TA7317 protection board

[Original Burnedfingers]

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.

[d3imlay]

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$$.

[Original Burnedfingers]

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.

[pinkmouse]

Interesting. Would be nice to see a scalable design as I'm currently looking at building three five channel amps for HT use.

[Original Burnedfingers]

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..

[Original Burnedfingers]

My mistake The HA12002 crosses to a NTE1635 and this is a good number.

[Original Burnedfingers]

A circuit from the TOA service manual for series A903 MK II. A906 MK II, A912 MK II, and A924 MK II .

This is a bullet proof commercial amplifier and a good example of the HA12002 put to use.

[Original Burnedfingers]

Anyone have a schematic with a UPC1237 in it?

[msamkl]

...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.

[d3imlay]

Originally posted by msamkl
...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?