent circuit can be placed inside or outside the home (for speakers). If you want to… Read More »
This is 25W low power inverter which contain of only 9 parts and turn 10VDC – 16VDC into 115V / 60Hz square wave power. This circuit has capability to operate AC equipment up to 25W. The first section of the 555 timer is wires as an astable oscillator with R2 and C1 setting the frequency.… Read More »
This circuit is a powerful three stage, 9V FM transmitter (Tx) with a range of up to 1 kilometer in the open. It uses an RF transistor in its output stage and two BC547″s for the first two stages. Distance of trans-mission is critically dependent on the operating Conditions (in a building or out on… Read More »