TA7317 protection board

Is there anything available to purchase like the attached schematic? Would anyone consider this to be of any value for a possible group buy?

I would think that this would provide the necessary protection for our prized speakers.
 

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I believe I've seen protection circuits with the IC's you mentioned.
The TA7317 has had a long run in many amplifiers and has a good track record. It is still available from MCM and other dealers at a low price usually around $2 a pop.

The partial schematic I put up is from a ALtec 9442 power amplifier. The only weakness being the timing cap, resistor, and diode shown in yellow. When a higher voltage cap is used it will extend the life of the circuit.

It would be nice to generate interest in a protection board. I currently use a Velleman 4700 to protect my speakers when I use a chip amp,tube amp, or any amplifier without a protection circuit.
Its cheap protection against frying a driver. While the 4700 can be had for less than $40 without shipping it might be nice to have a cheaper diy project that can be put together for less than 1/2 of the cost of a 4700 kit.
 
I've been looking at this chip along with the Ha12002 and upc1237. There is an NTE equivalent also. They're readily available in the US and only cost a few$$.

The HA1202 is a common protection IC in amplifiers like TOA and many others. Unfortunately they do show a cross to a ECG1041 which crosses to a NTE part number that is shown to be a FM IF AMP clearly not a good cross.

The UPC 1237 crosses to a NTE7100.

Surely money could be saved by looking at the TA7317 part over the NTE part. Just my opinion..
 

msamkl

Member
2005-11-28 9:13 am
Athens
Hi, this schematic is published...

...in the webstore www.diyclub.biz ;) I hope that will do the job. I'm also interested in such a protection board as this could be a great addition to my 2 beloved amplifiers, but I don't have the experience nor the knowledge to give it a try. If you end up to a schematic with a PCB draw, I'll be very interested in. I think there is no need to be for the uPC1237;I think all those IC's (HA12002, TA7317, uPC1237 etc.) have the same characteristics and pin layout.

Regards,
Thanasis.:)
 

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d3imlay

Member
2004-09-09 11:34 pm
Ohio
Re: Hi, this schematic is published...

msamkl said:
...I think all those IC's (HA12002, TA7317, uPC1237 etc.) have the same characteristics and pin layout.

Regards,
Thanasis.:)

Unfortunately, none of them have the same pinout. The TA7317 is a 9 pin versus 8 for the other two. The advantage of the TA7317 is it has two inputs, whereas the other two have one input. On these you can sum two channels through input resistors. I like the upc1237 because it is widely available. Like the HA12002, the output can be latched off when it trips.

As far as relays go, there is an article in AudioXpress in the August 1992 edition. Does anybody have a copy?
 
Unfortunately, none of them have the same pinout. The TA7317 is a 9 pin versus 8 for the other two. The advantage of the TA7317 is it has two inputs, whereas the other two have one input. On these you can sum two channels through input resistors. I like the upc1237 because it is widely available. Like the HA12002, the output can be latched off when it trips.

d3imlay is correct. The pin out is different in all three chips.

Is it important to be able to latch off the output if the relay trips? I've never come across that in a unit yet. That pin was always tied to ground to allow an automatic reset when conditions changed.



Personally I like the two individual input of the TA7317 IC.