momename 's Public Library

In the circuit shown, Twin-T network connections with LM102 in form of High Q notch filter.
Usually, the junction of R3 and C3 to ground, is bootstrapped to the output of the follower. [...]

Notch Filter

This circuit design, to determine quickly the transistors only. when not have time,or need to check the a lot equipment. This circuit have a simple way to work,In the test battery position

fast-transistor-checker transistor-test-hfe transistor-tester-project

This circuit is maintain a constant voltage, the output voltage is adjustable.Serves to reduce the input voltage, and keep the voltage constant.

2n3904 constant-voltage-control transistor-dc-converter

This is an SCR control circuit with digital logic. The behavior of the circuit. The input A to control current for SCR turn ON.The input B will stop the current SCR (OFF). Set the two input signals to a logic “1″ to control, and it asked them to different times.

digital-control-systems scr-control-circuits

The detect ringing signal tone circuit with light and sound.It is easy to use and good quality, Do not enter the power supply. Which as Detect ringing signal tone circuit Or ring tones on the telephone line

detect-ring-signal telephone-ring-signal

A mini roulette circuit, When the switch S1 the output at pin 1 of the IC1a the voltage is “high”,The oscillator circuit output IC2b, IC2c work.Clock pulse generator fed to IC3, a voltage

digital-game led-roulette-wheel-circuit

Rotary switches electronic circuits, using a single switch choose a function of external control circuit has 9 positions.Work was, when the switch S1, the output signal from pin 2

electronic-switch-timer rotary-electronic-switch

This circuit will allow the brake light was flashing.The default behavior. When the power supply to the circuit, Or tap the brake it.The IC timer IC2 drive current to transistor Q2 and producing oscillator output, pulse signal output at pin 3 to input pin 1 of IC1.

car-brake-lights flashing-brake-lights

This is a time delay switch on the monitor. The contacts of the relay acts as a switch.The contacts of the relay, acting as a switch.When entering into the 220volt mains.

monitor-controls-circuit power-on-delay-circuit

High-frequency amplifier circuit,Wide frequency band between 75-150 MHz,Using transistors, a PNP amplifier.To enhance the signal strength.Before the receiver of the phone. Or FM radio or amateur radio.

high-frequency-amplifier wideband-amplifier-circuit

A motion detection alarm circuit using a PIR.SENSOR motion detection, if the move is a positive light from the PIR sensor, triggered by a delay circuit, Q1 and relay it to work and hold for about 20 seconds.

pir-motion-sensor-alarm-circuit

Small stereo amplifier,low power, less devices, IC TDA7025 is the main equipment. Operation of the circuit, the signal split into left and right through the capacitor coupling of C1, C2 is a variable resistor VR1 adjusts the strength of the input signals to bridge amplifiers

small-stereo-amplifier tda7025

Operation of the circuit. Wreath switch S1 to detect the magnetic field. By S1 on the circuit.When a magnetic force drew near.When the magnetic field out away.It works in conjunction with resistors R1, R2 and capacitor C1.

measure-distance-meter

Mini switch control circuits with light, by used the photo transistor is a light sensor, and Schmitt Trigger output drive current, Out a load or an external circuit,can supply up to 25 milliamps.

light-switches-controlled optocoupler-circuit schmitt-trigger-buffer

The Door buzzer sound circuit was two-tone sound. With the switch S1. working of circuit,The IC1 is a frequency dividing circuit, and generator a sound frequency came out.by the C1, R1 are the frequency generator.

buzzer-driver-circuit buzzer-sound door-buzzer-sound

The working principle of the circuit. Start step, dc voltage power from the secondary coil of the transformer will be charged to C1. through D1.When the switch S1 to the circuit, current flows through relay contact at the NC,And flowing through the load, R1 and VR1.

over-load-protection overload-protection-for-transformers

Now my son, age 5 years.I want to find a good event for him in free time.Future he would be happy to create electronic projects. So I find information about Beginner electronic learning.

learning-electronics-kit

This is a siren sound generator circuit. Which is less expensive and can create simple. The IC1 is using CD4011 (Digital Nand Gate) and the IC2 is CD4046.

cmos-digital-ic siren-sound-circuit

You checked the transistor by measuring the resistance between the different pins. Sometimes it has problems, such as when measuring the resistance between the various legs correctly. But it does not work in the real circuit.

buzzer-sound transistor-checker-circuit transistor-tester-circuit

This is Coaxial cable tester circuit.It is useful to check the cables inside and outside. Check the continuity of the cable, check cable short-circuited. And detection of the high resistance of the cable. Check that all lamp displays with LED.

coaxial-cable-tester wire-detector