Convert doorbell chimes to wireless

Thread Starter

Leclanché

Joined Nov 29, 2013
3
Having had a new £1050 front door fitted I did not want to drill the frame to reconnect the rather nice tubular chimes so bought a wireless chime and am attempting to use the TX and the RX portion to close the chime circuit.
The chime runs on 6V from 4 type C cells. The RX was mains stepped down and rectified.
This is as far as I have got. See attachment.
Vcc is 3.5v. No LED was installed, but from the solder pads I can see a fluctuating voltage in step with the tune. There is of course a trigger pulse from the decoder. I do not own a scope so things are a little hazy from here!What I need now is a circuit to replace the old bell push ie make (ding) and break (dong) and I shall be home and dry. Any ideas will be appreciated.
 

Attachments

MaxHeadRoom

Joined Jul 18, 2013
21,268
I must be missing something, the T.N. looks like the receiver or chime which should be no problem, Isn't it the TX you want to trigger somehow?
Max.
 

#12

Joined Nov 30, 2010
18,210
I have had a customer waiting for a GOOD wireless door bell for a year. Everything I can find will not work as advertised. The best of them fail 4 out of 5 times at 25 feet, line of sight. Not a chance they can go 50 feet and around 2 corners made of grounded concrete walls. Please post if you find quality!
 

Dodgydave

Joined Jun 22, 2012
9,320
I would look at the receiver cct to see if it gives a dc voltage pulse out when you press the door bell TX,and use that to trigger a 555 timer and relay.
 

Thread Starter

Leclanché

Joined Nov 29, 2013
3
I would look at the receiver cct to see if it gives a dc voltage pulse out when you press the door bell TX,and use that to trigger a 555 timer and relay.
The decoder gives a trigger pulse (I can only see the volt meter jump, having no scope to see it's shape) witch I am sure can be used to trigger a 555. I guess what I should be asking for is the 555 circuit details required to be triggered by that pulse and then give me a suitable square 'ding dong' pulse.

My basic problem is that I am a 82 year old wind up watch man in a digital world :D
 

Alec_t

Joined Sep 17, 2013
11,540
I guess what I should be asking for is the 555 circuit details required to be triggered by that pulse and then give me a suitable square 'ding dong' pulse.
Doable. What voltage/current does the tubular chime require? Is the pulse a positive-going one relative to the battery -ve?
 

Dodgydave

Joined Jun 22, 2012
9,320
Here is a timer cct that will give out a pulsed relay for upto 4 seconds, make the 220k resistor a variable one, if the pulse from the receiver is a posative one then connect it to the 10K resistor to trigger the transistor, if its a negative pulse then connect it to pin 2 direct.

use the relay to connect the original door push.
 
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Thread Starter

Leclanché

Joined Nov 29, 2013
3
Thank you. I will give that a try. It will take a little time, but as Arnie says "I'll be back."

Sorry about the double posting :D Finger trouble!
 
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