AB100 Class AB Power Amplifier

well .. i am rather sad looking at a schematic like that ....World wide demand of TIP 142-147 will raise like hell again ..

I also find it very sad that in many of TIP 142-147 specs there is no audio specs which is rather expected since TIP 142-147 is low freq switching application or better elevator transistor to drive the solenoid that locks the door

I also find very strange that internals of a TIP 142-147 vary from manufacturer to manufacturer and often from batch to another with the relation between the driver and the output undefined or unknown which will result that the specific transistor will behave in a different way when it comes to beta and thermals ....

Yet again in my trivial about darlingtons i said very clearly that i have never seen an amplifier that uses parallel darlingtons except the NP A40 which to my gestimation it doesn't fall in oscillation since darlingtons are way too busy with the bias .

Thermals should be some issue in your design i think and implementation by DIYers will bring up issues ..

One more thing will be that when it comes to design something it will be wrong to work on semis that already have been cannibalized by plenty of bad /second/third manufacturers ...When people like me that repair 400-500 amps per year often need to find any possible transistor existing to maintain specs ...Ask me where you can get real TIP 142-147 and the answer will be i don't know !!!

I fall from the clouds ..... i was really expecting a lot more in this field from the one and only ....

Kind regards
sakis
 
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hi,

I just did AB100 simulation in LT SPICE (with MPSA instead ZTX and BD instead SC/SA), feedback resistor increased to 20K = input 1V; output 16V . DC offset low, THD about 0.01%. 50V rails.
looks good to me (I am not an expert in spice)
tnx NP. maybe someone stronger in Eagle or other software can draw some layout >?
 

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TI was the originator of the TIP series of power transistoer (back when they still made them). ON semiconductor, ST and Fairchild are still good suppliers, so supply is not really an issue. Keep in mind that Fairchild does a couple of package variations of the part, one in a standard TO3P package and another version looking similar to a TO-247, but requiring an M3 screw for mounting. This is a PITA for us US types, but a plus is that that package doesnt require a shoulder washer, unlike the TO3P

There is also nothing stopping one from using TO-3 devices like the 2N6283 and 2N2287 for output devices - ON semi still makes them, and Digi-key stocks them...
 

6L6

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its works fine even with 24V rails and you can bias it for 1A and adjust gain.

Does it work at 60v rails?

I have a couple of transformers I would love to use...



wrenchone said:
Keep in mind that Fairchild does a couple of package variations of the part, one in a standard TO3P package and another version looking similar to a TO-247, but requiring an M3 screw for mounting. This is a PITA for us US types, but a plus is that that package doesnt require a shoulder washer, unlike the TO3P

This datasheet from Mouser shows that the package is a TO-247 http://www.mouser.com/ds/2/389/CD00000914-20927.pdf

I mention this not to be argumentative in any way, merely to show that we might not need to deal with a weird package. :) :) :)

There is also nothing stopping one from using TO-3 devices like the 2N6283 and 2N2287 for output devices - ON semi still makes them, and Digi-key stocks them...

Nice! Are those intended replacements, or just extremely similar?

Also, is there a different suitable transistor to use in place of the 2SA1110 and 2SC2590?
 
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The one and only
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Also, is there a different suitable transistor to use in place of the 2SA1110 and 2SC2590?

I don't know, as I pay little attention to what's out there in Bipolars these
days (that said, we just made a 10 year buy on the closeout of some
Toshiba's).

Those parts were chosen because I had stock courtesy of the boys at Adcom
and knew that the probable OEM used them.

:cool:
 
A big thank you Nelson for this gift :)

This amp looks reliable and quite CHEAP to build :)))

this would be a good example of a polite responce.

notice the thankyou for somthing we where given, and after a complment was given.

i would like to echo this and, remind those that perhaps forgot that this was somthing that nelson would have made money from and was given to us free.

the impolite thing to do would be to express dissapointment. in either the pick of topolagy, devices, or the color of boxers he had on when he drew up the blue prints.........
 
As for the Fairchilld "TO-247" part, you have to be careful - Mouser is not always accurate. A real TO-247 part will take a 6-32 mounting screw - the Fairchild parts I encountered will not, even though they look superficially like a std TO-247. Then again, maybe there are 3 versions out there - TO3-P (requires insulating shoulder washer), real TO-247 (no washer, 6-32 mtg), and "TO-247 variant" which needs an M3 screw. Of course, an M3 will work on both the TO-247 and the variant, but I'm in the US of A, where metric screws, though available, are still kinda weird. IXYS also has some parts in the variant case.
 
Maybe the vendors are consolidating package types, as the real TO-3P parts were always kinda weird, and TO-220/TO-247 is the de facto standard for power devices these days. They can do this, as well as monkey with other parameters, as the TIP parts were not registered with JEDEC.

All the old On Semi and ST parts (and of course, TI) I have are TO-3P. The Fairchild data sheet I accessed shows a hole that will just barely clear an M3 screw. Of course, an M3 screw will work with the Fairchild part as well as a std TO-247.

P.S. I hate tapping M3 holes...
 
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