GS 5 THRESHOLD PROBLEM

[daverave]

i once used a voltage converter with a surf pi using three li-ion batteries and it worked very well with a large elect capacitor on the output and the detector was very stable indeed.

[kt315]

we need full batch of board pics of GS5 in high resolution, high resolution is NOT 150kb, not 230, not 360 and not 1Mb.
high resolution is 5MB-10MB. high resolution is such as we see easely marking of values of SMD resistors.
we need both sides of the pcb pics. we need the information, not those noise why low drop and why not low drop.
we need new winter project for everybody.

[Ferric Toes]

i once used a voltage converter with a surf pi using three li-ion batteries and it worked very well with a large elect capacitor on the output and the detector was very stable indeed.

I have successfully used a MT3608 converter in a PI design and not had noise problems. However, a few precautions had to be taken. I added extra 5uF ceramic capacitors to the input and output pads. The MT3608 runs at 1.2MHz so it is easier to filter than lower frequency converters. The convertor was housed in a small screening box together with a -12V linear regulator. The MT3608 is of course a positive regulator but there seems no reason not to ground the + output and put the 7912 negative regulator on the minus side. You cannot ground the positive side of the battery with this arrangement.. Anyway, it works well and no additional noise. The 7912 could be replaced by a 7915 to give -15V and the trimmer on the MC3608 board adjusted for, say, 18V from the converter. For my -12V version, the input is from six NiMh AA cells, giving 7.2V. I have tried Li-ion cells and two in series would work fine, but they must have protection circuitry. Otherwise if the detector is inadvertently left switched on and the batteries discharged below 2.9V the batteries will likely fail. NiMh cells are more forgiving. I will take a picture of this arrangement and post shortly.

Eric.

[daverave]

Hi Eric...ive been the same and had no problems with noise whatsoever....to be honest i do prefer using straight battery power....i think it all depends on how light and compact you want to make the detector....but for high power detectors i think converters will drain the batteries much quicker....you mentioned about li-ion batteries failing below 2.9v volts...so if i risk discharging down to say 2.5v will i ruin the batteries ???

[kt315]

i see absolutely ununderstanding of some people that a batt is only a capacitor. i tell in the space and feeling yourself like full idiotic here.
i think capitalistic world does not have school education at all. bad.

i think our world is quickly and fast degrading on level of monkey.

[dbanner]

we need full batch of board pics of GS5 in high resolution, high resolution is NOT 150kb, not 230, not 360 and not 1Mb.
high resolution is 5MB-10MB. high resolution is such as we see easely marking of values of SMD resistors.
we need both sides of the pcb pics. we need the information, not those noise why low drop and why not low drop.
we need new winter project for everybody.

Requests have been made before, but to no avail. I personally don't see the big deal, since the GS5 is no longer in production, and sharing pics of PCB is not infringement of anything. So why not share pics? To prevent reverse engineering? Really? Don't make sense to me.
But If device was obtained on condition of promise not to publish any pics, then there isn't anything wrong with that either.
It is common occurrence of members to share pics of pcb with others on forum, nothing unusual or unethical or even illegal about that. But for a reasonable request to fall on deaf ears is a little impolite to say the least. Very curious indeed.

[kt315]

MPP was been buy (put right verb form), copied and selling on silver dog site. is MPP NOT Eric's made detector?

[Ferric Toes]

Hi Eric...ive been the same and had no problems with noise whatsoever....to be honest i do prefer using straight battery power....i think it all depends on how light and compact you want to make the detector....but for high power detectors i think converters will drain the batteries much quicker....you mentioned about li-ion batteries failing below 2.9v volts...so if i risk discharging down to say 2.5v will i ruin the batteries ???

Hi Dave, You are correct.
As the battery voltage falls, the converter will draw more current, which will cause the battery voltage fall faster and we have a runaway situation. There is a lot of information on the internet regarding the low voltage point for lithium batteries. This is particularly a point raised for radio controlled models. Some recommend getting the model in for a recharge when the battery is down to 3.5V per cell. My 2.9V even looks too low because as the battery is assumed to be under load, the voltage will fall fast. Cell damage will certainly have occurred at 2.5V. I have had this happen this myself and the battery cannot be recovered. They were not Chinese cheapos either. Whites battery packs for the TDi have inbuilt protective circuitry that prevents the voltage falling below the safe level. You can buy 18650 cells with protection, but the ones I have are longer and need a different battery holder.

Eric.

[dbanner]

MPP was been buy (put right verb form), copied and selling on silver dog site. is MPP NOT Eric's made detector?

You are correct. MPP is derived from Eric's Minipulse( two stage preamp added, also some other small changes). But the PCB from silver dog is unique and original to the kit. As for gs5, mr. Foster is simply giving technical support for his own product.
But I personally don't have any knowledge of the fiduciary dealings made between various parties, nor do I care. I simply enjoy the kits offered for sale. People are entitled to pursue their own legitimate entrepreneurial ambitions If that is their pleasure. Perfectly ok by me.
KT315, you can read between the lines, you are smart person. Ask yourself why is there only pic of top side of gs5 pcb here on forum, but no bottom side?
It is just how it is. Different mindset between those who have, and those who have not. It is sanctimonious hypocrisy.

[dbanner]

Hack old cell phone battery for protection circuitry board.

[daverave]

Hi Dave, You are correct.
As the battery voltage falls, the converter will draw more current, which will cause the battery voltage fall faster and we have a runaway situation. There is a lot of information on the internet regarding the low voltage point for lithium batteries. This is particularly a point raised for radio controlled models. Some recommend getting the model in for a recharge when the battery is down to 3.5V per cell. My 2.9V even looks too low because as the battery is assumed to be under load, the voltage will fall fast. Cell damage will certainly have occurred at 2.5V. I have had this happen this myself and the battery cannot be recovered. They were not Chinese cheapos either. Whites battery packs for the TDi have inbuilt protective circuitry that prevents the voltage falling below the safe level. You can buy 18650 cells with protection, but the ones I have are longer and need a different battery holder.

Eric.

Hi Eric...i will have to be more careful in future with my li-ion batteries.....normally i discharge down to around 2.7 volts....i have got some protection circuits for the li-ion batteries which i bought from china some years ago but never used them due to them taking up space in the battery box...maybe a better idea is to buy the batteries with the built in protection but i think they are slightly longer due to be button top type cells.

[kt315]

with two batts parrallel i do not need the protection board. i also charge them together in one time. my way is simplest way.
is nothing of reward difficulties on bare place.

[kt315]

Hack old cell phone battery for protection circuitry board.
-------
Eddy smart buddy gives you a balansir for no money. http://smartelectronix.biz/publ/pros...orov/1-1-0-101
just take and use.

[dbanner]

I just took apart an old lithium battery from Android phone. It was rated 2000mAh/7.4wh. very easy to remove the top of battery and there it was- a small pcb containing protection circuitry with label for b+ and b- . Easy hack. If you have these old batteries laying around,. Make use. But obviously test before using as it could be the reason why the battery failed in the first place. I think it's supposed to switch at 2.9 v for 3.7 v battery.

[daverave]

just been doing some research on the internet concerning li-ion discharge and it seems to vary according to the brand...but from what i can see most must not be discharged below 3 volts but some down to 2.7 volts...just hope i havent damaged any of my batteries.