Simple Siren by 2N2907 Transistor

This be Simple Siren Circuit that build easily. Because of use the transistor 2 pcs only just. Can use 8 ohm size loudspeakers. Which , I uses old loudspeaker , at the sound doesn’t Amen! come to usable with this comfortable circuit. The usability just you presses switch (close) S1 a loudspeaker will utter. Enhance the frequency goes up (C1 , loaded ). When liberate Switch(Open)S1. The sound will decrease the frequency down (C1 , disgorge load ) change the value R1. For change the time goes up – down. Please see circuit picture assembles.

Burglar Alarm Circuit by 2N2222
At this period the economy not good, Make have steal plentiful. We come to try build the circuit steal model to is simple better. The Alarm Sound (Super Bell) loud forever until will cut po ...
Sweeping Output Frequency Siren
This circuit is a variation of the "Two Tone" siren that is a standard for the LM555 timer. The circuit allows the output frequency of the 'B' timer to 'sweep' between two frequencies rather t ...
Car Burglar Alarm system with radio wave signal
When steal open automobile door relay K1 and K2 work make have voltage 12V give radio transmitter and origin sound part for mix radio waves steal will deaf anything sound. Because radio ...
Two Tone Alarm generator using LM3900
This circuit use 2 beep danger sound origins. By use the integrated circuit LM3900 just one. Which compose OP-Amp 4 group stay within the integrated circuit and have , Mosfet , give -ing the s ...
Personal Alarm using IC 74HC04
This circuit uses digital CMOS IC 74HC04 used power supply 3V only. The IC perform produce the frequency about 2.8kHz and 3.3kHz work can alternate into pieces warn to follow want. These hand ...