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Author Topic: MAGIC SMOKE ALL THE WAY FROM HONG KONG  (Read 8445 times)

John W E

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MAGIC SMOKE ALL THE WAY FROM HONG KONG
« on: September 28, 2011, 08:33:31 PM »

Hi ya there everyone

I just installed  the EL MODEL ESC 110 amp speed controller into the model.   These are those which come from a well-known auction site - at roughly between £15 and I have actually seen one for £110 - the ones with the black case, with the aluminium finns sticking out from the top........its rated at 110 amps forward and 40 amps in reverse - under load - on test - in the bathtub - it lasted about 4.5 mins before the MAGIC SMOKE and that peculiar PONG of meltdown.....for those who are wondering about the set up - the motor was and luckily still is a Graupner 500BB VZ/operating voltage between 4.8 volts and 8.4 volts.    No load current is 1.6 amps and at maximum efficiency is (according to the box) 13.5 amp.    The battery pack used was a 7.2 - 250 mAh and this in turn is protected by a 15 amp fuse - the propeller on the model was a 35mm two blader racing prop.   When I did the test before I installed the speed controller, the current drawn by the motor was about 10.5 amps with this prop.   So all well within the specs and safety margins. When I gave it a test-run on the bench, everything ran normal and nice and cool.  Obviously either a) there has been a fault with the speed controller components or b) these speed controllers are nowhere near the rating advertised with them.

After the disaster and I had cleared all the smoke/fumes/pong/smell etc.....before me Mrs got home from work ...... I opened up the speed controller to find out one of the
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John W E

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #1 on: September 28, 2011, 08:38:32 PM »

 :-))
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John W E

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #2 on: September 28, 2011, 08:48:22 PM »

sorry I dont know what happened there.....

only half a message came out...


anyway

to finish off, one of the output transistors had fried and disintegrated along with parts of the electrical track - obviously either the components arent up to it.....or....I got a one off.    However, having made a close examination of the electrical track on the circuit board, I dont think this would be capable of taking anywhere near 110 amps.  The track itself is too narrow and also, it hasnt been beefed up or re-enforced.

I know there will be people who use these and are very happy with them - but - for anyone not in the know - I would offer a word of CAUTION.   They may be inexpensive - but - it didnt do the job I asked it to do and it was well within its limits.

For those who are wondering why I didnt buy HOME GROWN - speed controller, youknow what they say CURIOSITY KILLED THE CAT - in my case it killed the speed controller.

Aye
john
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DickyD

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #3 on: September 28, 2011, 08:50:26 PM »

Sorry John got to say it.  TOLD YOU SO.!!!!! %)
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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #4 on: September 28, 2011, 08:53:05 PM »

Mmmm, this happened to Dave,s (number 6) in his Solent the other weekend.... >:-o

Russ
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john s 2

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #5 on: September 28, 2011, 09:11:22 PM »

Yes sadly the Chinese tend to use different amps to us.It tends to be pot luck about reliability.Well known British ones can be repaired.Ive learnt my lesson and stick to tried ands tested.John.
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ACTion

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #6 on: September 28, 2011, 09:20:44 PM »

 %)............................ ;D
Dave M
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dodgy geezer

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #7 on: September 28, 2011, 09:57:52 PM »

   
They may be inexpensive - but - it didnt do the job I asked it to do and it was well within its limits.
 

I seem to remember reading that someone had opened one of these, checked the output transistors specs, and found that their spec was half that claimed for the ESC....

Assuming the components were specced correctly, you will find that the cheapest Chinese kit uses the cheapest untested components, which are going to have a high failure rate even working within their stated range....

And, finally, the cheapest kit will be cheap partly because no money is 'wasted' on quality control. So the item could fail because of poor soldering or loose wires causing a short....   

All in all, there are a lot of ways to lose with cheap kit....
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john44

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #8 on: September 28, 2011, 10:55:06 PM »

Quote
After the disaster and I had cleared all the smoke/fumes/pong/smell etc.....before me Mrs got home from work ...... I opened up the speed controller to find out one of the

Could say you bought the wrong pong from Hong Hong  %%

thanks for the info, I will buy British.

john
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irishcarguy

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #9 on: September 29, 2011, 09:24:53 AM »

I am using a very good British Made one & will continue to do so. When we fail to buy from the people that service our hobby locally they have a tendency to disappear & then we wonder why. When we go for cheap ( we all do at times, me included ) it turns out to be a race to the bottom. My motto now is buy the best quality you can afford but by all means check your prices, always bearing in mind good service & quality is also part of the price you are paying. Mick B.
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Mick B.

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #10 on: September 29, 2011, 09:40:25 AM »


thanks for the info, I will buy British.

john

I've got to say, smugly, I always do..........wouldn't entertain chinese electronics after watching a BBC watchdog prog once a while ago....frightening.
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John W E

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #11 on: September 29, 2011, 01:19:48 PM »

Hi I had very strong doubts about the true capabilities of this cheap honky pongee speed controller when I received it – due to the finicky size of the thing.  I mean when you deal with 110 amps you are looking at big heavy cables and big heat sinks and this speed controller just does not have them.

 

As for buying British I do normally and at one time I was a die hard Electronize man, having built a lot of their electronic speed controller kits, but, in my eyes Electronize has not really expanded their range of electronic products for us model boaters.  Still waiting for a mixer unit witch was promised some ten years ago  O0 not saying there is anything wrong with the speed controllers but the company attitude reminds me of the British motor bike industries attitude with not looking over their shoulder until to late! So as they say ‘one moves on to a British manufacturer who move with the times (sometimes)  %) %) %) ;D

 

But, having said all of that, we must still look at all new products that come into the modelling field for us and try them out even if some  are too good to be true…….

 

And last but not least  {-) {-) {-)

 

I said it was the output transistors that had fried, but in my haste to post - I got it wrong - it was the switching transistors that fried.

 

For those who are wondering,some speed controllers such as ACtion use a relay to switch the power to your motor forward and backwards, this is a semi-mechanical device (an electronical magnet moving a steel contact back and forth ) and the Hong Pong one uses a solidstate (no moving parts ) transistor.

 

aye

john

 
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ACTion

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #12 on: September 29, 2011, 01:43:24 PM »

I said it was the output transistors that had fried, but in my haste to post - I got it wrong - it was the switching transistors that fried.
john  
How curious. Logically they need only be low voltage and very low current devices. John is correct in that our Condor range of ESCs use a relay, but our P93 and P98 ESCs are relayless, like this 'orrible thing, and use very cheap-and-cheerful 2N7000 devices for switching the big MOSFETs. One wonders how the designer managed to put them in the firing line, so to speak. Maybe it's the BEC..................... %)
DM
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John W E

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #13 on: September 29, 2011, 02:24:31 PM »

Hi Dave,

 

The first thing I did to the thing was to remove the old bust transistor from the board and repair the electrical track.  I then reconnected it back up to a supply voltage and motor, plus radiogear to see if there was any life left in the thing and there was. But, the motor only run in one direction; plus it also had the dead band stop in the right place; centre off/on stick so that lead me to think I was dealing with the switching side of things so replaced the old ‘tranny’with one from the  that will do transistor draw and the speed controller was put on a life support  {-) {-) %) Summit not right with it though it runs nice and cool on a small load e.g. low drain 400 motor, but if you put any load on the motor that new transistor that i replaced  heats up sooooo quick

aye

john
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malcolmfrary

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #14 on: September 29, 2011, 03:52:42 PM »

The relay reversing ESCs typically have one (BIG) transistor for switching the motor on and off, plus a less hefty one for switching the relay, which should only operate for reverse. 
When you have a reversing ESC with no relay, there are basically two sets of output transistors, one set for forward, one set for reverse.  Each set has a transistor hanging off the ground line (big thick black wire), and another off the positive supply (big thick red wire).  This arrangement is often called a "H" bridge, because that's what it looks like on the diagram, top left and bottom right switch on together for forward, bottom left and top right for reverse, with the motor forming the bar across the middle.  To get a higher forward current handling capability, it is common practice to parallel extra transistors.   If the manufacturer decides that one of the positive transistors can handle the full load, extra forward current might cause an extra negative side one to be added to beef up forward current handling.  This assumes that the wire and tracks can handle it.  The wire needs a big enough cross section to handle current without overheating, the tracks need a combination of cross sectional area, and a big enough surface area so as to be able to dissipate any heat generated.
If one transistor fails to switch off, when its opposite number switches on, there is a dead short across the power supply.  Irrespective of whether the transistors can handle the rated current, Oriental Amps or real world ones, something will give.  It may well be that the dead one didn't have a full, proper contact with the heatsink, causing it to cook itself, letting out the magic smoke thus giving the strong wrong pong from Hong Kong.  Just thinking aloud.
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ACTion

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #15 on: September 29, 2011, 04:17:29 PM »

Just thinking aloud.
Doc
Is it called 'telepathy' when you  think aloud and it's my  head that aches?  ok2
CU at Glack-cool for a gottle of geer.
DM
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malcolmfrary

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #16 on: September 29, 2011, 05:56:15 PM »

Doc
Is it called 'telepathy' when you  think aloud and it's my  head that aches?  ok2
CU at Glack-cool for a gottle of geer.
DM
No.  It just means that the force was with me.  However briefly.
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MikeA

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #17 on: September 29, 2011, 06:38:29 PM »

i have quite a few various hong kong electricals and theyve all worked for me actually. i was about to buy this esc aswell glad i didnt now.
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John W E

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #18 on: September 29, 2011, 08:52:25 PM »

hi there,  its a bad sign when you begin to understand what Malcolm is on about....I must keep on taking me tablets.......Help! I think I'm melting! This is all your fault! - C3PO

or as Darth said The Force is strong with this one.  %% %% %%

Anyway, here is something to ponder over these speed controllers which have no relay; and which are rated like this Melted one  :(( rate at 110 amps forward mode and 40 amps reverse mode - hell that sounds like me in a morning =- how can one tell you have the motor the right way round, it may be the boat is going forward but the speed controller connected up in reverse without knowing it - so its actually running on the 40 amp side of things for forward motion.    No good shoving a volt meter across the proves, cos its the same voltage running forward and reverse.

Last but not least on this actual meltdowner the thing that was really tricky - there is or WAS no off/on switch for the BEC.    So once plugged into the battery it was live.

When you used the speed controller on the 2.4 setup - it didn't half create some problems with the Planet T5.

aye
john

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malcolmfrary

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #19 on: September 30, 2011, 10:10:02 AM »

Quote
how can one tell you have the motor the right way round, it may be the boat is going forward but the speed controller connected up in reverse without knowing it
All other things being equal, when setting up, make sure that the transmitter is set to "normal" rather than "reverse".  The receiver will pass the information on and the ESC, when told to do a forward, will do so, offering the alleged 110A capability.  When the TX stick tells it reverse, the other pair of output transistors is brought into play, and 40A is offered.
It is important to set the gear up with the sticks set to normal as far as possible.  In the case of this type of ESC, it leaves you using the higher current components, in the case of a relay reverser, you dont want to do most of your running with the relay operated since this will either flatten your RX battery very quickly or, if you have a BEC, might take that up to its overload point.
Having said all that, when using the ESCs with different f/r figures, always take the smaller of the two as the maximum.  Not totally safe, but safer than trusting to the miniaturised Oriental Amps.  (Small, but beautifully marked"
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dodgy geezer

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #20 on: September 30, 2011, 11:26:22 AM »

My understanding of the way Chinese manufacturing works is that there is no real enforcement of copyright or brand quality control, and a lot of components are sub-contracted out.

So an original design will be obtained, often from a western company who is having something made in China. That design will probably work. The Chinese companies which are tooled up to make the casings, pcbs and everything else will make these to the original specs if they are being paid to do so, and the product will be sold by the western company with no problems.

While this happens, the Chinese sub contractors may run off more parts and sell them to other companies in China. There will be rejected production runs with quality failings - these will also get onto the local market. Local entrepreneurs may buy these parts cheaply and construct complete units which can then be sold as brandless items. Some of these might be the equal of the original branded item - many will have various defects - in many cases cheaper low-spec components will be substituted to lower the price. In some cases a local re-design will be undertaken to slightly differentiate the appearance of an item, lower the build price, or change a metal component to a plastic one.

You can see this happening in the case of small Chinese lathes - the original design was Russian. A bit agricultural, but satisfactory. The Chinese took the design, substituted simple lower quality ball races for the more expensive taper roller headstock bearings, and started to produce cheap lathes, quite often with poor castings which are now being slowly improved. And again with the little micro video cameras which we often use on our boats - the original expensive Veho Muvi design had a metal framework and cost a lot - the Chinese rip-off is only a few pounds and comes in a bewildering array of undocumented variations, depending on which components happened to be available when that run was being put together. This site is quite instructive:  
    
http://www.chucklohr.com/808/#ComparisonOfVersions

For situations where the consumer is capable of judging quality at point of sale, such as, perhaps, jeans, this process provides cheap goods of adequate quality, though breaching the original companies rights to hold the price high. Where the consumer cannot check the quality......  {:-{ {:-{



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Number 6

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Re: MAGIC SMOKE ALL THE WAY FROM HONG KONG
« Reply #21 on: October 02, 2011, 03:03:57 PM »

Mmmm, this happened to Dave,s (number 6) in his Solent the other weekend.... >:-o

Russ

Too right, not very impressed, got just two words to say...never again!  {:-{ >:-o {:-{
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pettyofficernick

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Chineas 120A???? ESC
« Reply #22 on: June 16, 2012, 03:48:15 PM »

Good afternoon all, has anyone tried one of these controllers? A friend had this one in an original Aerokits Sea Queen, in whichHe had fitted a Caldercraft 750S motor, as soon as the boat went to about half speed, smoke shot from the boat, luckily he was able to bring the boat back in under its own momentum.He is using a 40mm 3 blade prop. The Chinese claim these units are rated at 120A don't believe a word of it myself. they also claim they are waterproof, even though you can see inside the case where the wiring exits. Can anyone recommend an ESC that will handle a 750 motor. Power is supplied by a 12V SLA.
Thanks in advance,
Nick.



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ACTion

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Re: Chineas 120A???? ESC
« Reply #23 on: June 16, 2012, 04:04:54 PM »

This one will do the job easily (BTW we use British Amps.............)
http://www.action-electronics.co.uk/pdfs/P98.pdf
DM
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pettyofficernick

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Re: Chineas 120A???? ESC
« Reply #24 on: June 16, 2012, 05:06:03 PM »

Many thanks ACTion, btw, what is the difference between English amps and Chinese ones?
Many thanks,
Nick
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