Mains power trip switch?

[PbR]

Hi,

I have my 2-ch music system, and tv connected, via a made-to-order extension, to the wall-plug, and am quite happy with such a power supply arrangement.
(this set-up was previously connected via a ups, but since the ups died, for reasons not related to the load, I had opted for direct connection)

The question I have:

Is there a switch/relay/trip mechanism such that when the mains power goes off, the input get cut, and remains cut when the power comes back, UNTIL it is MANUALLY (or via a timer) reset?

Cheers
PbR

 

[venkatcr]

Current electric circuits are fitted with a circuit breaker fuse system. If a fault develops, a switch is tripped. These trip switches are usually fitted near your fuse box, and near your electricity meter. When an fault occurs in the circuit, before blowing the fuse, these switches trip, meaning they move to 'Off' position cutting off power to your room and appliances. These trip switches are usually mechanical - this means that power is restored only when you re-set the switch to 'On' position manually.

Switches can trip for a number of reasons:

* An over loaded circuit - too many electrical appliances used at once
* A faulty appliance
* Shorting dues to water or leakage
* Faulty connections on appliance leads.

If a switch is tripped, unplug all the appliances. Set the switch to on position. Plug the appliance one by one till you locate the faulty appliance. When you connect a appliance and the switch trips again, that is the faulty appliance.

A image of a switch is shown below.

Cheers

 

[kaushik]

some ELNOVA Upss have that feature , i have a Elnova 500VA
it does the same !

if you want a low cost solution u can try the circuit attached !

kaushik

 

[SuhasG]

Hi,

I have my 2-ch music system, and tv connected, via a made-to-order extension, to the wall-plug, and am quite happy with such a power supply arrangement.
(this set-up was previously connected via a ups, but since the ups died, for reasons not related to the load, I had opted for direct connection)

The question I have:

Is there a switch/relay/trip mechanism such that when the mains power goes off, the input get cut, and remains cut when the power comes back, UNTIL it is MANUALLY (or via a timer) reset?

Cheers
PbR

I am not sure if any ready made Switch is available to offer this exact functionality. Check with people who do panel wiring, pump-motor dealers . What Venkat has shown is a Circuit braker its operation is different than what OP has asked for.

If no such device is available or found but expensive then a.A small electronic circuit can be designed to do this job.

A realy + simple driving circuit (with latch) (just a Transistor and couple of resitors) with Push button (momentary action) make it on and a simple DC power supply to power this circuit. This is called as a Latching relay circuit.

The Relay will actutally make / brake a big switch that in turn deliver / cut off powewr to . HiFI gear.

When you power up the set up. (Latching) Relay is in OFF state so the big Swich is also OFF means there is no power to your HiFI gear. Now you need to press the Push Button, Relay will be ON (and because it is latching type, will remain ON as long as power supply is there) that will make the big Switch ON and power will be delivered to your HiFI gear. Now if power fails and restores back, Relay though powered will return to default OFF position and unless you press the Push Button no power will be delivered to your Hifi gear.


I lost touch wiht electronic components market but such small gadget can be had for Rs 300-400.

Find any Electronic Hobbiyst or final year engineering (Electronics) student, s/he will built this circuit over a week end.

Hope this helps

SUhas

 

[PbR]

Switches can trip for a number of reasons:

* An over loaded circuit - too many electrical appliances used at once
* A faulty appliance
* Shorting dues to water or leakage
* Faulty connections on appliance leads.

Cheers

Thanks Venkat, I am aware of the circuit breaker switch, which trips on the above fault conditions. What I was looking for (as SuhasG) has pointed out, is a switch which trips at power-off, and requires a manual reset for power-on.

Cheers,
PbR

 

[PbR]

Thanks SUhas,

Yes this is exactly what I am looking for!

Some time ago, when I described such a device to a household electrician, he could not understand it (or perhaps my tamil!!), hence the query.

Cheers,
PbR

Hope this helps

SUhas

 

[PbR]

Thanks kaushik, let me see if my electrician can do this!!

PbR

if you want a low cost solution u can try the circuit attached !

kaushik

 

[awedeophile]

Thanks Venkat, I am aware of the circuit breaker switch, which trips on the above fault conditions. What I was looking for (as SuhasG) has pointed out, is a switch which trips at power-off, and requires a manual reset for power-on.

Cheers,
PbR

What're you looking for is a Motor Starter. Available with any industrial electrical store that sells motors, etc. Cost ~ Rs. 1000/-. Will switch off when the power goes and needs to be manually started. Some brands are BCH, Siemens & Telemecanique.

If you want something with a timer based reset, these are also available with or without high/low voltage cut off, etc. Products Main

 

[SuhasG]

some ELNOVA Upss have that feature , i have a Elnova 500VA
it does the same !

if you want a low cost solution u can try the circuit attached !

kaushik

Instead of 2 X 555 use 556 . It is 2 X 555 in one single package, more economical in terms of cost and PCB space.

 

[venkatcr]

Sorry PBR and everybody else on this thread. I seem to have misunderstood the requirement.

PBR you seem to have got the answers you want.

Cheers

 

[kaushik]

thank u PbR ,
yes as Suhas said 1 556 Ic should suffice! but 555 is 7Rs 556 may be 12Rs, so not tht big deal with 2 pieces of 555..verroboard 4X8cm will be 10Rs and should accommodate all the stuff except relay,which may be Mounted on the cabinet box.
For mass production of the unit 556IC will be economical.


Test your relay with the ckt , if it needs a higher current ,
1 transistor[BC 548] is needed to drive ,

see relay circuits with 555 on internet u will get that relay driver !



----------------------------------+ 9v
... ....................|
.......................||c
.......................||c Relay 9v
.......................||c
........................|
.......................|D| diode -> check online ckts
....................... |
from
pin3..27k.. b..../c
-|~~~~|----| BC 548
... ... ..... ..... . \e
..... ... ...... .... .|
...... ... ..... ... ._Gnd


in that case the pin 3 will go to a resistor,relay coil one end connects to collector and other +ve rail,emitter grounded.

 

[jacz]

Pls dont go for an electronic circuit for such a simple requirement. What you can do is buy a single phase contactor, connect the mains on one side and the load on the other side. Now feed power to the contactor through a N/O micro switch. Wire the contactor in such a way that the switch has to be pressed to get the circuit complete. Once the contactor gets activated use the same for completing the circuit..

This approach will eliminate the dependancy of having an electronic circuit which make things complicated.

 

[PbR]

Thanks to all who responded...It will keep me occupied for some time!!

Rgds