speaker protect schema here

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tadiam

Member
2007-03-01 7:33 pm
I build this the last week and work well.....this detect +/- tension.
I use one circuit for each channel and idividual relay...
 

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No offence, but the upc1237 chips are less than a dollar,
will detect AC loss, as well as DC offset... All it needs is about 5 resistors 3 small electrolytics, 2 diodes, and a small film or ceramic cap. can be used with as many channels as you like as long as they are powered by the same PSU... as it samples AC before the rectifier and DC after it...

Better yet, it needs no dedicated power supply like your 12V rail, it powers itself through the senseing wires... can be used on amps from 25 to 60VDC.
 
As you know i am in South America... despite we are not too much delayed

I have to explain you dear Nordic, to inform you the differences we have, related development, compared to other more modern countries, we use shops to buy those things....of course... i am talking about Brasil...and i could perceive those things are changing and fast.

And even the bigger ones, the big shops, have not complete line of chips.

The transistorized option, even beeing worst, is an option to us that have not the easy way to buy those things.

We cannot order by mail.... in my place customs block those things saying it is an imported good subjected to taxation... sometimes they block and ask your presence into the Mail department..sometimes your parts just disappear without left track.

So...we do not use internet to order things, in such a confortable way., sitted in front our computer.. we move our.... our..... our bodies to downtown... we spend gasoline (4 bucks!), we pay parking place (one more buck!), we walk as a hell, we go to the streets were the electronic shops are... we enter strips...we ask for the unit and the salesman answer you.

- "UPC we have 1221 and 1225...but we do not have the one you ask...i will take note of that and soon (6 monthes of new importation period of time...and if the shop owner perceive many folks asking for the same part number) we will have that part for you."

To assemble with transistors we can do those things easier... i am also searching for a complete schematic..but i want off set sensor.. also o would like to adjust the time delay to enter the speaker... would like to have monitoring leds to show me the circuit operation and so on.

I do not know, exactly, what happens in Argentina...but as we are neighboors...it is possible that happens the same way.

regards,

Carlos
 

tadiam

Member
2007-03-01 7:33 pm
Ok in argentina happen the same...have good parts at hight prices and normal (fakes) at normal prices.
The stores sales the normal components...have specials parts but your need import this and yours prices are higth (in most cases the salesman no know the conponent)

I need make amps or circuits at normal and easy find parts no rare....maybe the upc are best but here make "for necessity" easy find parts components and circuits...

Carlos..build the dx..work well at my ls70 speakers....but the search continue......
 
As much as I agree with Nordic about the superiority of chip-based solutions it’s always nice to see examples of how discrete circuits accomplishing the same things are put together. After all, if no one would pass on this know-how there eventually wouldn’t be people left to design the chips in the first place.

Could someone perhaps present some simple ideas of how this circuit could be modified to house features such as a fault indicator LED and the aforementioned AC loss detector?

And I can totally relate to Carlos and Tadiam: Around where I live all these ICs that have some kind of a special function are rarities in local component shops and if you have to order them they become quite an expensive solution. ...Assuming the ordering is even an option. I was under the impression that they discontinued manufacturing of uPC1237 anyway?
 
Into the present moment, it is not my priority to study this subject, but

near future i will search for or develop a discrete protection with all features.... i think i am able to do that... at least i can try.

Fully agreement Temuk..... hard to find parts..... well..... i do not love too much those chips....black boxes.... we do not know what is inside...i felt discrete more kind, more interesting, more romantic...well.... i prefer discrete...maybe because i am an old folk.... from the transistor era..... i was able to have the first transistorized radio.... was very interesting those days.

People say the transistor was not human discovery... that was found into an Unindentified Flying Object (UFO) , an outside earth aircraft that fell down in Roswell, down the fifties.... i do not know exactly, but make a lot of sense...also laser and some material bullet resistant too..metals with memory of shape... those things.

Of course we are not alone in this enormous Universe...no chance to be alone!

regards,

Carlos

.......................................................................................................

Of course i want dear Nordic

But also i do not want you to spend more money sending me things... you have already made a lot of those things to me.... you have sent me some heatschrink material and Field Effect Transistors..... mail to Brasil is not cheap....because of that, with my thanks because your kindness, i decline your kind offer.

regards,

Carlos
 
UPC1237HA(MS) Discontinued 04/1997
UPC1237HA Phase-out 04/2008
UPC1237C Limited production

http://www.necel.com/nesdis/image/IEP-730A.pdf
Look at page 4

protect.gif


Pin2 senses DC offset.
pin 3 is connected to ground or to ground via a cap to form a latching protection.
pin4 sences ac off through a diode and resistor
pin5 connects to ground
pin6 drives relay through a resistor, the other side of the relay connects to DC+ supply
pin7 connects to pin8 with external 56k resistor and has 33uf cap to ground

protect2.gif
 

RSK

Member
2004-11-20 3:03 pm
K.L.
Speaker DC protector

This I have constructed and works very well.
No need for additional transformer.
R1 & R2 can be configured for various voltage from +25V to +70V
Includes AC detect for delay turn on and off for speaker.

Cheers.........Raj
 

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RSK

Member
2004-11-20 3:03 pm
K.L.
Hello Carlos / Nrik

The circuit is by Siliconchip magazine issue July 2007 under 20W class A amp.
Please get it as I cannot post it here.

Carlos, I will send you the image of construction. Please post it here as I do not know how to load here. The image is too big.

Working very well. Tested with 1.5V dc input and it works good.

Cheers...............Raj.
 

Greg Erskine

Member
Paid Member
2002-01-05 11:56 pm
Sydney
Re: Hello Carlos / Nrik

RSK said:
The circuit is by Siliconchip magazine issue July 2007 under 20W class A amp.
Please get it as I cannot post it here.

Carlos, I will send you the image of construction. Please post it here as I do not know how to load here. The image is too big.

Working very well. Tested with 1.5V dc input and it works good.

Cheers...............Raj.

Hi RSK,

You can post the schematic, as long as it the one you have drawn and not an actual scan of the SiliconChip article. The circuit is not copyright but the publication, pictures are.

Carlos already has the complete set of the Silicon Chip 20 watt class A articles.

regards
 
Here is RAJ construction of the Silicon Chip magazine protection

I cannot post the circuit.... it has copyrigth.

RAJ boards are good, made at home.

RAJ have already offered to produce boards for friends, at very reduced price, almost the cost to produce the boards plus mail costs.... he can enter as the provider of boards to some small group buy we organize.

Was offered some monthes ago.... now a days we have to contact him in advance and arrange those things.

He do not use silk screen over the boards.... they are made at home but really professional work.

RAJ do not need to own money from forum, he has a very confortable life in his country... his intention, when have offered, was the cooperation only..i ensure you that.

regards,

Carlos
 

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