hello
i need a schematic that should turn on a relay when a signal is givent to it. i.e a small pulse of current. and turn it off when same signal is received

Thanks in advance

__________________
E = hf........ u sure?

 

Hi Raheem,

I have been thinking about just this circuit for a while now,
seeing your post has got me thinking about it some more.

I am trying to make a circuit to do exactly as you describe,
if i get it to work i will come back with the info.

I am thinking along the lines of one relay, one transistor,
and a few components.

Regards, John

 

I posted this schematic a couple of weeks ago. It might do what you need.

 

Hi Ron,

I had a look at that schematic you posted, and yes it is similar
to what i have in mind.

I was intending to use the type of relay that has a pair of C/O
(change-over) contacts, this is probably the most common contact
set found on small relays.

I had in mind to use one set to operate a transistor, and the other
set to be available for external use, isolated.

My mind keeps going round and round the ways of connecting the
transistor to the changeover set, and the ways of using the input
pulse ....

but i haven't done it yet.

I have convinced myself that it can be done with just a few
components (but i may be wrong ... )

If you happen to glimpse a possible way, please post it anyhow,
even if it is absurd, cos it might help me to think of a way.

Regards, John

Attached Images

RelaySwitch.jpg (11.2 KB, 185 views)

 

u guys are really helpful. Thanks Alot.

__________________
E = hf........ u sure?

 

Still looking at this.
Ive tried several circuits one of which involved having the relay
passing current in the on or off state, this i thought would be
unstable but it turned out to be ok and not subject to impact or
knocking as i thought it would be, but i still didnt like it,
i am now persuing a circuit which has no current through the relay
when its off, but needs a significant input pulse. This ongoing
attempt needs the input pulse to close the relay, however the second
pulse is through the transistor and doesnt need to be so big to
open the relay - thats if this circuit works ... a big 'if'

John

 

isn't this what you are actually looking four ?
http://www.electro-tech-online.com/viewtopic.php?t=2482
but since you only use one switch, you could use a 4013 flip flop, this way you just use the switch, the relay, the driving transistor, a resistor and a protection diode.

 

Sebi's posting in this forum on "On off circuit for doll house" looks like what you want. Just 2 gates, 2 R's and a cap. Let them drive a transistor to switch your relay.