Any electronics wizard in here?

[Exuptoy]

Ok, I am after some advice. Please bear with me as the information below is mostly relevant.

About 10 years ago I picked up a Baldor 180V DC motor and gearbox with a Penta KBMD KB Electronics Multi Drive DC controller from a scrap conveyor system. I broached the drive cog from my garage roller shutter door to take a key, fitted it to my roller through the reduction gear then fitted a small chain puller wheel to the rear of the motor in case I ever needed to have a manual way to operate the shutter.

I purchased a remote interface for about £25 from fleebay and made up a small junction box containing 2 x contactor switching relays (240v control) and the only purpose they serve is to reverse the motor via the armature pos / neg outputs from the speed controller (I ran the A+ / A- connections from the output terminal of the SC through the both contactors so they are in effect interposing relays to ensure the outputs to the DC motor are either up or down) so I have remote up and down with a couple of limit switches which drop out the contactors when they are at full travel.

Not a very technical setup and slightly Heath Robinson I know but it works.......until yesterday when the unit fused the electrics in the garage and knocked out the garage breaker in the house.

I have removed the board from the speed controller housing and have found a transistor like device marked A68062 MEX T (which looking for the details on the net seems to be a Teccor brand TO-220 cased rectifier) but the details of which are quite scarce and I cannot find out much more about it.
Does anyone know if I can source a different Rectifier to replace this item? I think it popped as a lot of the metalwork in the garage has condensation on it and I think the inside of the controller must have been damp to cause it to track across the terminals and pop. There is also evidence of rust on the mild steel heatsink bar screwed across all five devices (2 of which are marked SCR 1&2 and 3 are marked D11-D12-D13).

 

[voipio]

There's very little concrete information to go on. At least some of the semiconductors are going to be triacs or SCRs rather than diodes. Are they all the same components?

It looks as if there has been a serious short circuit, looking at the legs on the second TO220 device in from the right, so simply replacing the one component might not be sufficient to effect a repair.

A good sealed box and cable entry glands or seals would help.


This thread contains an image of a suspiciously similar board: http://www.edaboard.com/thread294221.html

Another related link: http://www.cnczone.com/forums/archive/index.php/t-226672.html

 

[the snooper]

those are thyristors contact a few places and look for a newer equivalent, it seems those are obsolete when I searched for them couldn't even find a data sheet

 

[Exuptoy]

I am hoping the reason for the blowout is tracking as yesterday a lot of metalwork in the garage was wet due to condensation. Only one way to find out. A brand new KBMD control box is around £98 so if I have to go down that route then so be it but if I can change one component and cure it then all the better. The board was mounted inside a housing with glands but it is metal with no insulation.

I have inquired with Littlefuse who bought out Teccor a few years ago so they may have up to date info on a like for like component seeing as that is their business. There is also KBE the drive manufacturer who may give some feedback as I doubt they would entertain a repair on such an old bit of kit and it would be prohibitive anyway price wise as they are in the US.

Another option is there is an electronics company (Lektronix) who carry out repairs on kit for businesses and my mate works there so he said that he could take it in and see if it can be done for cash thru the back door.

Thanks for the input guys. Anyone else?

 

[WorkshopChris]

Quick google did bring up a reference indicating the possibility it may be a diode.
Does the pcb still contain a good one you could remove to test to verify it workings.
http://www.cnczone.com/forums/archive/index.php/t-226672.html
This sort of thing is always tricky if cant find a data sheet, could you follow the circuit back to reverse engineer what is function is.

EDIT > just seen post above i missed.look like we found the same page.
2nd edit does that say D13 next to the on next to it?

 

[Seadog]

I found a reference that suggested IGBT.

 

[the snooper]

Quick google did bring up a reference indicating the possibility it may be a diode.
Does the pcb still contain a good one you could remove to test to verify it workings.
http://www.cnczone.com/forums/archive/index.php/t-226672.html
This sort of thing is always tricky if cant find a data sheet, could you follow the circuit back to reverse engineer what is function is.

EDIT > just seen post above i missed.look like we found the same page.
2nd edit does that say D13 next to the on next to it?

don't know why they are referring to it as a diode, maybe because it can only pass current in one direction

 

[Exuptoy]

Thats why I thought it may be a rectifier diode. The most info I can find is when I look for rectifier and it is in the power circuit as when you switch on the power it just powers it up ready and just now if I try and power it up without even thinking about the operation of the door it wipes out the power to the garage. I seriously thing it is rectification of the power circuit but as I say I may be a sparky but this is beyond me, I am clutching at straws with minimal electronics knowledge.

 

[the snooper]

Thats why I thought it may be a rectifier diode. The most info I can find is when I look for rectifier and it is in the power circuit as when you switch on the power it just powers it up ready and just now if I try and power it up without even thinking about the operation of the door it wipes out the power to the garage. I seriously thing it is rectification of the power circuit but as I say I may be a sparky but this is beyond me, I am clutching at straws with minimal electronics knowledge.

an scr is a silicon controlled rectifier which is general electrics trade name for a thyristor

 

[Exuptoy]

Yeah, I understand that, but items 1 & 2 are marked SCR 1 & 2 but items 3 4 & 5 are marked D11, D12 & D13 which is why I started looking for A68062 Diode which then led me to TO-220 rectifiers with is when I found the items in the pic in the first post.

 

[WorkshopChris]

Have come across them in the past the configuration is like 2 diodes back to back sharing a centre leg.

 

[the snooper]

yours are not marked TO-220 are they ?

 

[the snooper]

Have come across them in the past the configuration is like 2 diodes back to back sharing a centre leg.

ive also seen them that way

 

[Seadog]

TO220 describes the encapsulation

 

[Exuptoy]

yours are not marked TO-220 are they ?

No, the only marks are A68062, MEX and the wigly letter T which is Teccor's symbol it would seem.

 

[WorkshopChris]

Any chance you can post up some clear pics of the front and back to the board so we can follow the layout.

 

[the snooper]

No, the only marks are A68062, MEX and the wigly letter T which is Teccor's symbol it would seem.

google your part number followed by thyristor, it brings up your part

 

[Exuptoy]

Any chance you can post up some clear pics of the front and back to the board so we can follow the layout.

Yeah, can do. Bear with me.

google your part number followed by thyristor, it brings up your part

Cheers Snooper

 

[Seadog]

They may be Triacs of course

 

[the snooper]