Alert Alarm | Electronic Project Circuits

Posts Tagged ‘alert alarm’

Warbling Alarm Circuit with tone Generator

The circuit is see this it , sound generator warbling tone , which hear distinct in swoop down that have a voice disturb , get more than , single tone. By the transistor Tr2-TR3 assemble the circuit tone Generator , Which frequency modulated with output of TR1 which it frequency generator saw tooth sound generator sound signal can fine can decorate with R7 effectively follow want. And still can fine C1 for make which frequency modulated change to with. By a loudspeaker that use to is supposed to impedance 35 ohm railings are if use lower this be supposed to resistors , build serial keep with. For decrease the popularity will down. And may lead output go to feed reach still power amplifier circuit , get change capacitors 4 uF. The detail is other , see in the circuit yes.

Be the first to comment - What do you think? Posted by admin - January 2, 2009 at 1:57 am

Categories: Alarm systems, Audio diagram Tags: alert alarm, Tone Generator

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 sound with 8-80 ohm small-sized loudspeakers s by use , power supply 9V sizes will arrive at 12V may are battery 12 Voltage all right. For other detail have a few the equipment a little also, request friends have fun this circuit.

Be the first to comment - What do you think? Posted by admin - December 12, 2008 at 9:06 am

Categories: Alarm systems, Audio diagram Tags: alert alarm, LM3900, Sound Alarm Generator

On After Delay with Mosfet

That be On After Delay Circuit. I uses mosfet in the circuit for delay easy more than the transistor. By have the work of the circuit be when press , S1 , an electric bell will not loud suddenly , must wait for follow the period of time that note. The Q2 will get back to the position or Status of Q1. Thus electronics bell will loud immediately after. The time haded delaied until finish already. If enhance the value C1 while delaied long go up. Note: Rs add keep for decrease the popularity of an electric bell , R1 add keep for decrease the time down and decrease the noise give Mosfet. The Q2 use 2N2222 or BC549 or C1815. The circuit is simple this , friends may like , request enjoy please sir.