Doorbells
Circuit / Schematic diagram of | Description |
555 Timer based door bell | Timer used in astable multivibrator mode to generate tone |
3 Tone Gong | Based on SE800 with adjustable speed of melody |
Doorbell with Counter | Based on a synthesized sound chip from Holtek, the HT-2811. |
Electronic Canary (Doorbell) | Bell constructed by modifying Hertley Oscillator |
Fix Adds Door-Chime Repeater | Timer based door bell |
Multi-Switch Doorbell with Indicator | |
Self-Powered Door-Bell Watcher | Allow a person to monitor if someone has rung his home door-bell when he was out. |
Remote Doorbell Indicator | This circuit will light a lamp when doorbell switch is pressed |
Birdie Doorbell Ringer | |
Ding-Dong Bell | |
Doorbell for the Deaf | This circuit provides a delayed visual indication when a door bell switch is pressed. |