TESORO GOLDEN SABRE

[Max]

Sinon,

Maybe Max means TS27m2, ST Micro Op-amp?

http://www.st.com/stonline/books/pdf/docs/2306.pdf

Molzar

Hi,
I meant 27m7, though 27m2 is good also for the purpose and really more easy to find.

Here's TI page of it:

http://focus.ti.com/docs/prod/folders/print/tlc27m7.html

though STM made it too, at least I think so.

Kind regards,
Max

[eclipse]

nope not enough place for 10 batteries ( i am using 9V housing which can hold up to 4 cells 1.2V each) do you think the lower voltage will be a big problem?
fully charged 8 batteries can give around 11.5V .. ( 8 X 1.44V) enough power for the speaker, i suppose. it will go down to (10V when they are discharged)
Google can search better than the forum search, argh
so i found that its discussed - ~30mA w/o sound ~60mA with sound

[simonbaker]

Today I made two battery packs - sizes like 9V battery,
consisting 4x1.2V NiMH, 750mA each pack, this will give me
around 11.5V-12V operating voltage fully charged. I will remove the 7808 and will place LM317 so I can adjust the output voltage (want to try with different voltages from 8V to 10V)

8 * 1.2 = 9.6, how get 12 v? Did you mean 5x1.2 packs?

Can anyone say what current TGSL draws normally?

Regards,

-SB

[eclipse]

Today I made two battery packs - sizes like 9V battery,
consisting 4x1.2V NiMH, 750mA each pack, this will give me
around 11.5V-12V operating voltage fully charged. I will remove the 7808 and will place LM317 so I can adjust the output voltage (want to try with different voltages from 8V to 10V)

[simonbaker]

Sinon,

Maybe Max means TS27m2, ST Micro Op-amp?

http://www.st.com/stonline/books/pdf/docs/2306.pdf

Molzar

Ah, thanks!

[simonbaker]

Actually simonbaker you are absolutely right for the 9V batteries!
There are NiMH GP batteries 200mA and i could find also 480mA ALCAXLINE (hard to get) LI ion. The difference in $ is big between those two but 200mA would not give more than 3 hours of work. Do you think i should remove 7808 in this case? Thus the device will drain the maximum power (~10V fully charged, and 7V discharged)?
And please if someone can, give more info on the resistors we mentionted here, can they be removed?
Cheers

I actually meant the 9.6 V battery packs for RC cars, etc. like this http://www.batteryspace.com/index.as...ROD&ProdID=776, should be good with low dropout voltage regulator like LM2941.

But interesting 9v battery is http://www.onlybatteries.com/showite...t1=14&uid=1970 because it is real 9 volts, 400 mAh. A little bigger size than normal though. I would like to use with my Compadre but probably won't fit miserly compartment. Like Max says a little wimpy for TGSL but interesting to try anyway -- I would use with LM2941 and try running TGSL at 7.5 volts, use thicker wire for TX coil to save power.

-SB

[Molzar]

Sinon,

Maybe Max means TS27m2, ST Micro Op-amp?

http://www.st.com/stonline/books/pdf/docs/2306.pdf

Molzar

[simonbaker]

Hi,
1. it's not lock-in amplifier, you haven't critical integration there, but it's similar cause you mix reference and input signal of same frequency, then filter with a low pass: this filters out many noises but not very good... that's why you can get interferences in TGS from power lines, switching regulators etc. LF353 is a sensitive one... hi bandwidth. Can use different but seems it's good choice having one there instead of other stuff.

2. LM358 : uhm... is old good... but not so good, good replacements are possible and suggested... lower noise like TS27m7, they work better than LM358

3. LM308 : replacement possible... but worth ? I think not at now. Seems metal LM308 are the best there, for now.

4. LM393 : can replace but change few cause source of noise is not there, but early in the chain

5. TL062, avoid them at all. Use lower noise, even TL072 is fairly better.

Kind regards,
Max

Thanks that is helpful -- TS27m7 no found on google, but found LT1057 mentioned in same thread message, looks good too. This thread is like a book, needs an index!

Regards,
SB

P.S. J107 switches look like switching mixer of lock-in amp to me, but maybe we use different definitions.

[Max]

I draw what I mean, do you think this is going to work?

Hi,
will work, even if I don't understand why using RH output stage there ?

It's good if you wanna exclude output influence on stability... cause filters better noise due to that part of circuit when using the speaker.

But you can do also on TGSL using the monostable mod...

Anyway, try it and let us know.

Kind regards,
Max

[Max]

Would greatly appreciate if someone would comment on why each op amp chosen for its stage.

Some guesses:

LF353 - low noise high bandwidth, basically a preamp for the J107 lock-in amplifier to boost everything from the RX coil with as little noise and distortion as possible.

LM358 - just a cost effective, good old workhorse efficient op amp, high gain, bandwith not so important because part of low-pass filtering? Why not ultra-low noise for this also?

LM308 - precision op amp to provide very accurate gain relative to ground (because of very low offsets) of phase signals prior to comparing by the LM393. Is precision more important than low noise in this stage?

People tried substitutes that didn't work as well -- can they explain the reason?

Understanding reasons for each choice would help in finding substitutes.

Regards,

-SB

Hi,
1. it's not lock-in amplifier, you haven't critical integration there, but it's similar cause you mix reference and input signal of same frequency, then filter with a low pass: this filters out many noises but not very good... that's why you can get interferences in TGS from power lines, switching regulators etc. LF353 is a sensitive one... hi bandwidth. Can use different but seems it's good choice having one there instead of other stuff.

2. LM358 : uhm... is old good... but not so good, good replacements are possible and suggested... lower noise like TS27m7, they work better than LM358

3. LM308 : replacement possible... but worth ? I think not at now. Seems metal LM308 are the best there, for now.

4. LM393 : can replace but change few cause source of noise is not there, but early in the chain

5. TL062, avoid them at all. Use lower noise, even TL072 is fairly better.

Kind regards,
Max

[Max]

Actually simonbaker you are absolutely right for the 9V batteries!
There are NiMH GP batteries 200mA and i could find also 480mA ALCAXLINE (hard to get) LI ion. The difference in $ is big between those two but 200mA would not give more than 3 hours of work. Do you think i should remove 7808 in this case? Thus the device will drain the maximum power (~10V fully charged, and 7V discharged)?
And please if someone can, give more info on the resistors we mentionted here, can they be removed?
Cheers

Hi,
9V battery on TGS ? No good. Will last few, expecially on the speaker.

IF you mean on TGSL (smaller circuit, smaller consumption) it could be good... but you'll get lowered audio cause audio stage runs on battery voltage... so the more you have, the more it sounds strong.

In TGSL with headphones you can use 9V battery... but just using a very low dropout 8V regulator instead of 7808 (that requires at least 11V on input to work good).

A 9V alkaline (e.g. duracell's one) could last also 15hours if device is used on headphones only. This is similar choice to bandidoII strategy... use headphones and battery will last also 20hours in bandidoII, for real (this is also due to lowered consumption of bandidoII components).

NiMh of small capacity must be avoided on TGS/TGSL... 200mha are not enough for decent performances and duty. Better something around (at least) 500mah.

Kind regards,
Max

[eclipse]

I draw what I mean, do you think this is going to work?

[DIRCEU]

Hi! ALL

Recently I bought 20 pieces of uA 308N (metalic).
Have anyone some info if compared with LM 308 AH (metalic)???
Thanks in advance

DIRCEU

[simonbaker]

Would greatly appreciate if someone would comment on why each op amp chosen for its stage.

Some guesses:

LF353 - low noise high bandwidth, basically a preamp for the J107 lock-in amplifier to boost everything from the RX coil with as little noise and distortion as possible.

LM358 - just a cost effective, good old workhorse efficient op amp, high gain, bandwith not so important because part of low-pass filtering? Why not ultra-low noise for this also?

LM308 - precision op amp to provide very accurate gain relative to ground (because of very low offsets) of phase signals prior to comparing by the LM393. Is precision more important than low noise in this stage?

People tried substitutes that didn't work as well -- can they explain the reason?

Understanding reasons for each choice would help in finding substitutes.

Regards,

-SB

[eclipse]

Actually simonbaker you are absolutely right for the 9V batteries!
There are NiMH GP batteries 200mA and i could find also 480mA ALCAXLINE (hard to get) LI ion. The difference in $ is big between those two but 200mA would not give more than 3 hours of work. Do you think i should remove 7808 in this case? Thus the device will drain the maximum power (~10V fully charged, and 7V discharged)?
And please if someone can, give more info on the resistors we mentionted here, can they be removed?
Cheers