Electronics portal | Search electronic components online (or old version here) | >20 mln. datasheets | Electronic circuits, schematics, and diagrams | Social network for geeks | Electronics auctions | News about radio electronics | >50k service manuals | Free fonts download | Pinouts collection



Complete list of electronic components suppliers | Complete list of electronic components producers



Doorbell for the Deaf

Circuit : Andy Collinson

Email: anc@mitedu.freeserve.co.uk

Description:

This circuit provides a delayed visual indication when a door bell switch is pressed. In addition, a DPDT switch can be moved from within the house which will light a lamp in the door bell switch. The lamp can illuminate the words “Please Wait” for anyone with walking difficulties.

doorbell circuit

Notes:

The circuit uses standard 2 wire doorbell cable or loudspeaker wire. In parallel with the doorbell switch, S1, is a 1N4001 diode and a 12 volt 60mA bulb. The bulb is optional, it may be useful for anyone who is slow to answer the door, all you need to do is flick a switch inside the house, and the bulb will illuminate a label saying Please Wait inside the doorbell switch or close to it. The double pole double throw switch sends the doorbell supply to the lamp, the 22 ohm resistor is there to reduce current flow, should the doorbell switch, S1 be pressed while the lamp is on. The resistor needs to be rated 10 watts, the 0.5 Amp fuse protects against short circuits.

Source:www.zen.22142.zen.co.uk

VN:F [1.6.9_936]
Rating: 0.0/10 (0 votes cast)
VN:F [1.6.9_936]
Rating: 0 (from 0 votes)

Discuss this article at the forum