Need your help again. Syma S33 heli pcb

[Rs2k_Rider]

Hi all. Need your help again.

I have a Syma S33 heli that's broken, see a pattern here lol

Anyways.

The main rotors turn no problem, but the tail rotor has stopped. No forward or reverse [emoji31]

I have stripped it down and taken a pic of each side of the pcb.
I suspect it's dead transistors but not sure ....





The tail rotor connection is the one in the first pic above the transistors on the bottom left.
On the other side it is on the right hand side at the top of the legs of the transistors / next to the R010 resistors.

It looks like the connector traces to the middle pins on the bottom line of transistors - these are D882P G18.
What I was wondering, is I think these have failed due to upgrades for the tail rotor (bigger motor, more powerful) so fried something. What can I replace these with that are more powerful ?

Cheers

 

[Rs2k_Rider]

Anyone

 

[Rs2k_Rider]

Tumbleweed lol

 

[Rs2k_Rider]

Right. Been doing some digging.
It seems this D882P transistor is hard to find.

I've found the spec I think which is up to 40v and 3A.
1 emitter
2 Collector
3 Base.

Seems to cross to this - http://www.nteinc.com/specs/100to199/pdf/nte184.pdf

But the transistor is a different shape ? Will that matter ? It's also up to 60v but still 3A.

I was thinking of increasing the Amps to try prevent it blowing again, will that help or is t volts that will help ?
Arghhhh confused lol

 

[Spectre]

I think they are configured as a H bridge on that board but I don't know if the biasing is important in this application.

You would have to find devices with similar characteristics if it is important.

I'm having difficulty finding the datasheet.

Is there no-one talking about it on the RC forums?

 

[Rs2k_Rider]

I think they are configured as a H bridge on that board but I don't know if the biasing is important in this application.

You would have to find devices with similar characteristics if it is important.

I'm having difficulty finding the datasheet.

Is there no-one talking about it on the RC forums?

The only reference I can find to it (d882p) is referring to the one I've linked above

What's a H bridge ? Don't know if it matters but the motor can be powered in both directions so I would think the voltage can be reversed ?

 

[Spectre]

The only reference I can find to it (d882p) is referring to the one I've linked above

What's a H bridge ? Don't know if it matters but the motor can be powered in both directions so I would think the voltage can be reversed ?

Buy a new controller and put a light heatsink on them .

 

[Rs2k_Rider]

Buy a new controller and put a light heatsink on them .

£15 for new board which will probs blow again.....
How could a heatsink be mounted on these ? :-/

 

[Spectre]

£15 for new board which will probs blow again.....
How could a heatsink be mounted on these ? :-/

Heatsink adhesive, although there are special ones for TO-92 packages.

US stock unfortunately:

575200B00000G - AAVID THERMALLOY - HEAT SINK | Farnell element14

 

[Rs2k_Rider]

Heatsink adhesive, although there are special ones for TO-92 packages.

US stock unfortunately:

575200B00000G - AAVID THERMALLOY - HEAT SINK | Farnell element14

Hmm that's an idea. I'd much prefer to change the transistors to higher rated parts tho

 

[Spectre]

Hmm that's an idea. I'd much prefer to change the transistors to higher rated parts tho

Need to know the details of the ones present first though.

At least if you had a second board you could experiment.

 

[Rs2k_Rider]

Need to know the details of the ones present first though.

At least if you had a second board you could experiment.

This any use ?

http://www.datasheet4u.com/download_new.php?id=545690

 

[Spectre]

I doubt there has been anything like 3A through that motor though.

Seems a bit high.

 

[Rs2k_Rider]

I doubt there has been anything like 3A through that motor though.

Seems a bit high.

That did cross my mind. Although I have upgraded to motor to - http://pages.ebay.com/link/?nav=item.view&alt=web&id=221361839370

Don't know if that's popped them ?

The motor doesn't work it either direction, so I would guess both transistors are dead ? Which seems odd to me that both died.

 

[Spectre]

That did cross my mind. Although I have upgraded to motor to - http://pages.ebay.com/link/?nav=item.view&alt=web&id=221361839370

Don't know if that's popped them ?

The motor doesn't work it either direction, so I would guess both transistors are dead ? Which seems odd to me that both died.

Hmm, perhaps it is whatever supplies those transistors then.

 

[Rs2k_Rider]

Hmm, perhaps it is whatever supplies those transistors then.

Arghhh headache lol. The circuits so small I can't see where power goes. Other than to a resistor

I've ordered a new board, anyone fancy playing with this one ? Lol

 

[Magnu420]

i got a mate who does electronics,maybe he will have a go for you

 

[Rs2k_Rider]

Right replaced the two transistors in the lower left of the pic.
Now have forward motion on rear rotor but no rear ?
Could it also be the other transistors above the ones I've changed dead ?

Which leads me to, why have all transistors blown ?

 

[Spectre]

Right replaced the two transistors in the lower left of the pic.
Now have forward motion on rear rotor but no rear ?
Could it also be the other transistors above the ones I've changed dead ?

Which leads me to, why have all transistors blown ?

Both transistors in each leg of H-bridge on at the same time might do it. Not sure why that might happen though unless whatever drives them is faulty. Something causing a short in the motor?

H bridge - Wikipedia, the free encyclopedia

Difficult to tell without a schematic.

Don't think I saw any freewheel diodes in that circuit either. Shown here:

THS Engineering » Bidirectional PWM Motor Control

 

[Rs2k_Rider]

Both transistors in each leg of H-bridge on at the same time might do it. Not sure why that might happen though unless whatever drives them is faulty. Something causing a short in the motor?

H bridge - Wikipedia, the free encyclopedia

Difficult to tell without a schematic.

Don't think I saw any freewheel diodes in that circuit either. Shown here:

THS Engineering » Bidirectional PWM Motor Control

So the two left then two right, one above the other run together ? Forward/Reverse

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F. R.