Here the circuit diagram of simple and easy made battery level indicator. In general, in mobile phones, the battery levels is displayed in dot or bar style. This helps you to effortlessly acknowledge the battery level. On this page we provide a circuit that helps you to recognize the battery level of a instrument from… Read More »
This is the 220V / 200W lamp flasher circuit diagram. The frequency/speed of the lamp flashing can be adjust with the range of 1Hz to 5Hz. You can use the PR1 variable resistor (trimpot) to adjust the flashing speed. The duty cycle of lamp flashing can be adjusted using PR2 variable resistor.
This is a very simple adjustable analog timer circuit diagram. You can build this circuit just for fun, for newbie project or may be…, this circuit could be used to set a time limit when playing games or as an egg-timer in the kitchen.
This is the circuit diagram of beeper sound. The circuit will generate the sound of a beeper which similar with the one in pagers. It produces a “beep-beep” sound. The work of this circuit is simple, the circuit applied the 555 timer oscillator which is turned ON and OFF periodically.
This is the schematic diagram of Electro-Harmonix Small Stone Phaser guitar effect pedal. The Small Stone is somewhat special in applying Operational Transconductance Amplifiers (OTA”s) for phase shift stages rather of opamps with variable resistors. All of the IC”s are house marked EH1048, but could be replaced with CA3094 that is a combination of an… Read More »
Here is the circuit diagram of battery tester designed by Matthew B.. This circuit can be used to measure the 1.5V and 9V battery. The circuit is very-very simple and very easy to built since it uses five resistors and a panel meter only, and of course it is inexpensive too. Components List: R1 =… Read More »
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 »
The following scheme diagram is the four 4 band equalizer circuit. Equalizer device is generally used to improve the fidelity of sound, to emphasize certain instruments, to remove undesired noises, or to create completely new and different timbres. This circuit operated with 12VDC symmetrical / dual polarity power supply. Power supply circuit provided on above… Read More »
This is a low noise and distortion pre-amplifier and tone control circuit in one module. Using a special IC TDA1524A, this simple circuit is easy to build and will drive most of power amplifier. Schematic diagram: