TESORO GOLDEN SABRE

[ivconic]

Quiaozhi many thanks for that link!!! Wow! Excellent explanation! Thanks much!

"...The most common supercapacitor applications are memory backup and standby power. In some special applications, the supercapacitor can be used as a direct replacement of the electrochemical battery. Additional uses are filtering and smoothing of pulsed load currents. A supercapacitor can, for example, improve the current handling of a battery. During low load current, the battery charges the supercapacitor. The stored energy then kicks in when a high load current is requested. This enhances the battery's performance, prolongs the runtime and even extends the longevity of the battery..."

So...this just justify my previous presumtion! It will turn that my question is not stupid at all!

[ivconic]

Yes Quiaozhi, that's the component! I have almost identical here by me.
Acts indeed like real capacitor!
So, i was thinking to wire it up at TGSL and observe behavior on scope. First i would like to wire it up at chopper output. Usually it produces -6.2V +/- 0.5V. So.... hopefully this special capacitor will further stabilize and filter negative rail at TGSL. Will try and see later..
Also, it would be good to wire it up to TX supply also.
Need to be checked.

[Qiaozhi]

Hi Qiozhi
It isn’t new innovation.
Best regards.

It seems you are correct. I read somewhere that it was accidentally invented in the 1950s.

I guess I never realised that these small memory backup devices were actually supercapacitors.

There's some info here -> http://e-articles.info/e/a/title/Adv...upercapacitor/
that describes it as a cross between a normal capacitor and a battery.

[Max]

I use hte PWB design attached in the first message of this thread. The bipolar capacitors are constructed of two 10u electrolytics in series, minus poles connected together.

The current consumption is 60mA. Is that correct?

There are 20mV ripple at 700kHz on the +8V rail, riding on 20mV ripple at the transmitter's frequency. How clean did you get that?

I have tried bypassing the 8V regulators in/output with 100n and the same for the PNP transistor's emitter of the negative voltage generator. No help.

I disconnected the 470n cap from pin 1 of the amp, that didn't help. Disconneting the 100k resistor from pin 3 did nelp a bit. I have a feeling, that the power rails should be cleaned before trying anything else. I can find ripple everywhere in the device, just can't find the source. Could the ripple be born somewhere else and it jsut get's amplified by the amp in question?

Andy
I have tried bypassing the

Hi,
the 60mA you read are a bit high but , depending on op amps you use, could be ok.
If you notice 130mA consumption when no sound there's a problem for sure, and you probably burnt the op amp that likely self-oscillate.

The ripple amplification is unavoidable in such designs, so the strategy is to keep noise low from start, avoid ground loops, filter any sensitive power line/rail etc anything you can do to keep noise as low as possible is fine.

I suggest you try 100nF directly at op amp site, on pads of power rails of it, then to gnd rail. That will filter out many spurious noise from it... but also, if you use hi CMRR devices you'll be shielded enough from that problems.

The 700Khz ripple is anything but good, so try these strategies described above to make it vanish if you can. The original board is not perfect but has been realized by many people here, including me with success so, can't be the board design for itself but other factors like e.g. rosin from solder wire etc you must clean it very well with e.g. isopropilic alcol or similar stuff (solvents).

Also, the voltage regulator can be a source of that noises... if have different ones try another and look for differences, could help too.

Kind regards,
Max

[Qiaozhi]

please dear max,ivconic,qiazoni ,simonbaker

Can some one tell what i am doing here?

I don't know!
I give up ... what are you doing here?

[aft_72005]

Hi Ivconic,

Is this it? -> http://www.bikudo.com/product_search...capacitor.html

You said you had seen these in old VCRs, but I thought super capacitors were a relatively new innovation.

Hi Qiozhi
It isn’t new innovation.
Best regards.

hi

please dear max,ivconic,qiazoni ,simonbaker

Can some one tell what i am doing here?

[Qiaozhi]

Hi Ivconic,

Is this it? -> http://www.bikudo.com/product_search...capacitor.html

You said you had seen these in old VCRs, but I thought super capacitors were a relatively new innovation.

[metaldetector107]

TGSL

Dea Qiaozhi MAX Ivco
please how to measure RX frequency without capa and coil calculation
i mean with digital multimeter which has got frequency meter as well
thanks

[aft_72005]

Now is my turn to ask funny question;
have you ever noticed that capacitor-look-like component, usually present in older VCR's? Small component, exactly capacitor look, usually labeled as 0.47F (!!!!) 5V or 6V? Meaning actually 47 000 uF !!! Small...smaller than capacitors we are using mostly here.
So.. i took one recently and wired it parallel with one led diode and ps. Switched on ps and second after switched off. Led diode shined (diming down) for 2 minutes after!!!!!
So...actually it is capacitor. Hell of capacitor! Excellent to stabilize some voltage. So...here is my funny question:
How about, if we use that component(s) in TGSL? On very few places, especially on TX and eventually at chopper output (reversed, respecting polarities there)....ha?!
I asume, it will take a bit of time to charge fully from accu. So, after switching on, detector will be ready to operate after few seconds...
I never had any experiences before with this kind of capacitors....but shure this look like having some potentials to be used here...
I am very interested in your opinion..

Hi ivconic
Yes , it is 0.47F or 470000 microfarad . I saw it at motherboard of pc.
It is usually use instead of backup battery .
May be in your old VCR did use for memory saving and real time clock .
Best regards.

[Qiaozhi]

Now is my turn to ask funny question;
have you ever noticed that capacitor-look-like component, usually present in older VCR's? Small component, exactly capacitor look, usually labeled as 0.47F (!!!!) 5V or 6V? Meaning actually 47 000 uF !!! Small...smaller than capacitors we are using mostly here.

This sounds like an unusual component. Are you sure it has this huge value of capacitance?
Do you have a photo?

[ivconic]

Now is my turn to ask funny question;
have you ever noticed that capacitor-look-like component, usually present in older VCR's? Small component, exactly capacitor look, usually labeled as 0.47F (!!!!) 5V or 6V? Meaning actually 47 000 uF !!! Small...smaller than capacitors we are using mostly here.
So.. i took one recently and wired it parallel with one led diode and ps. Switched on ps and second after switched off. Led diode shined (diming down) for 2 minutes after!!!!!
So...actually it is capacitor. Hell of capacitor! Excellent to stabilize some voltage. So...here is my funny question:
How about, if we use that component(s) in TGSL? On very few places, especially on TX and eventually at chopper output (reversed, respecting polarities there)....ha?!
I asume, it will take a bit of time to charge fully from accu. So, after switching on, detector will be ready to operate after few seconds...
I never had any experiences before with this kind of capacitors....but shure this look like having some potentials to be used here...
I am very interested in your opinion..

[simonbaker]

I use hte PWB design attached in the first message of this thread. The bipolar capacitors are constructed of two 10u electrolytics in series, minus poles connected together.

The current consumption is 60mA. Is that correct?

There are 20mV ripple at 700kHz on the +8V rail, riding on 20mV ripple at the transmitter's frequency. How clean did you get that?

I have tried bypassing the 8V regulators in/output with 100n and the same for the PNP transistor's emitter of the negative voltage generator. No help.

I disconnected the 470n cap from pin 1 of the amp, that didn't help. Disconneting the 100k resistor from pin 3 did nelp a bit. I have a feeling, that the power rails should be cleaned before trying anything else. I can find ripple everywhere in the device, just can't find the source. Could the ripple be born somewhere else and it jsut get's amplified by the amp in question?

Andy
I have tried bypassing the

You have made the full TGS version which I think has notch circuit, so 60 mA probably OK - TGSL (lite) version has no notch circuit and uses about 30 to 40 mA I think.

Question: is the 700 kHz ripple in phase with the TX signal? In other words, if you trigger your oscilloscope on the TX signal, is the ripple stationary or does it run freely over the TX signal like a blur?

I get big spikes on my supply rails, but they are at the switching frequency of the negative supply push-pull transistors. They are in sync with the TX signal, so hopefully create a constant offset, not noise.

If the ripple is from some other place, I would think you would see it also in the other half of the op amp.

Try putting a jumper wire from pin 1 (output) to pin 2 (inverting input) of the LM358 and see what happens. If that amp is oscillating, it should change it.

A bad feedback capacitor with lots of inductance could cause oscillation in any of those op amps. Go to each op amp and jumper the output to inverting input and see if the oscillation stops anywhere.

Just some ideas...

Regards,

-SB

[simonbaker]

?????????!!!
Please, just look up; Simonbaker just posted it!

Yes, a few messages before this one. Here is the link: http://www.geotech1.com/forums/showp...postcount=3409

It is the top picture you want to look at, showing the cable wires attached to the coils and shield. What isn't shown is that the black wire of the RX cable goes to the inverting (-) input of of the op amp in the RX circuit.

Regards,

-SB

[ivconic]

Dear Ivconic????
i am sorry but i am realy confused
i know you dont like repeating question
but this time please dont
could u tel me the thread page of your coil wiring
if u cant remeber please trouble yourself and make another one for me
you it is realy good favor;;
beacuse i know i made mistake like till your last reply to me i was connected both
shield to PCB but still any slight movement sounds
abou the cable I am using a PI metal detector cable called P-158
the cable has two pairs of wire and each pair has its own shield
many many thanks
by the way iam not lazy i have downloaded all 137 pages of TGSL
abd reading them daily but still i am hopless with you and MAX and other gentlments

?????????!!!
Please, just look up; Simonbaker just posted it!