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 digital fan speed control circuit design that can be utilize to control the speed of 220V fans using induction motor. The speed control is nonlinear, i.e. in steps. The current step number is displayed on a 7-segment display. Speed can be varied over a wide range because the circuit can alter the… Read More »
This is the circuit design of unipolar stepper motor driver to control unipolar stepper motors with 5, 6 or 8 wires. It uses four MOSFET IRFZ44. This circuit can be operated in free-standing or PC-controlled mode.
This is a low cost, simple, yet a surprisingly powerful electronic siren powered by just a 9V battery. The circuit may provide the final circuit block module in an alarm circuit using a relay to activate it.
This is the simple and low cost pulse width modulation – PWM DC motor controller using a MOSFET. This kind connection for DC motor control is to prevent heat and minimize the power consumption. It controls the motor speed by driving the motor with short pulses. These pulses vary in duration to change the speed… 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 inverter 12VDC to 240VDC project can be used to power electric razors, stroboscopes and flash tubes, and small fluorescent lamps from a 12 volt car battery. In contrast to the usual feedback oscillator type of inverter, the oscillator of this inverter is separate from the output stage, which allows easy adjustment of the oscillator… Read More »