Aaron's Homepage Forum
Aaron's Homepage Forum
Home | Profile | Register | Active Topics | Members | Search | FAQ
Username:
 Password:
Save Password
Forgot your Password?

 All Forums
 Electronics
 Telephone
 Phone Light Flasher modification		  New Topic  Reply to Topic
 Printer Friendly
Author Previous Topic Topic Next Topic  

skipg
New Member

2 Posts
Posted - Mar 21 2007 :  11:43:31 AM  Show Profile  Reply with Quote
I would like to know how I could modify the Ringing Phone Light Flasher circuit to turn off the light when the phone rings. My first thought was to find a Normally Closed (NC) SPST solid state relay, but Digikey only carries the NO flavor.

Thanks,
Skip

audioguru
Nobel Prize Winner

Canada
4218 Posts
Posted - Mar 21 2007 :  10:33:31 PM  Show Profile  Reply with Quote
Add another transistor and a resistor as an inverter like this:

Download Attachment: pflash.PNG
10.42 KB
Go to Top of Page

skipg
New Member

2 Posts
Posted - Mar 23 2007 :  01:45:13 AM  Show Profile  Reply with Quote
Thank you very much!

I'm thinking a further enhancement might be to add a DPDT switch: one side includes the inverter, the other side does not. The switch would then be used as the off/on switch for the light.

There's a commercial product available that does this: the Alertmaster AM-100. It also includes a wireless doorbell.

Since the cost of the transistor and resistor are about 20 cents, you might consider making this part of the published circuit...
Edited by - skipg on Mar 23 2007 1:22:07 PM
Go to Top of Page
  Previous Topic Topic Next Topic  
 New Topic  Reply to Topic
 Printer Friendly
Jump To:
Aaron's Homepage Forum © 1995-2020 AARONCAKE.NET Go To Top Of Page
This page was generated in 0.05 seconds. Snitz Forums 2000