Forums

Somewhat over-engineered for a lipo charger?

Started by Cursitor Doom August 17, 2015
I think the guy who designed this single cell charger for LiPo batteries 
must have been paid by number of components used. I've no idea what half 
of this stuff is supposed to do. This model was produced in 2002 for a 
couple of years. 
What d'yall make of it?

Only the first 3 pictures in this folder, guys. The rest of the pictures 
are of something else entirely out of a scope, so just ignore them:

https://www.flickr.com/photos/128859641@N02/with/16913890862/

"Cursitor Doom" <curd@notformail.com> wrote in message 
news:mqtkqm$ivd$1@dont-email.me...
>I think the guy who designed this single cell charger for LiPo batteries > must have been paid by number of components used. I've no idea what half > of this stuff is supposed to do. This model was produced in 2002 for a > couple of years. > What d'yall make of it? > > Only the first 3 pictures in this folder, guys. The rest of the pictures > are of something else entirely out of a scope, so just ignore them: > > https://www.flickr.com/photos/128859641@N02/with/16913890862/ >
How so? I see, hmm, http://www.datasheetarchive.com/dl/Datasheet-055/DSA0031803.pdf DH0165 switching controller (and associated components: diode+TVS clamp, capacitors, rectifiers, filter) TSM104A = quad op-amp plus ref, roughly a low current LM324 + TL431 in one (I wouldn't even be surprised if an x-ray shows two dies). Probably for voltage/current regulation/monitoring? ST52TO1C6 / MPACE0320D = ??? Can't find anything on this. Can you confirm my reading? I would guess it's a battery management device. Or some MCU. Not sure what all the transistors are for, but it would seem like they happened to need a lot of level shifting or logic and it wasn't worth putting in gates to do it. Tim -- Seven Transistor Labs Electrical Engineering Consultation Website: http://seventransistorlabs.com
On Tue, 18 Aug 2015 14:00:27 +1000, Tim Williams <tmoranwms@charter.net>  
wrote:

> > "Cursitor Doom" <curd@notformail.com> wrote in message > news:mqtkqm$ivd$1@dont-email.me... >> I think the guy who designed this single cell charger for LiPo batteries >> must have been paid by number of components used. I've no idea what half >> of this stuff is supposed to do. This model was produced in 2002 for a >> couple of years. >> What d'yall make of it? >> >> Only the first 3 pictures in this folder, guys. The rest of the pictures >> are of something else entirely out of a scope, so just ignore them: >> >> https://www.flickr.com/photos/128859641@N02/with/16913890862/ >> > > How so? I see, hmm, > http://www.datasheetarchive.com/dl/Datasheet-055/DSA0031803.pdf > DH0165 switching controller (and associated components: diode+TVS clamp, > capacitors, rectifiers, filter) > > TSM104A = quad op-amp plus ref, roughly a low current LM324 + TL431 in > one (I wouldn't even be surprised if an x-ray shows two dies). Probably > for voltage/current regulation/monitoring? > > ST52TO1C6 / MPACE0320D = ??? Can't find anything on this. Can you > confirm my reading? > > I would guess it's a battery management device. Or some MCU. Not sure > what all the transistors are for, but it would seem like they happened > to need a lot of level shifting or logic and it wasn't worth putting in > gates to do it. > > Tim >
ST52 perhaps some kind of 8051 clone/copy/derivative ?
On 18-Aug-15 1:03 PM, David Eather wrote:
> On Tue, 18 Aug 2015 14:00:27 +1000, Tim Williams <tmoranwms@charter.net> > wrote: > >> >> "Cursitor Doom" <curd@notformail.com> wrote in message >> news:mqtkqm$ivd$1@dont-email.me... >>> I think the guy who designed this single cell charger for LiPo batteries >>> must have been paid by number of components used. I've no idea what half >>> of this stuff is supposed to do. This model was produced in 2002 for a >>> couple of years. >>> What d'yall make of it? >>> >>> Only the first 3 pictures in this folder, guys. The rest of the pictures >>> are of something else entirely out of a scope, so just ignore them: >>> >>> https://www.flickr.com/photos/128859641@N02/with/16913890862/ >>> >> >> How so? I see, hmm, >> http://www.datasheetarchive.com/dl/Datasheet-055/DSA0031803.pdf >> DH0165 switching controller (and associated components: diode+TVS >> clamp, capacitors, rectifiers, filter) >> >> TSM104A = quad op-amp plus ref, roughly a low current LM324 + TL431 in >> one (I wouldn't even be surprised if an x-ray shows two dies). >> Probably for voltage/current regulation/monitoring? >> >> ST52TO1C6 / MPACE0320D = ??? Can't find anything on this. Can you >> confirm my reading? >> >> I would guess it's a battery management device. Or some MCU. Not >> sure what all the transistors are for, but it would seem like they >> happened to need a lot of level shifting or logic and it wasn't worth >> putting in gates to do it. >> >> Tim >> > > ST52 perhaps some kind of 8051 clone/copy/derivative ?
I think it may be ST62, which is an 8bit uC <http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/CD00018961.pdf?s_searchtype=keyword>
On 8/17/2015 4:48 PM, Cursitor Doom wrote:
> I think the guy who designed this single cell charger for LiPo batteries > must have been paid by number of components used. I've no idea what half > of this stuff is supposed to do. This model was produced in 2002 for a > couple of years. > What d'yall make of it? > > Only the first 3 pictures in this folder, guys. The rest of the pictures > are of something else entirely out of a scope, so just ignore them: > > https://www.flickr.com/photos/128859641@N02/with/16913890862/ >
I'm thinking lipo suction may be in order here.
On Tue, 18 Aug 2015 15:03:32 +1000, David Eather wrote:

> ST52 perhaps some kind of 8051 clone/copy/derivative ?
There's a thumping great fat power diode immediately to the right of the transformer. What's that doing there??
On Mon, 17 Aug 2015 23:00:27 -0500, Tim Williams wrote:

> How so? I see, hmm, > http://www.datasheetarchive.com/dl/Datasheet-055/DSA0031803.pdf DH0165 > switching controller (and associated components: diode+TVS clamp, > capacitors, rectifiers, filter) > > TSM104A = quad op-amp plus ref, roughly a low current LM324 + TL431 in > one (I wouldn't even be surprised if an x-ray shows two dies). Probably > for voltage/current regulation/monitoring? > > ST52TO1C6 / MPACE0320D = ??? Can't find anything on this. Can you > confirm my reading?
Close! It's actually ST*6*2TO1C6 / MPACE0320D The chip below left of that is marked: M104AI / 9N3316 The quartic shaped device immediately above the white socket is an STA353YT1
> I would guess it's a battery management device. Or some MCU. Not sure > what all the transistors are for, but it would seem like they happened > to need a lot of level shifting or logic and it wasn't worth putting in > gates to do it.
"Julian Barnes"  wrote in message news:mquo94$uum$1@dont-email.me...
> >On Tue, 18 Aug 2015 15:03:32 +1000, David Eather wrote: > >> ST52 perhaps some kind of 8051 clone/copy/derivative ? > >There's a thumping great fat power diode immediately to the right of the >transformer. What's that doing there??
Output side rectifier -- it's a flyback topology SMPS. Guessing B340 or somewhere around there? Likewise, the capacitor just above the opto (C11?) is the main filter cap. (If you have some of these that are wheezing, that would be a prime suspect, as well as C01 and, can't make it out, but it's right beside the "U01" label.) D07 is the primary side aux supply rectifier. Oh, and D51 seems to be supplying a second voltage rail on the secondary, just noticing that. Which goes right over to U41 (the opamp/ref), which might be for high-side current sensing? (It doesn't have a common mode range that includes the positive supply, so that would be helpful.) Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: http://seventransistorlabs.com
"Cursitor Doom"  wrote in message news:mqupns$uum$2@dont-email.me...
>Close! It's actually ST*6*2TO1C6 / MPACE0320D > >The chip below left of that is marked: M104AI / 9N3316 > >The quartic shaped device immediately above the white socket is an >STA353YT1
Ahh, that explains it. 8 bit MCU, 2k OTP prog, might as well be your bargain basement 8051! Euch, stack levels, maybe PIC would be more apt. Looks like the STA part (2A 40V PNP, roughly equivalent to, oh, halfway between 2N4403 and TIP31?) might be high side control or sense. Maybe it's got a discrete LDO post-regulator, or they're just turning it off when complete (since after all, the charger can't keep its brains running if it actually shut down the main supply..). R47 would be current sense (0.1 ohm). Thinking the quad op-amp is for voltage and current sense, the MCU orchestrates everything (possibly including current programming), and the dusting of transistors and resistors is for level shifting and feedback gain ratios. Current could also be controlled by feedback to the TL431 (or whatever it is exactly), in which case the STA353 would only be needed to disconnect the battery when charging is complete. A current sense resistor would be needed in either case, but being positioned near the transistor, and having enough op-amps to go around, it's probably a current source. That should be a pretty complete "rough" description of everything; if you want to learn more, I'd suggest picking up some appnotes on the devices (or related, e.g. TOPSwitch SMPS controllers; battery management chips; etc.), and if you want the schematic for further study, knock the components off and trace the connections. For MCU code, you might be able to hack a config pin to read it out (how this might be done, is not obvious, and very device specific), but it's quite possible you'd need to decap it and read bits with a microscope. A behavioral model is probably much cheaper to derive (run it through its paces and see what the controller does; synthesize your own replacement and compare results) than any of these methods. Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: http://seventransistorlabs.com
On Tue, 18 Aug 2015 07:19:30 -0500, Tim Williams wrote:

> Output side rectifier -- it's a flyback topology SMPS. Guessing B340 or > somewhere around there?
I'm somewhat bemused about the need for this size of diode, too. Having hooked it out, it turns out to be an SR306 which according to the datasheet is a Schottky good for 3A forward current. Given the stated output current max is about 750mA, this does seem very generously specified. :-/