Sunday, October 30, 2011

Siren Generator Circuit Using UM3561 IC

UM 3561 is a low cost siren generator designed for use in toy applications. The UM 3561 IC can generate Multi siren tones simulating Police siren, Ambulance siren, Fire brigade siren and Machine gun sound. The IC has an inbuilt oscillator and tone selection pins. It is easy to make a siren generator with only a few external components. Only one external resistor and a speaker driver transistor are sufficient to make a simple siren generator.
Siren Generator Circuit Using UM3561 IC
Note:
By changing the pin connections of Sel.1 (Pin6) and Sel. 2(Pin 1) it is easy to change the siren tones.
Sel 1Sel 2Tone
Pin 6 Pin 1
NC NC Police siren
+3V NC Fire Engine sound
Gnd NC Ambulance Siren
NC +3V Machine Gun sound

Supply voltage Min. 2.4VTyp 3V Max 3.5V
Operating current Min - -180 uA

for more details about UM3561 Siren Generator Circuit please visit http://electroschematics.com/4820/um3561-siren-generator-design-2/
[read here...]

Water Switch Sensor Using S201S02 IC

The following circuit shows about Water Switch Sensor circuit based on the S201S02 IC. Features: two closely spaced metal rings are used as the water sensor mechanism.

water circuit switch sensor can be used as applications for: rain alarm, watertap leak detectors, water level sensors for bathroom water heaters, wetness checker for flower pots and more.
Water Switch Sensor Using S201S02 IC
Water Switch Sensor Using S201S02 IC
Working principle of this circuit is very simple. When the sensor rings are bridged by water, an isolated electric switch turns on to activate the load (an alarm, for instance) connected through its switching contacts. Here, the renowned S201S02 solid-state relay (IC1) is wired as the electronic switch.

for more details about water switch sensor circuit  please visit http://electroschematics.com/6259/water-switch-sensor-circuit/
[read here...]

1 Hz Pulse Frequency Generator using IC 555

This is a 1Hz pulse frequency generator circuit using timer IC 555 which is wired as an Astable Multivibrator. The output pulses can be indicated visually by the LED. An Astable Multivibrator, often called a free-running Multivibrator, is a rectangular-wave generating circuit. This circuit can be used in applications that require clock pulses

We can set the 555 to work at the desired frequency by selecting the right combination of resistances & capacitance.

Frequency = 1.44 / {(R1 + 2R2) * C1}

Also, 555 can produce waves with duty cycle else than the 50 % cycle.

Duty Cycle = (R1 + R2) * 100/ (R1 + 2R2)
where duty cycle= Ratio of time period when the output is 1
[read here...]

Wednesday, October 26, 2011

Infrared transmitters using LM3909

Infrared transmitters using LM3909
This is an infrared transmitter circuit of the signal is small and using a power supply of 1.5 V only. by the main electronics are the two LM3909 (oscillator IC LED Flasher) Normally, we tend to put it to work as a simple flashing light circuit. Use a source of low-power 1.5 V, which is working now easier to use transistors. The high frequency is very simple, just change the high frequency device only. C1 and R1 is less than the highest frequency.
[read here...]

Sunday, October 23, 2011

LM3900 Audio Mixer Circuit

 LM3900 Audio Mixer Circuit LM3900 Audio Mixer Circuit

Audio mixer circuit consists of 4 four-channel amplifier (LM3900) two microphone inputs and two audio inputs are available directly online at this circuit. By adding the parallel with this circuit, you can increase the number of entries according to applications. Each input is connected to the inverting terminal of the LM3900.

The amplifier built in each section amplifies each audio input separately and fed to the output terminals. The output terminal of each channel is connected to a single output line with a resistance no greater than 680 and produces a mixture of audio output with low noise. This audio mixer circuit does not use a low impedance input sources to the mix of ideals. Capacitors C1 to C4 are decoupling capacitors corresponding channels. C5 is the decoupling capacitor production.
[read here...]

Monday, October 10, 2011

TV Remote Jammer Using 555 IC

TV Remote Jammer Using 555 ICTV Remote Jammer Using 555 IC

The TV remote control transmits television signals as pulses of frequency around 37.5kHz. Each button on the remote control is pressed or equivalent has a pulse signal codes. This remote transmits pulses of the circuit block of the same frequency as the remote to your TV confuse decoding the transmitted signal.

The heart of the circuit is the 555 timer IC in astable circuit works mode.The output series of pulses at a frequency of 18 kHz to 48 kHz by simply adjusting the 5K potentiometer. What you do is adjust the potentiometer until frequeny jives to its distance from the TV or until the signal is ignored by television.
[read here...]