Li-ion power mod

Re: Li-ion power mod

Postby UnKaiF » Fri Mar 02, 2018 3:43 pm

upsss wrote:As far as regulating the 3.3V supply directly from the Li-Ion battery, it is a bad idea. Draining a Li-Ion battery down to 3.0V or even 2.8V is perfectly acceptable...

Yes. You are 100% right. On my drafts only the principle is reflected. The protection devices are not shown there. Moreover, a low voltage alarm will be a good idea.
upsss wrote: Regulating the 3.3V supply directly from the Li-Ion battery as you are suggesting, your new LDO 3.3V regulator will stop regulation under worst condition with battery voltage of 3.6-3.7V,

Absolutely NOT!
See the regulator's datasheet. Moreover, I tested XC6203 in practice. It works normal down to 3.3 volts, and then just repeats the input voltage.
upsss wrote:BTW, my DSO runs with my 1340mAh battery for about 4.5 hours...

Using the proposed design, you can double this time (or so). Is it so hard to believe? I never publish unverified things. (My practical implementation has been tested. The circuit solutions are somewhat redundant [in terms of the number of components], and, moreover, are assembled on the DIY PCB. So I do not publish it here).
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Re: Li-ion power mod

Postby upsss » Sat Mar 03, 2018 7:45 am

UnKaiF wrote:
upsss wrote: Regulating the 3.3V supply directly from the Li-Ion battery as you are suggesting, your new LDO 3.3V regulator will stop regulation under worst condition with battery voltage of 3.6-3.7V,

Absolutely NOT!
See the regulator's datasheet. Moreover, I tested XC6203 in practice. It works normal down to 3.3 volts, and then just repeats the input voltage.

Of course I looked at the regulator datasheet. When I said that at worst case, with battery voltage of ~3.6V your regulator will stop regulating, THAT IS EXACTLY WHAT WILL HAPPEN. I didn't say and I didn't mean that the regulator output will drop to 0V. Once such a regulator stops regulating the output voltage, the regulator becomes unstable and totally unpredictable. Under those conditions, the manufactures would not guarantee ANY of device parameters and that is a FACT regardless of your personal experience with a couple of their devices.

Hey, you can do whatever you want to do, but as an EE with decades of hardware design experience, I cannot not to critique your suggestions. As far as my battery run time, I would have been happy with only 2hr, for me this scope is only a little toy.
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Re: Li-ion power mod

Postby UnKaiF » Sat Mar 03, 2018 6:26 pm

[sarcasm ON]
OK. If you need a theoretically and "racially correct" solution for this little toy - use something like this.
[sarcasm OFF]
Suggestions on the drafts above is a tradeoff, why don't you understand ?
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Re: Li-ion power mod

Postby UnKaiF » Sun Mar 04, 2018 2:02 pm

Please forgive me if I was somewhat rude. You are partly right.
Of cource, the regulator MAY be unstable when difference between the input and output voltages becomes small. But it does not stop regulating ! Simply, the characteristic becomes nonlinear, which facilitates self-oscillations. Whether it oscillate or not - depends on the form of the [complex] characteristic and the external conditions. In my case, in practice, this does not happen. Here's what we see in the manufacturer's notes:
Torex_notes_on_use.png

That's all.
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Re: Li-ion power mod

Postby RobNL » Sun Mar 04, 2018 8:18 pm

Very nice stepup module with powerindicator and on/off !
https://www.ebay.com/itm/5V-2-1A-Charge ... 2812405137
In combination with this item you have 9 Volt, you only need the module not the wires or connectors but it is allin :D
https://www.ebay.com/itm/USB-DC-5V-to-D ... Goh4da8ooA
CU, Rob
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Re: Li-ion power mod

Postby upsss » Sun Mar 04, 2018 9:01 pm

UnKaiF wrote:Please forgive me if I was somewhat rude. You are partly right.
Of cource, the regulator MAY be unstable when difference between the input and output voltages becomes small. But it does not stop regulating ! Simply, the characteristic becomes nonlinear, which facilitates self-oscillations. Whether it oscillate or not - depends on the form of the [complex] characteristic and the external conditions. In my case, in practice, this does not happen. Here's what we see in the manufacturer's notes:
Torex_notes_on_use.png

That's all.

According to the datasheet, Max. Vout=3.366V, Max. Drop Out=0.22V, not taking into account Line Regulation, Load Regulation and Output Ripple you need Min. of 3.586V. By definition, anything less than that, the regulator will stop regulating the output. Unstable output and oscillation is the last thing you would want from any voltage regulator especially in a scope where you try to measure and display signals in the mV range.

I think we beat this thing to death so this will be my last comment.
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Re: Li-ion power mod

Postby RogJ07 » Sun Mar 18, 2018 4:57 am

Hi everyone

I share with you my mod
- 3.7V 650mAh battery from a dead DECT phone (ref 660177)
-micro charger based on TP 4056
- Step-up DC/DC converter with MT3608

I will try to install a battery indicator that I have ordered

DSO01.jpg


With protective screen
DSO02.jpg


;)
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Re: Li-ion power mod

Postby Mike » Tue Mar 20, 2018 7:29 pm

Here is my mod.

I managed to install a 2200mAh battery inside the DSO for over 10h of runtime. :D
I had to modify some things (dial, housing, switch, stepup and charger pcb, and so on), but it worked.

I also drilled holes to have access to the bootload-pins and the serial interface, so i never have to reopen the housing.
Attachments
IMG_20180319_214633.jpg
IMG_20180319_214625.jpg
IMG_20180224_230847.jpg
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Re: Li-ion power mod

Postby Diabolo » Wed Mar 21, 2018 7:55 pm

Hello,

For people who want to simplify their lives, there is this:
- https://www.ebay.fr/itm/DSO150-Shell-fo ... 0011.m1850


Diabolo
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Re: Li-ion power mod

Postby RobNL » Wed Mar 21, 2018 7:58 pm

Diabolo wrote:Hello,

For people who want to simplify their lives, there is this:

Diabolo


Some call this SPAM
CU, Rob
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