Ring Detector
Blinks a LED when there is an incoming call on a phone line.

Hover over a component to highlight it in the part list.
Summary
A device that blinks a LED when there is an incoming call on a landline. If someone gets a lot of calls, it might get annoying hearing the phone ring constantly. This device provides a silent method of knowing when there is an incoming call. It is also compatible with teletypes. It is far less expensive than the products currently on the market that accomplish the same task. It can be used in conjunction with Microphone.
Part List
Component | Description | Origin |
---|---|---|
22K Resistor | Prevents optocoupler LED from burning out. | Salvaged from PCB |
4.7K Resistor | Keeps LED from buring out. | Salvaged from PCB |
1uF 250V Capacitor | Blocks DC while letting ring AC through. | X10 controller |
Diode | Single diode rectifier. | ATX Power Supply |
PC817 Optocoupler | Isolates LED from telephone line. | ATX Power Supply |
Red LED | Ring indicator. | LED Kit |
Gallery
Downloads
File | Size | Description |
---|---|---|
ringdetect.sch | 2.9 KB | Schematic (KiCad) |
ringdetect.pdf | 17.9 KB | Schematic (PDF) |
Timeline
- (10/22/20) Project Build
- (10/23/20) Project Page Finished