Two-Door Annunciator


Posted on Oct 24, 2012

When the pushbuttons at either door are depressed, this circuit generates a different tone for each door. Tones are ge


Two-Door Annunciator
Click here to download the full size of the above Circuit.

nerated by phase-shift oscillator Q1/Q2. Q3 provides tone frequency change by changing the phase-shift network. U2 and U3 are timers for the tones and Q4/Q5 interface the timers with the pushbuttons.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

White LED Stroboscope
Attiny2313 based LAN cable tester
sap 1 simple as possible computer
Two Channel Audio Mixer
Sound Synchronized LED Video Tutorial
Light control relay control lamp
The basic circuit diagram of a constant current source mirror



Top