IGSL

[ivconic]

Hi Ivconic and SilverDog,

firstly many thanks Ivconic for the recent recommendations to reduce gain slightly, I think that will help my machine quite a bit, though its going to take a week or so to get hold of the parts needed as I don't have them to hand.....

I have another question for you and SD, I would be grateful for both of your opinions:-

I have looked at the schematic and it appears that the input 12 volts from the battery is only used (unregulated) for driving the loudspeaker, otherwise it just supplies the 8 volt regulator. Am I correct?

Now would the loudspeaker take 18 volts at that point (SilverDog, what are the specs of the little loudspeaker you supplied in the kit?) as I am looking at two good 18v rechargeable battery packs and of course the charger that I have left over from a battery drill with a burnt out motor that I was given, almost new......

I could put in a bigger value resistor to drop the voltage instead of the 330 ohm (R69), but if I can get the loudspeaker louder instead, that would be great!!

I am also thinking of cutting off the whole handle of the drill and eventually attaching it to my MD (high up for a better balance) so that the batteries can be plugged in from outside of the machine once charged......might look quite good as well!!

Maybe such rechargeable drills, that can be bought very cheaply, could be a good source of batteries, charger and socket.......even when bought new.....I saw one today for around $20 (€15). Individual batteries (2 sets), battery holder and charger etc., would cost more I feel.....of course a broken drill is even cheaper....

Thanks in advance to you both for your thoughts and ideas.

Regards

Andy

I think audio part should hold 18v there. Give it a try with bench supply before you buy batteries.

[der_fisherman]

I think audio part should hold 18v there. Give it a try with bench supply before you buy batteries.

I got given the batteries and the charger for nothing!
Can't get cheaper than that!!!
Regards
Andy

[Amalio]

Bernte that's good for now.
Coil must be more precise balanced.
Those small chatters that appears from time to time are caused by increased gain at channels.
For now you just do make small changes and return values as noted on sketch bellow.
Instead 1M5 put 470k and instead 10nF put 22nF, on all places noted on sketch.
That's how you will void those chatters and instability.
I wanted to experiment with higher gain than and later realized that it was bad idea.
So, when you return values like those are at TGSL, you will not have chatters and instability and therefore will be able to balance coil more easily.
Cheers!

Hello Ivconic

talking about changes, R7 and R8 5K1 more?

worth changing?

greetings

[golfnut]

Jerry, Im with you on the battery mass.

On my IGSL, I have a remote battery and a miniture power socket on the front panel.


The 3 Lithium ions I robbed from a duff laptop battery from work,.

If you cut the pack there will be a dying cell - easily id when you separate all of the cells out. Often 6 arranged 2 in parallel - three times.

Anyway, do three in series to get 12v 1800mAH

To charge I got a £5 charger/balancer from Giant Cod.

You also need a plug and flying lead to charge - it will have 4 wires - one + , - , and the cell junctions.

I use pvc heatshrink to get a 'Pack', plus 2 foot of flying lead - sorted.
The charge lead pokes out of the heatshrink for charging.

I will arrange a pic if any takers
Steve

[Jerry]

Jerry, Im with you on the battery mass.

On my IGSL, I have a remote battery and a miniture power socket on the front panel.


The 3 Lithium ions I robbed from a duff laptop battery from work,.

If you cut the pack there will be a dying cell - easily id when you separate all of the cells out. Often 6 arranged 2 in parallel - three times.

Anyway, do three in series to get 12v 1800mAH

To charge I got a £5 charger/balancer from Giant Cod.

You also need a plug and flying lead to charge - it will have 4 wires - one + , - , and the cell junctions.

I use pvc heatshrink to get a 'Pack', plus 2 foot of flying lead - sorted.
The charge lead pokes out of the heatshrink for charging.

I will arrange a pic if any takers
Steve

Good idea! I just happen to have several of old laptops with dead batteries.

On TGSL is use two 9 volt in series however for IGSL I think a different approach is needed.

Jerry

[ivconic]

Hello Ivconic

talking about changes, R7 and R8 5K1 more?

worth changing?

greetings

I think not.
Anyway; you can change those if you like and see if there are differences.

[Amalio]

I think not.
Anyway; you can change those if you like and see if there are differences.

I'm changing capacitors and resistors in the discrimination of my modules IGLS musketeer, and see results first.

maybe later try 5K1 resistors

greetings

[bernte_one]

for andy

yes unshielded coil i use it every time for first testing only

for all
at the moment i use ten eneloop 1,2v batterie pack it is placed near elbow stem perfect balanced for more hungry units like pi´s i use three or four 18650 in serie (12 or 16V)

more threads

power
http://www.geotech1.com/forums/showthread.php?t=17810

stem
http://www.geotech1.com/forums/showthread.php?t=17958

regards

[der_fisherman]

Hi bernte_one,

many thanks for your post, most interesting and informative, it will help me to finish my MD over the next few weeks.

regards

Andy

[golfnut]

I may need to tweak ground balance - on the fly on hols tomorrow.


As you look at the pcb osc is top left power reg is top right

which trimmers do this?

Please tell me location or sketch - No numbers pls

I cant read the silkscreen - as parts obscure them.

Steve

[golfnut]

Any takers with my last post - Im going in a couple of hours...

[silverdog]

IGSL

sorry, missed this one earlier

Ground Balance trimmers are Tr1, Tr2, left hand side above LF351

[ivconic]

I may need to tweak ground balance - on the fly on hols tomorrow.


As you look at the pcb osc is top left power reg is top right

which trimmers do this?

Please tell me location or sketch - No numbers pls

I cant read the silkscreen - as parts obscure them.

Steve

...

[bernte_one]

Quote:
Originally Posted by golfnut
what was wrong?

I used pin 1 of ic U1a - output of receive pre-amp


The amp has a gain ~50 so if you see 800mv you got it about right.

Steve



has made a first test with my first usb scope ever and could set the coil down to 90mv with a good sinus signal - wasn´t able to do that with my multimeter

but coil is unshielded and the higher gain parts are still on pcb
need some sleep now
next work on igsl in some hours...
00:26 in germany now
good night

[der_fisherman]

High and Low Tones from IGSL, whch ones?

Hi Ivconic,

in reply to your recent excellent diagram about the workings of the two trimmers TR1 and 2, do please remember that the tones "High & Low" may not be the same way round as you have made them on your machine, on ours, as there was no indication (that I remember anyway!) from anyone as to what to use where.

So either we (you?) set a standard (which I personally would prefer from you yourself, as it makes it far easier to follow any instruction if we are all working with the same design) or we need some other method of defining each pot and trimmer that fits ANY IGSL, no matter how constructed, and will work for. That might be difficult.

A "standard" from you would allow those of us (ME for example!!) with the least knowledge of the way IGSL works (I am slowly getting there!) to follow you and the others far far better......

I even see slight problems (as it is not so marked on the schematic) with which Pot Disc is 1 and which is 2 (as you yourself call them I believe!). Also you appear to speak of values 1, 2 and 3 etc., but I don't know as to whether you are talking about 1 - 10, 0 - 9 or what, so the numbers mean nothing to me (not that I am so far that I need the numbers yet...)

Then there is the slight problem of the orientation of Potentiometers end connections (not the wiper of course) that I believe it was Simon B. that kindly gave some good tips which I followed exactly, but I did not see anyone saying "Yes" it was correct or "No" it wasn't, so I assume he was correct.......many thanks Simon.

Due to these small but important differences, it does mean that you could have 10 IGSLs each one different with regard to the way the Pots are orientated, or which tone low/high means etc etc.....which means problems for us beginners when trying to follow instructions and we are 180° "out of phase! so to say....

Please do not take any of this post as criticism, it is not meant to be negative, I am just trying to call your attention to the problems we beginners may be up against. When someone as important to us as yourself can give us instructions as to which trimmer refers to which tone for example, we are very grateful indeed, but we must know if it applies to our machine or not, don't you agree?

I leave it entirely up to you as to whether you do something about these queries or not, that is your choice, my main aim was only to point out the fact that some of the IGSLs already built, may be quite different to yours, making instructions more difficult to write and for us (me) to understand........

I know you are a busy man and if you don't have time, I am still happy anyway......

Sent with a very friendly personal regard for your excellent design improvements/changes/instructions/knowledge and friendship to us all here,

from

Andy