| 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. |
