August 16, 2004
 |
After locking the door and leaving the keys inside one too many times, Elmer hit upon an entry strategy that involves no keys or codes to remember. He simply attached a timer to his door-bell, and a timer relay to the key switch terminals on the opener for the door on his attached garage. The doorbell operates normally, except when it is pushed continuously for 12-15 seconds, which automatically opens the garage door. Of course, if neighbors or friends find out, you're no longer secure!
For PDF links to Elmer Jones' instructions and drawings:
Schematic drawing of door bell activated delay garage door opener
| Keyless entry system parts list | ||
|---|---|---|
| Amt | Part Description | Allied Part # |
| 5 | Diode 1N4148 | 950-1550 |
| 2 | Disconnect female-12-18 AWG | 617-1481 |
| 1 | Capacitor 220muF25V | 852-7030 |
| 1 | Capacitor 47muF16V | 852-7002 |
| 1 | Capacitor 470muF10V | 852-6500 |
| 1 | Op amp LM741CN | 263-0134 |
| 1 | Reed relay 5V SPST, N.O. | 681-0005 |
| 1 | Resistor 0.5W. 560O | 832-8315 |
| 1 | Resistor 0.5W 680O | 832-8330 |
| 1 | Resistor 0.25W. 22KO | 832-0585 |
| 1 | Resistor 0.25W. 82KO | 832-0703 |
| 1 | Resistor 0.25 120KO | 832-0727 |
| 1 | Enclosure (1 x 1.5 x 2.5 inch) | 736-0061 |
| 1 | Switch, rocker - mini | 676-0032 |
| 1 | Hook up wire 22 AWG solid | 696-9282 |
| Additional parts required: Attached garage, garage door opener, common doorbell, circuit board, solder 1lb 60/40, 21Ga. | ||
Add new comment