Electronics problem, Help required.

[Mike Steward]

I would like to run my new Radio / CD Player from a separate timer partly as
bed side alarm and partly as a means to record programs when I'm out.

My multi function timer used to switch my old mains powered radio on by
simply switching on the mains supply, but with the new Radio / CD Player
the mains power has to be on all the time to maintain the tuning memory etc.

To switch the set on a simple click button is pressed which makes a pair of
contacts momentarily, just as a bell push would. to turn the set off the
button
is pressed once again.

My problem is how to make my timer simulate the pulse action. I have
connected a pair wires to the rear of the on/off button and need to be able
to
connect them briefly to turn the set on or off.

The timer switches mains. There is a ready 12 vdc within the set. I managed
to get the required affect by using 3 relays, 2 with 12 vdc coils, 1 with
240v
mains coil. But it seemed a rather clumsy way to go about it.

My question is: there another way possible with a switch.trasistor?
The two on/off switch contacts need to closed briefly when the mains comes
on and again when the mains goes off.

Sorry this explanation is a bit long winded, but to answer it one must
understand the
question.

Thank you Mike S.




---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.580 / Virus Database: 334 - Release Date: 15/11/2003

 

[ron doctors]

"Mike Steward" <flyer@freeuk.com> wrote in message news:<1077927869.10930.0@doris.uk.clara.net>...

I would like to run my new Radio / CD Player from a separate timer partly as
bed side alarm and partly as a means to record programs when I'm out.

My multi function timer used to switch my old mains powered radio on by
simply switching on the mains supply, but with the new Radio / CD Player
the mains power has to be on all the time to maintain the tuning memory etc.

To switch the set on a simple click button is pressed which makes a pair of
contacts momentarily, just as a bell push would. to turn the set off the
button
is pressed once again.

My problem is how to make my timer simulate the pulse action. I have
connected a pair wires to the rear of the on/off button and need to be able
to
connect them briefly to turn the set on or off.

The timer switches mains. There is a ready 12 vdc within the set. I managed
to get the required affect by using 3 relays, 2 with 12 vdc coils, 1 with
240v
mains coil. But it seemed a rather clumsy way to go about it.

My question is: there another way possible with a switch.trasistor?
The two on/off switch contacts need to closed briefly when the mains comes
on and again when the mains goes off.

Sorry this explanation is a bit long winded, but to answer it one must
understand the
question.

Thank you Mike S.

I would consider optoisolated switches they are very low cost and

simple tio use.
You can get them with either SCR , triac, or transistor ouputs. The
input is basically an IR LED . You can also get some that are neon
driven sop they can run directly off the line ( mains ). I like the
lED ones better . To runa LED
off the line you can use a capacitor to limit the current ot about 20
mA and diodes to remove the reverse flow.
ron

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.580 / Virus Database: 334 - Release Date: 15/11/2003